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-rw-r--r--Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt58
-rw-r--r--Documentation/devicetree/bindings/display/bridge/ti,ths813x.txt (renamed from Documentation/devicetree/bindings/display/bridge/ti,ths8135.txt)13
-rw-r--r--Documentation/devicetree/bindings/display/connector/dvi-connector.txt1
-rw-r--r--Documentation/devicetree/bindings/display/etnaviv/etnaviv-drm.txt24
-rw-r--r--Documentation/devicetree/bindings/display/msm/dsi.txt26
-rw-r--r--Documentation/devicetree/bindings/display/panel/arm,versatile-tft-panel.txt31
-rw-r--r--Documentation/devicetree/bindings/display/panel/auo,g104sn02.txt12
-rw-r--r--Documentation/devicetree/bindings/display/panel/display-timing.txt5
-rw-r--r--Documentation/devicetree/bindings/display/panel/koe,tx31d200vm0baa.txt25
-rw-r--r--Documentation/devicetree/bindings/display/panel/orisetech,otm8009a.txt2
-rw-r--r--Documentation/devicetree/bindings/display/panel/raydium,rm68200.txt25
-rw-r--r--Documentation/devicetree/bindings/display/panel/simple-panel.txt4
-rw-r--r--Documentation/devicetree/bindings/display/renesas,du.txt35
-rw-r--r--Documentation/devicetree/bindings/display/rockchip/cdn-dp-rockchip.txt74
-rw-r--r--Documentation/devicetree/bindings/display/st,stm32-ltdc.txt2
-rw-r--r--Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt104
-rw-r--r--Documentation/devicetree/bindings/vendor-prefixes.txt1
-rw-r--r--Documentation/devicetree/overlay-notes.txt4
-rwxr-xr-xDocumentation/features/list-arch.sh2
-rw-r--r--Documentation/gpu/drivers.rst21
-rw-r--r--Documentation/gpu/drm-kms.rst8
-rw-r--r--Documentation/gpu/index.rst9
-rw-r--r--Documentation/gpu/kms-properties.csv1
-rw-r--r--Documentation/gpu/todo.rst17
-rw-r--r--Documentation/isdn/INTERFACE.CAPI2
-rw-r--r--Documentation/isdn/README4
-rw-r--r--Documentation/isdn/README.FAQ4
-rw-r--r--Documentation/isdn/README.gigaset16
-rw-r--r--Documentation/locking/lockdep-design.txt51
-rw-r--r--Documentation/memory-barriers.txt34
-rw-r--r--Documentation/timers/NO_HZ.txt7
31 files changed, 516 insertions, 106 deletions
diff --git a/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt b/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt
new file mode 100644
index 000000000000..4f0ab3ed3b6f
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/renesas,lvds.txt
@@ -0,0 +1,58 @@
+Renesas R-Car LVDS Encoder
+==========================
+
+These DT bindings describe the LVDS encoder embedded in the Renesas R-Car
+Gen2, R-Car Gen3 and RZ/G SoCs.
+
+Required properties:
+
+- compatible : Shall contain one of
+ - "renesas,r8a7743-lvds" for R8A7743 (RZ/G1M) compatible LVDS encoders
+ - "renesas,r8a7790-lvds" for R8A7790 (R-Car H2) compatible LVDS encoders
+ - "renesas,r8a7791-lvds" for R8A7791 (R-Car M2-W) compatible LVDS encoders
+ - "renesas,r8a7793-lvds" for R8A7793 (R-Car M2-N) compatible LVDS encoders
+ - "renesas,r8a7795-lvds" for R8A7795 (R-Car H3) compatible LVDS encoders
+ - "renesas,r8a7796-lvds" for R8A7796 (R-Car M3-W) compatible LVDS encoders
+ - "renesas,r8a77970-lvds" for R8A77970 (R-Car V3M) compatible LVDS encoders
+ - "renesas,r8a77995-lvds" for R8A77995 (R-Car D3) compatible LVDS encoders
+
+- reg: Base address and length for the memory-mapped registers
+- clocks: A phandle + clock-specifier pair for the functional clock
+- resets: A phandle + reset specifier for the module reset
+
+Required nodes:
+
+The LVDS encoder has two video ports. Their connections are modelled using the
+OF graph bindings specified in Documentation/devicetree/bindings/graph.txt.
+
+- Video port 0 corresponds to the parallel RGB input
+- Video port 1 corresponds to the LVDS output
+
+Each port shall have a single endpoint.
+
+
+Example:
+
+ lvds0: lvds@feb90000 {
+ compatible = "renesas,r8a7790-lvds";
+ reg = <0 0xfeb90000 0 0x1c>;
+ clocks = <&cpg CPG_MOD 726>;
+ resets = <&cpg 726>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ port@0 {
+ reg = <0>;
+ lvds0_in: endpoint {
+ remote-endpoint = <&du_out_lvds0>;
+ };
+ };
+ port@1 {
+ reg = <1>;
+ lvds0_out: endpoint {
+ };
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/display/bridge/ti,ths8135.txt b/Documentation/devicetree/bindings/display/bridge/ti,ths813x.txt
index 6ec1a880ac18..df3d7c1ac09e 100644
--- a/Documentation/devicetree/bindings/display/bridge/ti,ths8135.txt
+++ b/Documentation/devicetree/bindings/display/bridge/ti,ths813x.txt
@@ -1,11 +1,16 @@
-THS8135 Video DAC
------------------
+THS8134 and THS8135 Video DAC
+-----------------------------
-This is the binding for Texas Instruments THS8135 Video DAC bridge.
+This is the binding for Texas Instruments THS8134, THS8134A, THS8134B and
+THS8135 Video DAC bridges.
Required properties:
-- compatible: Must be "ti,ths8135"
+- compatible: Must be one of
+ "ti,ths8134"
+ "ti,ths8134a," "ti,ths8134"
+ "ti,ths8134b", "ti,ths8134"
+ "ti,ths8135"
Required nodes:
diff --git a/Documentation/devicetree/bindings/display/connector/dvi-connector.txt b/Documentation/devicetree/bindings/display/connector/dvi-connector.txt
index fc53f7c60bc6..207e42e9eba0 100644
--- a/Documentation/devicetree/bindings/display/connector/dvi-connector.txt
+++ b/Documentation/devicetree/bindings/display/connector/dvi-connector.txt
@@ -10,6 +10,7 @@ Optional properties:
- analog: the connector has DVI analog pins
- digital: the connector has DVI digital pins
- dual-link: the connector has pins for DVI dual-link
+- hpd-gpios: HPD GPIO number
Required nodes:
- Video port for DVI input
diff --git a/Documentation/devicetree/bindings/display/etnaviv/etnaviv-drm.txt b/Documentation/devicetree/bindings/display/etnaviv/etnaviv-drm.txt
index 05176f1ae108..8def11b16a24 100644
--- a/Documentation/devicetree/bindings/display/etnaviv/etnaviv-drm.txt
+++ b/Documentation/devicetree/bindings/display/etnaviv/etnaviv-drm.txt
@@ -1,23 +1,3 @@
-Etnaviv DRM master device
-=========================
-
-The Etnaviv DRM master device is a virtual device needed to list all
-Vivante GPU cores that comprise the GPU subsystem.
-
-Required properties:
-- compatible: Should be one of
- "fsl,imx-gpu-subsystem"
- "marvell,dove-gpu-subsystem"
-- cores: Should contain a list of phandles pointing to Vivante GPU devices
-
-example:
-
-gpu-subsystem {
- compatible = "fsl,imx-gpu-subsystem";
- cores = <&gpu_2d>, <&gpu_3d>;
-};
-
-
Vivante GPU core devices
========================
@@ -32,7 +12,9 @@ Required properties:
- clocks: should contain one clock for entry in clock-names
see Documentation/devicetree/bindings/clock/clock-bindings.txt
- clock-names:
- - "bus": AXI/register clock
+ - "bus": AXI/master interface clock
+ - "reg": AHB/slave interface clock
+ (only required if GPU can gate slave interface independently)
- "core": GPU core clock
- "shader": Shader clock (only required if GPU has feature PIPE_3D)
diff --git a/Documentation/devicetree/bindings/display/msm/dsi.txt b/Documentation/devicetree/bindings/display/msm/dsi.txt
index a6671bd2c85a..518e9cdf0d4b 100644
--- a/Documentation/devicetree/bindings/display/msm/dsi.txt
+++ b/Documentation/devicetree/bindings/display/msm/dsi.txt
@@ -7,8 +7,6 @@ Required properties:
- reg: Physical base address and length of the registers of controller
- reg-names: The names of register regions. The following regions are required:
* "dsi_ctrl"
-- qcom,dsi-host-index: The ID of DSI controller hardware instance. This should
- be 0 or 1, since we have 2 DSI controllers at most for now.
- interrupts: The interrupt signal from the DSI block.
- power-domains: Should be <&mmcc MDSS_GDSC>.
- clocks: Phandles to device clocks.
@@ -22,6 +20,8 @@ Required properties:
* "core"
For DSIv2, we need an additional clock:
* "src"
+ For DSI6G v2.0 onwards, we need also need the clock:
+ * "byte_intf"
- assigned-clocks: Parents of "byte" and "pixel" for the given platform.
- assigned-clock-parents: The Byte clock and Pixel clock PLL outputs provided
by a DSI PHY block. See [1] for details on clock bindings.
@@ -88,21 +88,35 @@ Required properties:
* "qcom,dsi-phy-28nm-lp"
* "qcom,dsi-phy-20nm"
* "qcom,dsi-phy-28nm-8960"
-- reg: Physical base address and length of the registers of PLL, PHY and PHY
- regulator
+ * "qcom,dsi-phy-14nm"
+ * "qcom,dsi-phy-10nm"
+- reg: Physical base address and length of the registers of PLL, PHY. Some
+ revisions require the PHY regulator base address, whereas others require the
+ PHY lane base address. See below for each PHY revision.
- reg-names: The names of register regions. The following regions are required:
+ For DSI 28nm HPM/LP/8960 PHYs and 20nm PHY:
* "dsi_pll"
* "dsi_phy"
* "dsi_phy_regulator"
+ For DSI 14nm and 10nm PHYs:
+ * "dsi_pll"
+ * "dsi_phy"
+ * "dsi_phy_lane"
- clock-cells: Must be 1. The DSI PHY block acts as a clock provider, creating
2 clocks: A byte clock (index 0), and a pixel clock (index 1).
-- qcom,dsi-phy-index: The ID of DSI PHY hardware instance. This should
- be 0 or 1, since we have 2 DSI PHYs at most for now.
- power-domains: Should be <&mmcc MDSS_GDSC>.
- clocks: Phandles to device clocks. See [1] for details on clock bindings.
- clock-names: the following clocks are required:
* "iface"
+ For 28nm HPM/LP, 28nm 8960 PHYs:
+- vddio-supply: phandle to vdd-io regulator device node
+ For 20nm PHY:
- vddio-supply: phandle to vdd-io regulator device node
+- vcca-supply: phandle to vcca regulator device node
+ For 14nm PHY:
+- vcca-supply: phandle to vcca regulator device node
+ For 10nm PHY:
+- vdds-supply: phandle to vdds regulator device node
Optional properties:
- qcom,dsi-phy-regulator-ldo-mode: Boolean value indicating if the LDO mode PHY
diff --git a/Documentation/devicetree/bindings/display/panel/arm,versatile-tft-panel.txt b/Documentation/devicetree/bindings/display/panel/arm,versatile-tft-panel.txt
new file mode 100644
index 000000000000..248141c3c7e3
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/arm,versatile-tft-panel.txt
@@ -0,0 +1,31 @@
+ARM Versatile TFT Panels
+
+These panels are connected to the daughterboards found on the
+ARM Versatile reference designs.
+
+This device node must appear as a child to a "syscon"-compatible
+node.
+
+Required properties:
+- compatible: should be "arm,versatile-tft-panel"
+
+Required subnodes:
+- port: see display/panel/panel-common.txt, graph.txt
+
+
+Example:
+
+sysreg@0 {
+ compatible = "arm,versatile-sysreg", "syscon", "simple-mfd";
+ reg = <0x00000 0x1000>;
+
+ panel: display@0 {
+ compatible = "arm,versatile-tft-panel";
+
+ port {
+ panel_in: endpoint {
+ remote-endpoint = <&foo>;
+ };
+ };
+ };
+};
diff --git a/Documentation/devicetree/bindings/display/panel/auo,g104sn02.txt b/Documentation/devicetree/bindings/display/panel/auo,g104sn02.txt
new file mode 100644
index 000000000000..85626edf63e5
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/auo,g104sn02.txt
@@ -0,0 +1,12 @@
+AU Optronics Corporation 10.4" (800x600) color TFT LCD panel
+
+Required properties:
+- compatible: should be "auo,g104sn02"
+- power-supply: as specified in the base binding
+
+Optional properties:
+- backlight: as specified in the base binding
+- enable-gpios: as specified in the base binding
+
+This binding is compatible with the simple-panel binding, which is specified
+in simple-panel.txt in this directory.
diff --git a/Documentation/devicetree/bindings/display/panel/display-timing.txt b/Documentation/devicetree/bindings/display/panel/display-timing.txt
index 58fa3e48481d..78222ced1874 100644
--- a/Documentation/devicetree/bindings/display/panel/display-timing.txt
+++ b/Documentation/devicetree/bindings/display/panel/display-timing.txt
@@ -80,6 +80,11 @@ The parameters are defined as:
| | v | | |
+----------+-------------------------------------+----------+-------+
+Note: In addition to being used as subnode(s) of display-timings, the timing
+ subnode may also be used on its own. This is appropriate if only one mode
+ need be conveyed. In this case, the node should be named 'panel-timing'.
+
+
Example:
display-timings {
diff --git a/Documentation/devicetree/bindings/display/panel/koe,tx31d200vm0baa.txt b/Documentation/devicetree/bindings/display/panel/koe,tx31d200vm0baa.txt
new file mode 100644
index 000000000000..6a036ede3e28
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/koe,tx31d200vm0baa.txt
@@ -0,0 +1,25 @@
+Kaohsiung Opto-Electronics. TX31D200VM0BAA 12.3" HSXGA LVDS panel
+
+This binding is compatible with the simple-panel binding, which is specified
+in simple-panel.txt in this directory.
+
+Required properties:
+- compatible: should be "koe,tx31d200vm0baa"
+
+Optional properties:
+- backlight: phandle of the backlight device attached to the panel
+
+Optional nodes:
+- Video port for LVDS panel input.
+
+Example:
+ panel {
+ compatible = "koe,tx31d200vm0baa";
+ backlight = <&backlight_lvds>;
+
+ port {
+ panel_in: endpoint {
+ remote-endpoint = <&lvds0_out>;
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/display/panel/orisetech,otm8009a.txt b/Documentation/devicetree/bindings/display/panel/orisetech,otm8009a.txt
index 6862028e7b2e..203b03eefb68 100644
--- a/Documentation/devicetree/bindings/display/panel/orisetech,otm8009a.txt
+++ b/Documentation/devicetree/bindings/display/panel/orisetech,otm8009a.txt
@@ -9,6 +9,7 @@ Required properties:
Optional properties:
- reset-gpios: a GPIO spec for the reset pin (active low).
+ - power-supply: phandle of the regulator that provides the supply voltage.
Example:
&dsi {
@@ -17,5 +18,6 @@ Example:
compatible = "orisetech,otm8009a";
reg = <0>;
reset-gpios = <&gpioh 7 GPIO_ACTIVE_LOW>;
+ power-supply = <&v1v8>;
};
};
diff --git a/Documentation/devicetree/bindings/display/panel/raydium,rm68200.txt b/Documentation/devicetree/bindings/display/panel/raydium,rm68200.txt
new file mode 100644
index 000000000000..cbb79ef3bfc9
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/panel/raydium,rm68200.txt
@@ -0,0 +1,25 @@
+Raydium Semiconductor Corporation RM68200 5.5" 720p MIPI-DSI TFT LCD panel
+
+The Raydium Semiconductor Corporation RM68200 is a 5.5" 720x1280 TFT LCD
+panel connected using a MIPI-DSI video interface.
+
+Required properties:
+ - compatible: "raydium,rm68200"
+ - reg: the virtual channel number of a DSI peripheral
+
+Optional properties:
+ - reset-gpios: a GPIO spec for the reset pin (active low).
+ - power-supply: phandle of the regulator that provides the supply voltage.
+ - backlight: phandle of the backlight device attached to the panel.
+
+Example:
+&dsi {
+ ...
+ panel@0 {
+ compatible = "raydium,rm68200";
+ reg = <0>;
+ reset-gpios = <&gpiof 15 GPIO_ACTIVE_LOW>;
+ power-supply = <&v1v8>;
+ backlight = <&pwm_backlight>;
+ };
+};
diff --git a/Documentation/devicetree/bindings/display/panel/simple-panel.txt b/Documentation/devicetree/bindings/display/panel/simple-panel.txt
index 16d8ff088b7d..45a457ad38f0 100644
--- a/Documentation/devicetree/bindings/display/panel/simple-panel.txt
+++ b/Documentation/devicetree/bindings/display/panel/simple-panel.txt
@@ -1,4 +1,8 @@
Simple display panel
+====================
+
+panel node
+----------
Required properties:
- power-supply: See panel-common.txt
diff --git a/Documentation/devicetree/bindings/display/renesas,du.txt b/Documentation/devicetree/bindings/display/renesas,du.txt
index cd48aba3bc8c..c9cd17f99702 100644
--- a/Documentation/devicetree/bindings/display/renesas,du.txt
+++ b/Documentation/devicetree/bindings/display/renesas,du.txt
@@ -13,13 +13,10 @@ Required Properties:
- "renesas,du-r8a7794" for R8A7794 (R-Car E2) compatible DU
- "renesas,du-r8a7795" for R8A7795 (R-Car H3) compatible DU
- "renesas,du-r8a7796" for R8A7796 (R-Car M3-W) compatible DU
+ - "renesas,du-r8a77970" for R8A77970 (R-Car V3M) compatible DU
+ - "renesas,du-r8a77995" for R8A77995 (R-Car D3) compatible DU
- - reg: A list of base address and length of each memory resource, one for
- each entry in the reg-names property.
- - reg-names: Name of the memory resources. The DU requires one memory
- resource for the DU core (named "du") and one memory resource for each
- LVDS encoder (named "lvds.x" with "x" being the LVDS controller numerical
- index).
+ - reg: the memory-mapped I/O registers base address and length
- interrupt-parent: phandle of the parent interrupt controller.
- interrupts: Interrupt specifiers for the DU interrupts.
@@ -29,14 +26,13 @@ Required Properties:
- clock-names: Name of the clocks. This property is model-dependent.
- R8A7779 uses a single functional clock. The clock doesn't need to be
named.
- - All other DU instances use one functional clock per channel and one
- clock per LVDS encoder (if available). The functional clocks must be
- named "du.x" with "x" being the channel numerical index. The LVDS clocks
- must be named "lvds.x" with "x" being the LVDS encoder numerical index.
- - In addition to the functional and encoder clocks, all DU versions also
- support externally supplied pixel clocks. Those clocks are optional.
- When supplied they must be named "dclkin.x" with "x" being the input
- clock numerical index.
+ - All other DU instances use one functional clock per channel The
+ functional clocks must be named "du.x" with "x" being the channel
+ numerical index.
+ - In addition to the functional clocks, all DU versions also support
+ externally supplied pixel clocks. Those clocks are optional. When
+ supplied they must be named "dclkin.x" with "x" being the input clock
+ numerical index.
- vsps: A list of phandle and channel index tuples to the VSPs that handle
the memory interfaces for the DU channels. The phandle identifies the VSP
@@ -63,15 +59,15 @@ corresponding to each DU output.
R8A7794 (R-Car E2) DPAD 0 DPAD 1 - -
R8A7795 (R-Car H3) DPAD 0 HDMI 0 HDMI 1 LVDS 0
R8A7796 (R-Car M3-W) DPAD 0 HDMI 0 LVDS 0 -
+ R8A77970 (R-Car V3M) DPAD 0 LVDS 0 - -
+ R8A77995 (R-Car D3) DPAD 0 LVDS 0 LVDS 1 -
Example: R8A7795 (R-Car H3) ES2.0 DU
du: display@feb00000 {
compatible = "renesas,du-r8a7795";
- reg = <0 0xfeb00000 0 0x80000>,
- <0 0xfeb90000 0 0x14>;
- reg-names = "du", "lvds.0";
+ reg = <0 0xfeb00000 0 0x80000>;
interrupts = <GIC_SPI 256 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 268 IRQ_TYPE_LEVEL_HIGH>,
<GIC_SPI 269 IRQ_TYPE_LEVEL_HIGH>,
@@ -79,9 +75,8 @@ Example: R8A7795 (R-Car H3) ES2.0 DU
clocks = <&cpg CPG_MOD 724>,
<&cpg CPG_MOD 723>,
<&cpg CPG_MOD 722>,
- <&cpg CPG_MOD 721>,
- <&cpg CPG_MOD 727>;
- clock-names = "du.0", "du.1", "du.2", "du.3", "lvds.0";
+ <&cpg CPG_MOD 721>;
+ clock-names = "du.0", "du.1", "du.2", "du.3";
vsps = <&vspd0 0>, <&vspd1 0>, <&vspd2 0>, <&vspd0 1>;
ports {
diff --git a/Documentation/devicetree/bindings/display/rockchip/cdn-dp-rockchip.txt b/Documentation/devicetree/bindings/display/rockchip/cdn-dp-rockchip.txt
new file mode 100644
index 000000000000..8df7d2e393d6
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/rockchip/cdn-dp-rockchip.txt
@@ -0,0 +1,74 @@
+Rockchip RK3399 specific extensions to the cdn Display Port
+================================
+
+Required properties:
+- compatible: must be "rockchip,rk3399-cdn-dp"
+
+- reg: physical base address of the controller and length
+
+- clocks: from common clock binding: handle to dp clock.
+
+- clock-names: from common clock binding:
+ Required elements: "core-clk" "pclk" "spdif" "grf"
+
+- resets : a list of phandle + reset specifier pairs
+- reset-names : string of reset names
+ Required elements: "apb", "core", "dptx", "spdif"
+- power-domains : power-domain property defined with a phandle
+ to respective power domain.
+- assigned-clocks: main clock, should be <&cru SCLK_DP_CORE>
+- assigned-clock-rates : the DP core clk frequency, shall be: 100000000
+
+- rockchip,grf: this soc should set GRF regs, so need get grf here.
+
+- ports: contain a port nodes with endpoint definitions as defined in
+ Documentation/devicetree/bindings/media/video-interfaces.txt.
+ contained 2 endpoints, connecting to the output of vop.
+
+- phys: from general PHY binding: the phandle for the PHY device.
+
+- extcon: extcon specifier for the Power Delivery
+
+- #sound-dai-cells = it must be 1 if your system is using 2 DAIs: I2S, SPDIF
+
+-------------------------------------------------------------------------------
+
+Example:
+ cdn_dp: dp@fec00000 {
+ compatible = "rockchip,rk3399-cdn-dp";
+ reg = <0x0 0xfec00000 0x0 0x100000>;
+ interrupts = <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&cru SCLK_DP_CORE>, <&cru PCLK_DP_CTRL>,
+ <&cru SCLK_SPDIF_REC_DPTX>, <&cru PCLK_VIO_GRF>;
+ clock-names = "core-clk", "pclk", "spdif", "grf";
+ assigned-clocks = <&cru SCLK_DP_CORE>;
+ assigned-clock-rates = <100000000>;
+ power-domains = <&power RK3399_PD_HDCP>;
+ phys = <&tcphy0_dp>, <&tcphy1_dp>;
+ resets = <&cru SRST_DPTX_SPDIF_REC>;
+ reset-names = "spdif";
+ extcon = <&fusb0>, <&fusb1>;
+ rockchip,grf = <&grf>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ #sound-dai-cells = <1>;
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ dp_in: port {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ dp_in_vopb: endpoint@0 {
+ reg = <0>;
+ remote-endpoint = <&vopb_out_dp>;
+ };
+
+ dp_in_vopl: endpoint@1 {
+ reg = <1>;
+ remote-endpoint = <&vopl_out_dp>;
+ };
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/display/st,stm32-ltdc.txt b/Documentation/devicetree/bindings/display/st,stm32-ltdc.txt
index 029252253ad4..3eb1b48b47dd 100644
--- a/Documentation/devicetree/bindings/display/st,stm32-ltdc.txt
+++ b/Documentation/devicetree/bindings/display/st,stm32-ltdc.txt
@@ -98,7 +98,7 @@ Example 2: DSI panel
compatible = "st,stm32-dsi";
reg = <0x40016c00 0x800>;
clocks = <&rcc 1 CLK_F469_DSI>, <&clk_hse>;
- clock-names = "ref", "pclk";
+ clock-names = "pclk", "ref";
resets = <&rcc STM32F4_APB2_RESET(DSI)>;
reset-names = "apb";
diff --git a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
index cd626ee1147a..3346c1e2a7a0 100644
--- a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
+++ b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
@@ -64,6 +64,56 @@ Required properties:
first port should be the input endpoint. The second should be the
output, usually to an HDMI connector.
+DWC HDMI TX Encoder
+-------------------
+
+The HDMI transmitter is a Synopsys DesignWare HDMI 1.4 TX controller IP
+with Allwinner's own PHY IP. It supports audio and video outputs and CEC.
+
+These DT bindings follow the Synopsys DWC HDMI TX bindings defined in
+Documentation/devicetree/bindings/display/bridge/dw_hdmi.txt with the
+following device-specific properties.
+
+Required properties:
+
+ - compatible: value must be one of:
+ * "allwinner,sun8i-a83t-dw-hdmi"
+ - reg: base address and size of memory-mapped region
+ - reg-io-width: See dw_hdmi.txt. Shall be 1.
+ - interrupts: HDMI interrupt number
+ - clocks: phandles to the clocks feeding the HDMI encoder
+ * iahb: the HDMI bus clock
+ * isfr: the HDMI register clock
+ * tmds: TMDS clock
+ - clock-names: the clock names mentioned above
+ - resets: phandle to the reset controller
+ - reset-names: must be "ctrl"
+ - phys: phandle to the DWC HDMI PHY
+ - phy-names: must be "phy"
+
+ - ports: A ports node with endpoint definitions as defined in
+ Documentation/devicetree/bindings/media/video-interfaces.txt. The
+ first port should be the input endpoint. The second should be the
+ output, usually to an HDMI connector.
+
+DWC HDMI PHY
+------------
+
+Required properties:
+ - compatible: value must be one of:
+ * allwinner,sun8i-a83t-hdmi-phy
+ * allwinner,sun8i-h3-hdmi-phy
+ - reg: base address and size of memory-mapped region
+ - clocks: phandles to the clocks feeding the HDMI PHY
+ * bus: the HDMI PHY interface clock
+ * mod: the HDMI PHY module clock
+ - clock-names: the clock names mentioned above
+ - resets: phandle to the reset controller driving the PHY
+ - reset-names: must be "phy"
+
+H3 HDMI PHY requires additional clock:
+ - pll-0: parent of phy clock
+
TV Encoder
----------
@@ -94,24 +144,29 @@ Required properties:
* allwinner,sun7i-a20-tcon
* allwinner,sun8i-a33-tcon
* allwinner,sun8i-a83t-tcon-lcd
+ * allwinner,sun8i-a83t-tcon-tv
* allwinner,sun8i-v3s-tcon
+ * allwinner,sun9i-a80-tcon-lcd
+ * allwinner,sun9i-a80-tcon-tv
- reg: base address and size of memory-mapped region
- interrupts: interrupt associated to this IP
- - clocks: phandles to the clocks feeding the TCON. Three are needed:
+ - clocks: phandles to the clocks feeding the TCON.
- 'ahb': the interface clocks
- - 'tcon-ch0': The clock driving the TCON channel 0
+ - 'tcon-ch0': The clock driving the TCON channel 0, if supported
- resets: phandles to the reset controllers driving the encoder
- - "lcd": the reset line for the TCON channel 0
+ - "lcd": the reset line for the TCON
+ - "edp": the reset line for the eDP block (A80 only)
- clock-names: the clock names mentioned above
- reset-names: the reset names mentioned above
- - clock-output-names: Name of the pixel clock created
+ - clock-output-names: Name of the pixel clock created, if TCON supports
+ channel 0.
- ports: A ports node with endpoint definitions as defined in
Documentation/devicetree/bindings/media/video-interfaces.txt. The
first port should be the input endpoint, the second one the output
- The output may have multiple endpoints. The TCON has two channels,
+ The output may have multiple endpoints. TCON can have 1 or 2 channels,
usually with the first channel being used for the panels interfaces
(RGB, LVDS, etc.), and the second being used for the outputs that
require another controller (TV Encoder, HDMI, etc.). The endpoints
@@ -119,11 +174,13 @@ Required properties:
channel the endpoint is associated to. If that property is not
present, the endpoint number will be used as the channel number.
-On SoCs other than the A33 and V3s, there is one more clock required:
+For TCONs with channel 0, there is one more clock required:
+ - 'tcon-ch0': The clock driving the TCON channel 0
+For TCONs with channel 1, there is one more clock required:
- 'tcon-ch1': The clock driving the TCON channel 1
-On SoCs that support LVDS (all SoCs but the A13, H3, H5 and V3s), you
-need one more reset line:
+When TCON support LVDS (all TCONs except TV TCON on A83T and those found
+in A13, H3, H5 and V3s SoCs), you need one more reset line:
- 'lvds': The reset line driving the LVDS logic
And on the A23, A31, A31s and A33, you need one more clock line:
@@ -134,7 +191,7 @@ DRC
---
The DRC (Dynamic Range Controller), found in the latest Allwinner SoCs
-(A31, A23, A33), allows to dynamically adjust pixel
+(A31, A23, A33, A80), allows to dynamically adjust pixel
brightness/contrast based on histogram measurements for LCD content
adaptive backlight control.
@@ -144,6 +201,7 @@ Required properties:
* allwinner,sun6i-a31-drc
* allwinner,sun6i-a31s-drc
* allwinner,sun8i-a33-drc
+ * allwinner,sun9i-a80-drc
- reg: base address and size of the memory-mapped region.
- interrupts: interrupt associated to this IP
- clocks: phandles to the clocks feeding the DRC
@@ -170,6 +228,7 @@ Required properties:
* allwinner,sun6i-a31-display-backend
* allwinner,sun7i-a20-display-backend
* allwinner,sun8i-a33-display-backend
+ * allwinner,sun9i-a80-display-backend
- reg: base address and size of the memory-mapped region.
- interrupts: interrupt associated to this IP
- clocks: phandles to the clocks feeding the frontend and backend
@@ -191,6 +250,28 @@ On the A33, some additional properties are required:
- resets and reset-names need to have a phandle to the SAT bus
resets, whose name will be "sat"
+DEU
+---
+
+The DEU (Detail Enhancement Unit), found in the Allwinner A80 SoC,
+can sharpen the display content in both luma and chroma channels.
+
+Required properties:
+ - compatible: value must be one of:
+ * allwinner,sun9i-a80-deu
+ - reg: base address and size of the memory-mapped region.
+ - interrupts: interrupt associated to this IP
+ - clocks: phandles to the clocks feeding the DEU
+ * ahb: the DEU interface clock
+ * mod: the DEU module clock
+ * ram: the DEU DRAM clock
+ - clock-names: the clock names mentioned above
+ - resets: phandles to the reset line driving the DEU
+
+- ports: A ports node with endpoint definitions as defined in
+ Documentation/devicetree/bindings/media/video-interfaces.txt. The
+ first port should be the input endpoints, the second one the outputs
+
Display Engine Frontend
-----------------------
@@ -204,6 +285,7 @@ Required properties:
* allwinner,sun6i-a31-display-frontend
* allwinner,sun7i-a20-display-frontend
* allwinner,sun8i-a33-display-frontend
+ * allwinner,sun9i-a80-display-frontend
- reg: base address and size of the memory-mapped region.
- interrupts: interrupt associated to this IP
- clocks: phandles to the clocks feeding the frontend and backend
@@ -226,6 +308,8 @@ supported.
Required properties:
- compatible: value must be one of:
* allwinner,sun8i-a83t-de2-mixer-0
+ * allwinner,sun8i-a83t-de2-mixer-1
+ * allwinner,sun8i-h3-de2-mixer-0
* allwinner,sun8i-v3s-de2-mixer
- reg: base address and size of the memory-mapped region.
- clocks: phandles to the clocks feeding the mixer
@@ -256,7 +340,9 @@ Required properties:
* allwinner,sun7i-a20-display-engine
* allwinner,sun8i-a33-display-engine
* allwinner,sun8i-a83t-display-engine
+ * allwinner,sun8i-h3-display-engine
* allwinner,sun8i-v3s-display-engine
+ * allwinner,sun9i-a80-display-engine
- allwinner,pipelines: list of phandle to the display engine
frontends (DE 1.0) or mixers (DE 2.0) available.
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index ae850d6c0ad3..12e8b3e576b0 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -104,6 +104,7 @@ eeti eGalax_eMPIA Technology Inc
elan Elan Microelectronic Corp.
embest Shenzhen Embest Technology Co., Ltd.
emmicro EM Microelectronic
+emtrion emtrion GmbH
energymicro Silicon Laboratories (formerly Energy Micro AS)
engicam Engicam S.r.l.
epcos EPCOS AG
diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.txt
index c4aa0adf13ec..5175a24d387e 100644
--- a/Documentation/devicetree/overlay-notes.txt
+++ b/Documentation/devicetree/overlay-notes.txt
@@ -87,8 +87,8 @@ Overlay in-kernel API
The API is quite easy to use.
-1. Call of_overlay_apply() to create and apply an overlay changeset. The return
-value is an error or a cookie identifying this overlay.
+1. Call of_overlay_fdt_apply() to create and apply an overlay changeset. The
+return value is an error or a cookie identifying this overlay.
2. Call of_overlay_remove() to remove and cleanup the overlay changeset
previously created via the call to of_overlay_apply(). Removal of an overlay
diff --git a/Documentation/features/list-arch.sh b/Documentation/features/list-arch.sh
index c16b5b595688..1ec47c3bb5fa 100755
--- a/Documentation/features/list-arch.sh
+++ b/Documentation/features/list-arch.sh
@@ -17,7 +17,7 @@ for F in */*/arch-support.txt; do
N=$(grep -h "^# Feature name:" $F | cut -c25-)
C=$(grep -h "^# Kconfig:" $F | cut -c25-)
D=$(grep -h "^# description:" $F | cut -c25-)
- S=$(grep -hw $ARCH $F | cut -d\| -f3)
+ S=$(grep -hv "^#" $F | grep -w $ARCH | cut -d\| -f3)
printf "%10s/%-22s:%s| %35s # %s\n" "$SUBSYS" "$N" "$S" "$C" "$D"
done
diff --git a/Documentation/gpu/drivers.rst b/Documentation/gpu/drivers.rst
new file mode 100644
index 000000000000..e8c84419a2a1
--- /dev/null
+++ b/Documentation/gpu/drivers.rst
@@ -0,0 +1,21 @@
+========================
+GPU Driver Documentation
+========================
+
+.. toctree::
+
+ i915
+ meson
+ pl111
+ tegra
+ tinydrm
+ tve200
+ vc4
+ bridge/dw-hdmi
+
+.. only:: subproject and html
+
+ Indices
+ =======
+
+ * :ref:`genindex`
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 2dcf5b42015d..1dffd1ac4cd4 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -286,6 +286,9 @@ Atomic Mode Setting Function Reference
.. kernel-doc:: drivers/gpu/drm/drm_atomic.c
:export:
+.. kernel-doc:: drivers/gpu/drm/drm_atomic.c
+ :internal:
+
CRTC Abstraction
================
@@ -547,8 +550,9 @@ Explicit Fencing Properties
Existing KMS Properties
-----------------------
-The following table gives description of drm properties exposed by
-various modules/drivers.
+The following table gives description of drm properties exposed by various
+modules/drivers. Because this table is very unwieldy, do not add any new
+properties here. Instead document them in a section above.
.. csv-table::
:header-rows: 1
diff --git a/Documentation/gpu/index.rst b/Documentation/gpu/index.rst
index c36586dad29d..00288f34c5a6 100644
--- a/Documentation/gpu/index.rst
+++ b/Documentation/gpu/index.rst
@@ -10,16 +10,9 @@ Linux GPU Driver Developer's Guide
drm-kms
drm-kms-helpers
drm-uapi
- i915
- meson
- pl111
- tegra
- tinydrm
- tve200
- vc4
+ drivers
vga-switcheroo
vgaarbiter
- bridge/dw-hdmi
todo
.. only:: subproject and html
diff --git a/Documentation/gpu/kms-properties.csv b/Documentation/gpu/kms-properties.csv
index 927b65e14219..6b28b014cb7d 100644
--- a/Documentation/gpu/kms-properties.csv
+++ b/Documentation/gpu/kms-properties.csv
@@ -1,5 +1,4 @@
Owner Module/Drivers,Group,Property Name,Type,Property Values,Object attached,Description/Restrictions
-,,“scaling mode”,ENUM,"{ ""None"", ""Full"", ""Center"", ""Full aspect"" }",Connector,"Supported by: amdgpu, gma500, i915, nouveau and radeon."
,DVI-I,“subconnector”,ENUM,"{ “Unknown”, “DVI-D”, “DVI-A” }",Connector,TBD
,,“select subconnector”,ENUM,"{ “Automatic”, “DVI-D”, “DVI-A” }",Connector,TBD
,TV,“subconnector”,ENUM,"{ ""Unknown"", ""Composite"", ""SVIDEO"", ""Component"", ""SCART"" }",Connector,TBD
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 1e593370f64f..f4d0b3476d9c 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -212,6 +212,16 @@ probably use drm_fb_helper_fbdev_teardown().
Contact: Maintainer of the driver you plan to convert
+idr_init_base()
+---------------
+
+DRM core&drivers uses a lot of idr (integer lookup directories) for mapping
+userspace IDs to internal objects, and in most places ID=0 means NULL and hence
+is never used. Switching to idr_init_base() for these would make the idr more
+efficient.
+
+Contact: Daniel Vetter
+
Core refactorings
=================
@@ -440,5 +450,12 @@ See drivers/gpu/drm/amd/display/TODO for tasks.
Contact: Harry Wentland, Alex Deucher
+i915
+----
+
+- Our early/late pm callbacks could be removed in favour of using
+ device_link_add to model the dependency between i915 and snd_had. See
+ https://dri.freedesktop.org/docs/drm/driver-api/device_link.html
+
Outside DRM
===========
diff --git a/Documentation/isdn/INTERFACE.CAPI b/Documentation/isdn/INTERFACE.CAPI
index 1688b5a1fd77..021aa9cf139d 100644
--- a/Documentation/isdn/INTERFACE.CAPI
+++ b/Documentation/isdn/INTERFACE.CAPI
@@ -18,7 +18,7 @@ corresponding hardware driver. Kernel CAPI then forwards CAPI messages in both
directions between the application and the hardware driver.
Format and semantics of CAPI messages are specified in the CAPI 2.0 standard.
-This standard is freely available from http://www.capi.org.
+This standard is freely available from https://www.capi.org.
2. Driver and Device Registration
diff --git a/Documentation/isdn/README b/Documentation/isdn/README
index 32d4e80c2c03..74bd2bdb455b 100644
--- a/Documentation/isdn/README
+++ b/Documentation/isdn/README
@@ -33,10 +33,10 @@ README for the ISDN-subsystem
de.alt.comm.isdn4linux
There is also a well maintained FAQ in English available at
- http://www.mhessler.de/i4lfaq/
+ https://www.mhessler.de/i4lfaq/
It can be viewed online, or downloaded in sgml/text/html format.
The FAQ can also be viewed online at
- http://www.isdn4linux.de/faq/
+ https://www.isdn4linux.de/faq/i4lfaq.html
or downloaded from
ftp://ftp.isdn4linux.de/pub/isdn4linux/FAQ/
diff --git a/Documentation/isdn/README.FAQ b/Documentation/isdn/README.FAQ
index 356f7944641d..e5dd1addacdd 100644
--- a/Documentation/isdn/README.FAQ
+++ b/Documentation/isdn/README.FAQ
@@ -8,9 +8,9 @@ You find it in:
In case you just want to see the FAQ online, or download the newest version,
you can have a look at my website:
-http://www.mhessler.de/i4lfaq/ (view + download)
+https://www.mhessler.de/i4lfaq/ (view + download)
or:
-http://www.isdn4linux.de/faq/ (view)
+https://www.isdn4linux.de/faq/4lfaq.html (view)
As the extension tells, the FAQ is in SGML format, and you can convert it
into text/html/... format by using the sgml2txt/sgml2html/... tools.
diff --git a/Documentation/isdn/README.gigaset b/Documentation/isdn/README.gigaset
index 7534c6039adc..9b1ce277ca3d 100644
--- a/Documentation/isdn/README.gigaset
+++ b/Documentation/isdn/README.gigaset
@@ -29,8 +29,9 @@ GigaSet 307x Device Driver
T-Com Sinus 721 data
Chicago 390 USB (KPN)
- See also http://www.erbze.info/sinus_gigaset.htm and
- http://gigaset307x.sourceforge.net/
+ See also http://www.erbze.info/sinus_gigaset.htm
+ (archived at https://web.archive.org/web/20100717020421/http://www.erbze.info:80/sinus_gigaset.htm ) and
+ http://gigaset307x.sourceforge.net/
We had also reports from users of Gigaset M105 who could use the drivers
with SX 100 and CX 100 ISDN bases (only in unimodem mode, see section 2.5.)
@@ -52,7 +53,7 @@ GigaSet 307x Device Driver
to use CAPI 2.0 or ISDN4Linux for ISDN connections (voice or data).
There are some user space tools available at
- http://sourceforge.net/projects/gigaset307x/
+ https://sourceforge.net/projects/gigaset307x/
which provide access to additional device specific functions like SMS,
phonebook or call journal.
@@ -202,7 +203,7 @@ GigaSet 307x Device Driver
You can use some configuration tool of your distribution to configure this
"modem" or configure pppd/wvdial manually. There are some example ppp
configuration files and chat scripts in the gigaset-VERSION/ppp directory
- in the driver packages from http://sourceforge.net/projects/gigaset307x/.
+ in the driver packages from https://sourceforge.net/projects/gigaset307x/.
Please note that the USB drivers are not able to change the state of the
control lines. This means you must use "Stupid Mode" if you are using
wvdial or you should use the nocrtscts option of pppd.
@@ -361,7 +362,7 @@ GigaSet 307x Device Driver
---------------------------
If you can't solve problems with the driver on your own, feel free to
use one of the forums, bug trackers, or mailing lists on
- http://sourceforge.net/projects/gigaset307x
+ https://sourceforge.net/projects/gigaset307x
or write an electronic mail to the maintainers.
Try to provide as much information as possible, such as
@@ -391,11 +392,12 @@ GigaSet 307x Device Driver
4. Links, other software
---------------------
- Sourceforge project developing this driver and associated tools
- http://sourceforge.net/projects/gigaset307x
+ https://sourceforge.net/projects/gigaset307x
- Yahoo! Group on the Siemens Gigaset family of devices
- http://de.groups.yahoo.com/group/Siemens-Gigaset
+ https://de.groups.yahoo.com/group/Siemens-Gigaset
- Siemens Gigaset/T-Sinus compatibility table
http://www.erbze.info/sinus_gigaset.htm
+ (archived at https://web.archive.org/web/20100717020421/http://www.erbze.info:80/sinus_gigaset.htm )
5. Credits
diff --git a/Documentation/locking/lockdep-design.txt b/Documentation/locking/lockdep-design.txt
index 9de1c158d44c..49f58a07ee7b 100644
--- a/Documentation/locking/lockdep-design.txt
+++ b/Documentation/locking/lockdep-design.txt
@@ -27,7 +27,8 @@ lock-class.
State
-----
-The validator tracks lock-class usage history into 4n + 1 separate state bits:
+The validator tracks lock-class usage history into 4 * nSTATEs + 1 separate
+state bits:
- 'ever held in STATE context'
- 'ever held as readlock in STATE context'
@@ -37,7 +38,6 @@ The validator tracks lock-class usage history into 4n + 1 separate state bits:
Where STATE can be either one of (kernel/locking/lockdep_states.h)
- hardirq
- softirq
- - reclaim_fs
- 'ever used' [ == !unused ]
@@ -169,6 +169,53 @@ Note: When changing code to use the _nested() primitives, be careful and
check really thoroughly that the hierarchy is correctly mapped; otherwise
you can get false positives or false negatives.
+Annotations
+-----------
+
+Two constructs can be used to annotate and check where and if certain locks
+must be held: lockdep_assert_held*(&lock) and lockdep_*pin_lock(&lock).
+
+As the name suggests, lockdep_assert_held* family of macros assert that a
+particular lock is held at a certain time (and generate a WARN() otherwise).
+This annotation is largely used all over the kernel, e.g. kernel/sched/
+core.c
+
+ void update_rq_clock(struct rq *rq)
+ {
+ s64 delta;
+
+ lockdep_assert_held(&rq->lock);
+ [...]
+ }
+
+where holding rq->lock is required to safely update a rq's clock.
+
+The other family of macros is lockdep_*pin_lock(), which is admittedly only
+used for rq->lock ATM. Despite their limited adoption these annotations
+generate a WARN() if the lock of interest is "accidentally" unlocked. This turns
+out to be especially helpful to debug code with callbacks, where an upper
+layer assumes a lock remains taken, but a lower layer thinks it can maybe drop
+and reacquire the lock ("unwittingly" introducing races). lockdep_pin_lock()
+returns a 'struct pin_cookie' that is then used by lockdep_unpin_lock() to check
+that nobody tampered with the lock, e.g. kernel/sched/sched.h
+
+ static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
+ {
+ rf->cookie = lockdep_pin_lock(&rq->lock);
+ [...]
+ }
+
+ static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf)
+ {
+ [...]
+ lockdep_unpin_lock(&rq->lock, rf->cookie);
+ }
+
+While comments about locking requirements might provide useful information,
+the runtime checks performed by annotations are invaluable when debugging
+locking problems and they carry the same level of details when inspecting
+code. Always prefer annotations when in doubt!
+
Proof of 100% correctness:
--------------------------
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index a863009849a3..6dafc8085acc 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -14,7 +14,11 @@ DISCLAIMER
This document is not a specification; it is intentionally (for the sake of
brevity) and unintentionally (due to being human) incomplete. This document is
meant as a guide to using the various memory barriers provided by Linux, but
-in case of any doubt (and there are many) please ask.
+in case of any doubt (and there are many) please ask. Some doubts may be
+resolved by referring to the formal memory consistency model and related
+documentation at tools/memory-model/. Nevertheless, even this memory
+model should be viewed as the collective opinion of its maintainers rather
+than as an infallible oracle.
To repeat, this document is not a specification of what Linux expects from
hardware.
@@ -48,7 +52,7 @@ CONTENTS
- Varieties of memory barrier.
- What may not be assumed about memory barriers?
- - Data dependency barriers.
+ - Data dependency barriers (historical).
- Control dependencies.
- SMP barrier pairing.
- Examples of memory barrier sequences.
@@ -399,7 +403,7 @@ Memory barriers come in four basic varieties:
where two loads are performed such that the second depends on the result
of the first (eg: the first load retrieves the address to which the second
load will be directed), a data dependency barrier would be required to
- make sure that the target of the second load is updated before the address
+ make sure that the target of the second load is updated after the address
obtained by the first load is accessed.
A data dependency barrier is a partial ordering on interdependent loads
@@ -550,8 +554,15 @@ There are certain things that the Linux kernel memory barriers do not guarantee:
Documentation/DMA-API.txt
-DATA DEPENDENCY BARRIERS
-------------------------
+DATA DEPENDENCY BARRIERS (HISTORICAL)
+-------------------------------------
+
+As of v4.15 of the Linux kernel, an smp_read_barrier_depends() was
+added to READ_ONCE(), which means that about the only people who
+need to pay attention to this section are those working on DEC Alpha
+architecture-specific code and those working on READ_ONCE() itself.
+For those who need it, and for those who are interested in the history,
+here is the story of data-dependency barriers.
The usage requirements of data dependency barriers are a little subtle, and
it's not always obvious that they're needed. To illustrate, consider the
@@ -2839,8 +2850,9 @@ as that committed on CPU 1.
To intervene, we need to interpolate a data dependency barrier or a read
-barrier between the loads. This will force the cache to commit its coherency
-queue before processing any further requests:
+barrier between the loads (which as of v4.15 is supplied unconditionally
+by the READ_ONCE() macro). This will force the cache to commit its
+coherency queue before processing any further requests:
CPU 1 CPU 2 COMMENT
=============== =============== =======================================
@@ -2869,8 +2881,8 @@ Other CPUs may also have split caches, but must coordinate between the various
cachelets for normal memory accesses. The semantics of the Alpha removes the
need for hardware coordination in the absence of memory barriers, which
permitted Alpha to sport higher CPU clock rates back in the day. However,
-please note that smp_read_barrier_depends() should not be used except in
-Alpha arch-specific code and within the READ_ONCE() macro.
+please note that (again, as of v4.15) smp_read_barrier_depends() should not
+be used except in Alpha arch-specific code and within the READ_ONCE() macro.
CACHE COHERENCY VS DMA
@@ -3035,7 +3047,9 @@ the data dependency barrier really becomes necessary as this synchronises both
caches with the memory coherence system, thus making it seem like pointer
changes vs new data occur in the right order.
-The Alpha defines the Linux kernel's memory barrier model.
+The Alpha defines the Linux kernel's memory model, although as of v4.15
+the Linux kernel's addition of smp_read_barrier_depends() to READ_ONCE()
+greatly reduced Alpha's impact on the memory model.
See the subsection on "Cache Coherency" above.
diff --git a/Documentation/timers/NO_HZ.txt b/Documentation/timers/NO_HZ.txt
index 2dcaf9adb7a7..9591092da5e0 100644
--- a/Documentation/timers/NO_HZ.txt
+++ b/Documentation/timers/NO_HZ.txt
@@ -131,13 +131,6 @@ error message, and the boot CPU will be removed from the mask. Note that
this means that your system must have at least two CPUs in order for
CONFIG_NO_HZ_FULL=y to do anything for you.
-Alternatively, the CONFIG_NO_HZ_FULL_ALL=y Kconfig parameter specifies
-that all CPUs other than the boot CPU are adaptive-ticks CPUs. This
-Kconfig parameter will be overridden by the "nohz_full=" boot parameter,
-so that if both the CONFIG_NO_HZ_FULL_ALL=y Kconfig parameter and
-the "nohz_full=1" boot parameter is specified, the boot parameter will
-prevail so that only CPU 1 will be an adaptive-ticks CPU.
-
Finally, adaptive-ticks CPUs must have their RCU callbacks offloaded.
This is covered in the "RCU IMPLICATIONS" section below.