diff options
| author | Per Forlin <per.forlin@stericsson.com> | 2011-10-04 21:51:13 +0200 |
|---|---|---|
| committer | Robert Marklund <robert.marklund@stericsson.com> | 2011-10-27 16:08:34 +0200 |
| commit | 9a83612d9ecaed99fb658866b33bf39da4f962b0 (patch) | |
| tree | d591411177863f7a1f511f70ffbce81e5b81a68d | |
| parent | fb5d78ebe2b2274308ad77eddb664a503de95dbc (diff) | |
ux500: pm: prevent sleep during high wlan load
The system wake up latency from sleep adds an extra
overhead when running wlan in DMA mode. This
is not the case for PIO since the CPU usage
prevents the system from going to sleep.
ST-Ericsson ID: 357764
ST-Ericsson FOSS-OUT ID: Trivial
ST-Ericsson Linux next: NA
Change-Id: Ib3ac10da61ca9f3d9db4956a29fb694bd2c416cc
Signed-off-by: Per Forlin <per.forlin@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/33008
Reviewed-by: QABUILD
Reviewed-by: Johan RUDHOLM <johan.rudholm@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
| -rw-r--r-- | arch/arm/mach-ux500/pm/performance.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/arch/arm/mach-ux500/pm/performance.c b/arch/arm/mach-ux500/pm/performance.c index 4f9fe381fd9..e919e01614c 100644 --- a/arch/arm/mach-ux500/pm/performance.c +++ b/arch/arm/mach-ux500/pm/performance.c @@ -16,6 +16,7 @@ #include <linux/kernel.h> #include <linux/mfd/dbx500-prcmu.h> #include <linux/cpu.h> +#include <linux/pm_qos_params.h> #include <mach/irqs.h> @@ -47,6 +48,8 @@ static struct delayed_work work_mmc; static struct delayed_work work_wlan_workaround; +static struct pm_qos_request_list wlan_pm_qos_latency; +static bool wlan_pm_qos_is_latency_0; static void wlan_load(struct work_struct *work) { @@ -58,12 +61,31 @@ static void wlan_load(struct work_struct *work) num_irqs += kstat_irqs_cpu(IRQ_DB8500_SDMMC1, cpu); if ((num_irqs > old_num_irqs) && - (num_irqs - old_num_irqs) > WLAN_LIMIT) + (num_irqs - old_num_irqs) > WLAN_LIMIT) { prcmu_qos_update_requirement(PRCMU_QOS_ARM_OPP, "wlan", 125); - else + if (!wlan_pm_qos_is_latency_0) { + /* + * The wake up latency is set to 0 to prevent + * the system from going to sleep. This improves + * the wlan throughput in DMA mode. + * The wake up latency from sleep adds ~5% overhead + * for TX in some cases. + * This change doesn't increase performance for wlan + * PIO since the CPU usage prevents sleep in this mode. + */ + pm_qos_add_request(&wlan_pm_qos_latency, + PM_QOS_CPU_DMA_LATENCY, 0); + wlan_pm_qos_is_latency_0 = true; + } + } else { prcmu_qos_update_requirement(PRCMU_QOS_ARM_OPP, "wlan", 25); + if (wlan_pm_qos_is_latency_0) { + pm_qos_remove_request(&wlan_pm_qos_latency); + wlan_pm_qos_is_latency_0 = false; + } + } old_num_irqs = num_irqs; |