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authorArve Hjønnevåg <arve@android.com>2011-02-04 22:38:14 -0800
committerColin Cross <ccross@android.com>2012-02-14 11:30:44 -0800
commit102804cc017edff355309758ed346fc9098f74bd (patch)
treedd068536120567bddc1fb7d4ed42555d695cce6c /arch
parent15de182469b60c343f3eb4a46ba34f2d24fd03d6 (diff)
ARM: etm: Return the entire trace buffer if it is empty after reset
On some SOCs the read and write pointer are reset when the chip resets, but the trace buffer content is preserved. If the status bits indicates that the buffer is empty and we have never started tracing, assume the buffer is full instead. This can be useful if the system rebooted from a watchdog reset. Change-Id: Iaf21c2c329c6059004ee1d38e3dfff66d7d28029 Signed-off-by: Arve Hjønnevåg <arve@android.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/kernel/etm.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c
index 3d21cf6affa..74444e5cb1b 100644
--- a/arch/arm/kernel/etm.c
+++ b/arch/arm/kernel/etm.c
@@ -45,6 +45,7 @@ struct tracectx {
unsigned long range_end;
unsigned long data_range_start;
unsigned long data_range_end;
+ bool dump_initial_etb;
struct device *dev;
struct clk *emu_clk;
struct mutex mutex;
@@ -106,6 +107,7 @@ static int trace_start(struct tracectx *t)
etb_unlock(t);
+ t->dump_initial_etb = false;
etb_writel(t, 0, ETBR_WRITEADDR);
etb_writel(t, 0, ETBR_FORMATTERCTRL);
etb_writel(t, 1, ETBR_CTRL);
@@ -312,6 +314,8 @@ static ssize_t etb_read(struct file *file, char __user *data,
etb_unlock(t);
total = etb_getdatalen(t);
+ if (total == 0 && t->dump_initial_etb)
+ total = t->etb_bufsz;
if (total == t->etb_bufsz)
first = etb_readl(t, ETBR_WRITEADDR);
@@ -386,6 +390,7 @@ static int __devinit etb_probe(struct amba_device *dev, const struct amba_id *id
goto out_release;
}
+ t->dump_initial_etb = true;
amba_set_drvdata(dev, t);
etb_unlock(t);