Messages in this thread Patch in this message | | | From | John Stultz <> | Subject | [PATCH 07/15] ARM: etm: Return the entire trace buffer if it is empty after reset | Date | Wed, 20 Jun 2012 18:47:39 -0400 |
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From: Arve Hjønnevåg <arve@android.com>
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.
CC: Russell King <linux@arm.linux.org.uk> CC: Paul Gortmaker <paul.gortmaker@windriver.com> CC: Alexander Shishkin <alexander.shishkin@linux.intel.com> Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org> --- arch/arm/kernel/etm.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c index 3d21cf6..74444e5 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); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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