From mboxrd@z Thu Jan 1 00:00:00 1970 From: arve@android.com (=?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?=) Date: Mon, 14 Feb 2011 22:11:15 -0800 Subject: [PATCH 7/8] ARM: etm: Return the entire trace buffer if it is empty after reset In-Reply-To: <1296701663-12168-1-git-send-email-arve@android.com> References: <1296701663-12168-1-git-send-email-arve@android.com> Message-ID: <1297750276-12475-7-git-send-email-arve@android.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Signed-off-by: Arve Hj?nnev?g --- arch/arm/kernel/etm.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c index 8126beb..4ad1257 100644 --- a/arch/arm/kernel/etm.c +++ b/arch/arm/kernel/etm.c @@ -44,6 +44,7 @@ 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; @@ -105,6 +106,7 @@ 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); @@ -311,6 +313,8 @@ 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); @@ -385,6 +389,7 @@ static int __init etb_probe(struct amba_device *dev, struct amba_id *id) goto out_release; } + t->dump_initial_etb = true; amba_set_drvdata(dev, t); etb_unlock(t); -- 1.7.3.1