From 97aba2e59990d8d53343c36f79b5895039cf0e1b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= Date: Fri, 4 Feb 2011 22:38:14 -0800 Subject: [PATCH 272/696] ARM: etm: Return the entire trace buffer if it is empty after reset MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 --- 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 2dac2bd..037c5e1 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 __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); -- 1.7.1