From c191e3322006f811a55d772f5a08218c709c6dea 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] 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 file changed, 5 insertions(+) diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c index 798a07152965..20aee26b9550 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 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);