From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758320Ab2FTWsk (ORCPT ); Wed, 20 Jun 2012 18:48:40 -0400 Received: from e31.co.us.ibm.com ([32.97.110.149]:41373 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757876Ab2FTWse (ORCPT ); Wed, 20 Jun 2012 18:48:34 -0400 From: John Stultz To: LKML Cc: =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Russell King , Paul Gortmaker , Alexander Shishkin , 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 Message-Id: <1340232467-6023-8-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1340232467-6023-1-git-send-email-john.stultz@linaro.org> References: <1340232467-6023-1-git-send-email-john.stultz@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12062022-7282-0000-0000-00000A239039 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arve Hjønnevåg 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 CC: Paul Gortmaker CC: Alexander Shishkin Acked-by: Alexander Shishkin Signed-off-by: Arve Hjønnevåg Signed-off-by: John Stultz --- 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