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* [PATCH] coresight: etm4x: Skip setting LPOVERRIDE bit for qcom,skip-power-up
@ 2020-10-16 10:10 Sai Prakash Ranjan
  2020-10-16 11:21 ` Suzuki Poulose
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Sai Prakash Ranjan @ 2020-10-16 10:10 UTC (permalink / raw)
  To: Mathieu Poirier, Suzuki K Poulose, Mike Leach
  Cc: coresight, Stephen Boyd, denik, linux-arm-msm, linux-kernel,
	linux-arm-kernel, Sai Prakash Ranjan

There is a bug on the systems supporting to skip power up
(qcom,skip-power-up) where setting LPOVERRIDE bit(low-power
state override behaviour) will result in CPU hangs/lockups
even on the implementations which supports it. So skip
setting the LPOVERRIDE bit for such platforms.

Fixes: 02510a5aa78d ("coresight: etm4x: Add support to skip trace unit power up")
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
---
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index abd706b216ac..6096d7abf80d 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -779,7 +779,7 @@ static void etm4_init_arch_data(void *info)
 	 * LPOVERRIDE, bit[23] implementation supports
 	 * low-power state override
 	 */
-	if (BMVAL(etmidr5, 23, 23))
+	if (BMVAL(etmidr5, 23, 23) && (!drvdata->skip_power_up))
 		drvdata->lpoverride = true;
 	else
 		drvdata->lpoverride = false;

base-commit: 3477326277451000bc667dfcc4fd0774c039184c
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2020-12-29 20:18 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-10-16 10:10 [PATCH] coresight: etm4x: Skip setting LPOVERRIDE bit for qcom,skip-power-up Sai Prakash Ranjan
2020-10-16 11:21 ` Suzuki Poulose
2020-10-16 11:47   ` Sai Prakash Ranjan
2020-10-16 13:15     ` Suzuki Poulose
2020-10-16 13:40       ` Sai Prakash Ranjan
2020-10-16 16:31 ` Mathieu Poirier
2020-12-29 20:15 ` patchwork-bot+linux-arm-msm

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