[PATCH 5.10 19/40] coresight: etm4x: Skip setting LPOVERRIDE bit for qcom, skip-power-up

Greg Kroah-Hartman
2020-12-23T15:34:12Z

From: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>

commit ac0f82b1b4956e348a6b2de8104308144ffb6ef7 upstream.

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")
Cc: stable@vger.kernel.org
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20201127175256.1092685-2-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- 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 *in
* 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;