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.or... 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;