Hi Sai,
On 10/16/20 11:10 AM, Sai Prakash Ranjan wrote:
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
The fix is fine by me. Btw, is there a hardware Erratum assigned for this ? It would be good to have the Erratum documented somewhere, preferrably ( Documentation/arm64/silicon-errata.rst )
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