On 10/16/20 12:47 PM, Sai Prakash Ranjan wrote:
Hi Suzuki,
On 2020-10-16 16:51, Suzuki Poulose wrote:
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 )
No, afaik we don't have any erratum assigned to this bug.
Ok. Please double check, if there are any.
It was already present in downstream kernel and since we support these targets with the previous HW bug (qcom,skip-power-up) now in upstream, we would need this fix in upstream kernel as well.
I understand the need for the fix and we must fix it. I was looking to document this in the central place for errata's handled in the kernel. And I missed asking this question when the original patch was posted. So, thought of asking the question now anyways. Better late than never ;-)
Reviewed-by: Suzuki K Poulose suzuki.poulose@arm.com