Hi Suzuki,
On 2020-10-16 18:45, Suzuki Poulose wrote:
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.
Sure I will check again.
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
Thanks. One more thing, does the internal erratum number (if it exists) is good enough to be documented in the Documentation/arm64/silicon-errata.rst ? I ask this because outside qualcomm, it won't mean much right.
Thanks, Sai