Messages in this thread | | | Subject | Re: [PATCH] coresight: etm4x: Skip setting LPOVERRIDE bit for qcom,skip-power-up | From | Suzuki Poulose <> | Date | Fri, 16 Oct 2020 14:15:58 +0100 |
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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>
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