From: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
To: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: denik@chromium.org, Mathieu Poirier <mathieu.poirier@linaro.org>,
linux-arm-msm@vger.kernel.org, coresight@lists.linaro.org,
linux-kernel@vger.kernel.org, Stephen Boyd <swboyd@chromium.org>,
linux-arm-kernel@lists.infradead.org,
Mike Leach <mike.leach@linaro.org>
Subject: Re: [PATCH] coresight: etm4x: Skip setting LPOVERRIDE bit for qcom,skip-power-up
Date: Fri, 16 Oct 2020 19:10:07 +0530 [thread overview]
Message-ID: <85ade254494144efc20c8c7512828654@codeaurora.org> (raw)
In-Reply-To: <9e19d312-9de4-2ed8-75ca-c774b93bfe11@arm.com>
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
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member
of Code Aurora Forum, hosted by The Linux Foundation
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-10-16 13:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-16 10:10 [PATCH] coresight: etm4x: Skip setting LPOVERRIDE bit for qcom, skip-power-up Sai Prakash Ranjan
2020-10-16 11:21 ` [PATCH] coresight: etm4x: Skip setting LPOVERRIDE bit for qcom,skip-power-up Suzuki Poulose
2020-10-16 11:47 ` Sai Prakash Ranjan
2020-10-16 13:15 ` Suzuki Poulose
2020-10-16 13:40 ` Sai Prakash Ranjan [this message]
2020-10-16 16:31 ` Mathieu Poirier
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=85ade254494144efc20c8c7512828654@codeaurora.org \
--to=saiprakash.ranjan@codeaurora.org \
--cc=coresight@lists.linaro.org \
--cc=denik@chromium.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mathieu.poirier@linaro.org \
--cc=mike.leach@linaro.org \
--cc=suzuki.poulose@arm.com \
--cc=swboyd@chromium.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).