From: Robin Murphy <robin.murphy@arm.com>
To: Will Deacon <will@kernel.org>, Geoff Blake <blakgeof@amazon.com>,
linux-kernel@vger.kernel.org
Cc: catalin.marinas@arm.com, kernel-team@android.com,
linux-arm-kernel@lists.infradead.org,
Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH] perf/arm-cmn: Add shutdown routine
Date: Wed, 30 Nov 2022 12:28:17 +0000 [thread overview]
Message-ID: <c7acc1af-b97e-f9f7-4891-64bc9380a12e@arm.com> (raw)
In-Reply-To: <166973320082.112522.10687339610259452670.b4-ty@kernel.org>
On 2022-11-29 19:52, Will Deacon wrote:
> On Fri, 25 Nov 2022 17:01:53 -0600, Geoff Blake wrote:
>> The CMN driver does not gracefully handle all
>> restart cases, such as kexec. On a kexec if the
>> arm-cmn driver is in use it can be left in a state
>> with still active events that can cause spurious and/or
>> unhandled interrupts that appear as non-fatal kernel errors
>> like below, that can be confusing and misleading:
>>
>> [...]
>
> Applied to will (for-next/perf), thanks!
>
> [1/1] perf/arm-cmn: Add shutdown routine
> https://git.kernel.org/will/c/316f862a787c
Oh, if I'd seen this I'd have said the same thing as when asked about it
off-list, that it's needlessly overcomplicated and doesn't really solve
the problem anyway. If there's a need to be robust against spurious
interrupts then that needs to be done in the interrupt handler.
Even if we do think it's worth stopping the PMU on shutdown, as we do on
remove, that still only needs a single register write (per the current
remove implementation).
Thanks,
Robin.
_______________________________________________
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:[~2022-11-30 12:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-25 23:01 [PATCH] perf/arm-cmn: Add shutdown routine Geoff Blake
2022-11-29 19:52 ` Will Deacon
2022-11-30 12:28 ` Robin Murphy [this message]
2022-11-30 13:29 ` Will Deacon
-- strict thread matches above, loose matches on Subject: below --
2022-12-05 15:38 [PATCH 1/2] perf/arm-cmn: Cope with spurious IRQs better Geoff Blake
2022-12-15 18:00 ` [PATCH] perf/arm-cmn: Add shutdown routine Geoff Blake
2023-01-04 15:55 ` Geoff Blake
2023-01-19 15:30 ` Geoff Blake
2023-01-19 15:32 ` Robin Murphy
2023-01-19 17:10 ` Geoff Blake
2023-01-19 18:14 ` Will Deacon
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=c7acc1af-b97e-f9f7-4891-64bc9380a12e@arm.com \
--to=robin.murphy@arm.com \
--cc=blakgeof@amazon.com \
--cc=catalin.marinas@arm.com \
--cc=kernel-team@android.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=will@kernel.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