Re: [PATCH v2] media: verisilicon: Fix crash when probing encoder

From: Michael Tretter <m.tretter@pengutronix.de>
To: Linux regressions mailing list <regressions@lists.linux.dev>
Cc: Diederik de Haas <didi.debian@cknow.org>,
	Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>,
	Nicolas Dufresne <nicolas.dufresne@collabora.com>,
	Benjamin Gaignard <benjamin.gaignard@collabora.com>,
	p.zabel@pengutronix.de, mchehab@kernel.org,
	m.szyprowski@samsung.com, linux-media@vger.kernel.org,
	linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org,
	kernel@collabora.com, hverkuil-cisco@xs4all.nl,
	Pengutronix Kernel Team <kernel@pengutronix.de>
Subject: Re: [PATCH v2] media: verisilicon: Fix crash when probing encoder
Date: Tue, 23 May 2023 16:54:30 +0200	[thread overview]
Message-ID: <20230523145430.GB9943@pengutronix.de> (raw)
In-Reply-To: <5d871928-dcd5-3f27-e975-d1639525dad0@leemhuis.info>

On Tue, 23 May 2023 12:50:42 +0200, Linux regression tracking (Thorsten Leemhuis) wrote:
> CCing the Regression list and a bunch of other people that were CCed in
> threads that look related:

Thanks!

> 
> On 23.05.23 00:38, Diederik de Haas wrote:
> > On Monday, 22 May 2023 18:17:39 CEST Benjamin Gaignard wrote:
> >> Le 20/05/2023 à 00:34, Diederik de Haas a écrit :
> >>> On Thursday, 13 April 2023 21:52:50 CEST Nicolas Dufresne wrote:
> > [...]
> >>> When I booted into my 6.4-rc1 (but also rc2) kernel on my
> >>> Pine64 Quartz64 Model A, I noticed a crash which seems the same as
> >>> above, but I didn't have such a crash with my 6.3 kernel.
> >>> Searching for 'hantro' led me to this commit as the most likely culprit
> >>> but when I build a new 6.4-rcX kernel with this commit reverted,
> >>> I still had this crash.
> >>> Do you have suggestions which commit would then be the likely culprit?
> >>
> >> This patch fix the crash at boot time, revert it doesn't seem to be the
> >> solution. Maybe this proposal from Marek can help you ?
> >>
> >> https://patchwork.kernel.org/project/linux-media/patch/20230421104759.2236463-1-m.szyprowski@samsung.com/
> > 
> > That helped :) After applying that patch I no longer have the crash.
> > Thanks!
> 
> That regression fix is now a month old, but not yet merged afaics --
> guess due to Nicolas comment that wasn't addressed yet and likely
> requires a updated patch.

I agree with Nicolas comment on that patch and it needs to be updated.

> 
> Michael afaics a week ago posted a patch that to my *very limited
> understanding of things* (I hope I don't confuse matters here!) seems to
> address the same problem, but slightly differently:
> https://lore.kernel.org/all/20230516091209.3098262-1-m.tretter@pengutronix.de/

Correct, my patch addresses the same problem.

> 
> No reply yet.
> 
> That's all a bit unfortunate, as it's not how regression fixes should be
> dealt with -- and caused multiple people headaches that could have been
> avoided. :-/
> 
> But well, things happen. But it leads to the question:
> 
> How can we finally address the issue quickly now to ensure is doesn't
> cause headaches for even more people?
> 
> Marek, Michael, could you work on a patch together that we then get
> somewhat fast-tracked to Linus to avoid him getting even more unhappy
> about the state of things[1]?

Marek, if you have an updated patch, I will happily test and review it.
Otherwise, please take a look at my patch.

Michael