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

[Nicolas Dufresne]

Hi Micheal,

Le mardi 23 mai 2023 à 16:54 +0200, Michael Tretter a écrit :
> 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.

Sorry, just got really busy and missed the second fix. From a hot fix stand
point, your patch seems a lot safer. It does not go as far, and probably does
not make the driver better, but considering we had such a slow response we need
to do something about it.

Ezequiel, will you be fine with the approach ?

> 
> > 
> > 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
>