linux-kernel - Re: [PATCH] remoteproc: k3-r5: Fix driver shutdown

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Message-ID: <7ffe0f80-d4a2-4d6f-8c45-5a407ac2e584@siemens.com>
Date: Tue, 20 Aug 2024 16:20:34 +0200
From: Jan Kiszka <jan.kiszka@...mens.com>
To: Beleswar Prasad Padhi <b-padhi@...com>,
 Bjorn Andersson <andersson@...nel.org>,
 Mathieu Poirier <mathieu.poirier@...aro.org>,
 linux-remoteproc@...r.kernel.org
Cc: Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
 Apurva Nandan <a-nandan@...com>,
 "stable@...r.kernel.org" <stable@...r.kernel.org>, Nishanth Menon <nm@...com>
Subject: Re: [PATCH] remoteproc: k3-r5: Fix driver shutdown

On 20.08.24 11:48, Beleswar Prasad Padhi wrote:
> 
> On 20-08-2024 15:09, Jan Kiszka wrote:
>> On 20.08.24 11:30, Beleswar Prasad Padhi wrote:
>>> Hi Jan,
>>>
>>> On 19-08-2024 22:17, Jan Kiszka wrote:
>>>> From: Jan Kiszka <jan.kiszka@...mens.com>
>>>>
>>>> When k3_r5_cluster_rproc_exit is run, core 1 is shutdown and removed
>>>> first. When core 0 should then be stopped before its removal, it will
>>>> find core1->rproc as NULL already and crashes. Happens on rmmod e.g.
>>>
>>> Did you check this on top of -next-20240820 tag? There was a series[0]
>>> which was merged recently which fixed this condition. I don't see this
>>> issue when trying on top of -next-20240820 tag.
>>> [0]:
>>> https://lore.kernel.org/all/20240808074127.2688131-1-b-padhi@ti.com/
>>>
>> I didn't try those yet, I was on 6.11-rcX. But from reading them
>> quickly, I'm not seeing the two issues I found directly addressed there.
> 
> Check the comment by Andrew Davis[0], that addresses the above issue.
> 
> [0]:
> https://lore.kernel.org/all/0bba5293-a55d-4f13-887c-272a54d6e1ca@ti.com/
> 

OK, then someone still needs to update his patch accordingly.

>>
>>>> Fixes: 3c8a9066d584 ("remoteproc: k3-r5: Do not allow core1 to power
>>>> up before core0 via sysfs")
>>>> CC: stable@...r.kernel.org
>>>> Signed-off-by: Jan Kiszka <jan.kiszka@...mens.com>
>>>> ---
>>>>
>>>> There might be one more because I can still make this driver crash
>>>> after an operator error. Were error scenarios tested at all?
>>>
>>> Can you point out what is this issue more specifically, and I can take
>>> this up then.
>> Try starting core1 before core0, and then again - system will hang or
> If you are trying to stop and then start the cores from sysfs, that is
> not yet supported. The hang is thus expected.

What? Then the driver is broken, even more. Why wasn't it fully implemented?

Jan

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