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SubjectRe: [PATCH v2] i2c: rk3x: fix potential spinlock recursion on poll
On 2023-12-07 10:25, Jensen Huang wrote:
> On Thu, Dec 7, 2023 at 4:37 PM Dragan Simic <dsimic@manjaro.org> wrote:
>>
>> On 2023-12-07 09:21, Jensen Huang wrote:
>> > Possible deadlock scenario (on reboot):
>> > rk3x_i2c_xfer_common(polling)
>> > -> rk3x_i2c_wait_xfer_poll()
>> > -> rk3x_i2c_irq(0, i2c);
>> > --> spin_lock(&i2c->lock);
>> > ...
>> > <rk3x i2c interrupt>
>> > -> rk3x_i2c_irq(0, i2c);
>> > --> spin_lock(&i2c->lock); (deadlock here)
>> >
>> > Store the IRQ number and disable/enable it around the polling transfer.
>> > This patch has been tested on NanoPC-T4.
>>
>> In case you haven't already seen the related discussion linked below,
>> please have a look. I also added more people to the list of
>> recipients,
>> in an attempt to make everyone aware of the different approaches to
>> solving this issue.
>>
>> https://lore.kernel.org/all/655177f4.050a0220.d85c9.3ba0@mx.google.com/T/#m6fc9c214452fec6681843e7f455978c35c6f6c8b
>
> Thank you for providing the information. I hadn't seen this link
> before.
> After carefully looking into the related discussion, it appears that
> Dmitry Osipenko is already working on a suitable patch. To avoid
> duplication
> or conflicts, my patch can be discarded.

Thank you for responding so quickly. Perhaps it would be best to hear
from Dmitry as well, before discarding anything. It's been a while
since Dmitry wrote about working on the patch, so he might have
abandoned it.

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