Re: [PATCH v1 5/7] Revert "drm: Assert held reservation lock for dma-buf mmapping"
From: Dmitry Osipenko
Date: Tue Apr 04 2023 - 20:33:47 EST
On 4/3/23 18:17, Christian König wrote:
> Am 02.04.23 um 18:48 schrieb Dmitry Osipenko:
>> Don't assert held dma-buf reservation lock on memory mapping of exported
>> buffer.
>>
>> We're going to change dma-buf mmap() locking policy such that exporters
>> will have to handle the lock. The previous locking policy caused deadlock
>> problem for DRM drivers in a case of self-imported dma-bufs, it's solved
>> by moving the lock down to exporters.
>
> I only checked the TTM code path and think that at least that one should
> work fine.
>
>> Fixes: 39ce25291871 ("drm: Assert held reservation lock for dma-buf
>> mmapping")
>
> This here is not really a "fix" for the previous patch. We just found
> that we didn't like the behavior and so reverted the original patch.
>
> A "Reverts..." comment in the commit message would be more appropriate I
> think.
Ack, will drop the fixes tag in v2. Thank you and Emil for the review.
--
Best regards,
Dmitry