[Spice-devel] [PATCH v1 1/6] dma-buf: Add _unlocked postfix to function names

Christian König christian.koenig at amd.com
Fri Jul 15 11:04:21 UTC 2022


Am 15.07.22 um 11:31 schrieb Dmitry Osipenko:
> On 7/15/22 10:19, Christian König wrote:
>>> -struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment
>>> *attach,
>>> -                    enum dma_data_direction direction)
>>> +struct sg_table *
>>> +dma_buf_map_attachment_unlocked(struct dma_buf_attachment *attach,
>>> +                enum dma_data_direction direction)
>> The locking state of mapping and unmapping operations depend on if the
>> attachment is dynamic or not.
>>
>> So this here is not a good idea at all since it suggests that the
>> function is always called without holding the lock.
> I had the same thought while was working on this patch and initially was
> thinking about adding an "unlocked" alias to dma_buf_map_attachment().
> In the end I decided that it will create even more confusion and it's
> simpler just to rename this func here since there are only two drivers
> using the dynamic mapping.
>
> Do you have suggestions how to improve it?

Just keep it as it is. The ultimative goal is to switch all drivers over 
to the dynamic mapping or at least over to assume that the map/unmap 
callbacks are called with the lock held.

Regards,
Christian.


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