[PATCH libdrm 1/2] amdgpu: prevent an integer wraparound of cpu_map_count

[Marek Olšák]

On Tue, Oct 30, 2018, 11:49 AM Marek Olšák <maraeo at gmail.com> wrote:

>
>
> On Tue, Oct 30, 2018, 4:20 AM Michel Dänzer <michel at daenzer.net> wrote:
>
>> On 2018-10-29 10:15 p.m., Marek Olšák wrote:
>> > You and I discussed this extensively internally a while ago. It's
>> expected
>> > and correct behavior. Mesa doesn't unmap some buffers and never will.
>>
>> It doesn't need to keep mapping the same buffer over and over again
>> though, does it?
>>
>
> It doesnt map it again. It just doesnt unmap. So the next map call just
> returns the pointer. It's correct to stop the counter wraparound.
>

Mesa doesn't track whether a buffer is already mapped. Libdrm tracks that.
It's a feature of libdrm to return the same pointer and expect infinite
number of map calls.

Marek


> Marek
>
>
>>
>> --
>> Earthling Michel Dänzer               |               http://www.amd.com
>> Libre software enthusiast             |             Mesa and X developer
>>
>
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