Re: [PATCH v2 16/37] drm/i915/lmem: support pread

Matthew Auld
2019-07-30T09:25:31Z

On 30/07/2019 09:58, Daniel Vetter wrote:
> On Thu, Jun 27, 2019 at 09:56:12PM +0100, Matthew Auld wrote:
>> We need to add support for pread'ing an LMEM object.
>
> Why? Usage outside from igts seems pretty dead, at least looking at iris
> and anv. This was kinda a neat thing for when we didn't yet realized that
> doing clflush in userspace is both possible and more efficient.
>
> Same for pwrite, iris just dropped it, anv doesn't seem to use it. And I
> thought mesa plan is to drop the old classic driver for when we'll need
> lmem. It's not much, but would allow us to drop a few things.

Hmm, it was at least useful in the super early days for debugging. If we
were to drop this what do we do with the igts? Just use mmap?