On Fri, Apr 27, 2018 at 5:00 AM, Nicolai Hähnle <nhaeh...@gmail.com> wrote:
> On 26.04.2018 04:30, Marek Olšák wrote: > >> On Wed, Apr 25, 2018 at 6:56 PM, Gurchetan Singh < >> gurchetansi...@chromium.org <mailto:gurchetansi...@chromium.org>> wrote: >> >> On Wed, Apr 25, 2018 at 2:16 PM, Marek Olšák <mar...@gmail.com >> <mailto:mar...@gmail.com>> wrote: >> > From: Nicolai Hähnle <nicolai.haeh...@amd.com <mailto: >> nicolai.haeh...@amd.com>> >> > >> > Allow the caller to specify the row stride (in bytes) with which an >> image >> > should be mapped. Note that completely ignoring USER_STRIDE is a >> valid >> > implementation of mapImage. >> > >> > This is horrible API design. Unfortunately, cros_gralloc does >> indeed have >> > a horrible API design -- in that arbitrary images should be allowed >> to be >> > mapped with the stride that a linear image of the same width would >> have. >> >> Yes, unfortunately the gralloc API doesn't return the stride when >> (*lock) is called. However, the stride is returned during (*alloc). >> Currently, for the dri backend, minigbm uses >> __DRI_IMAGE_ATTRIB_STRIDE to compute the pixel stride given to >> Android. >> >> Is AMD seeing problems with the current approach (I haven't seen any >> bugs filed for this issue)? >> >> Another possible solution is to call mapImage()/unmapImage right after >> allocating the image, and use the stride returned by mapImage() to >> compute the pixel stride. That could also fix whatever bugs AMD is >> seeing. >> >> >> Thanks. You cleared it up to me. It looks like that everything we've been >> told so far is BS. This series isn't needed. >> >> The solution is to do this in the amdgpu minigbm backend at alloc time: >> stride = align(width * Bpp, 64); >> >> Later chips should change that to: >> stride = align(width * Bpp, 256); >> >> No querying needed. What do you think? >> > > I don't see how this approach can possibly work unless we always map the > whole texture. > Even if ChromeOS doesn't map the whole texture, we still need the stride change, because the hw can't use the display stride for mappings (it's an unsupported user stride). Marek
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
