> -----Original Message----- > From: Daniel Vetter <daniel@xxxxxxxx> > Sent: 2021/January/07, Thursday 12:33 PM > To: Koenig, Christian <Christian.Koenig@xxxxxxx> > Cc: Liu, Zhan <Zhan.Liu@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx; Cornij, > Nikola <Nikola.Cornij@xxxxxxx>; Wang, Chao-kai (Stylon) > <Stylon.Wang@xxxxxxx>; Wang, Chao-kai (Stylon) > <Stylon.Wang@xxxxxxx>; dri-devel@xxxxxxxxxxxxxxxxxxxxx; Kazlauskas, > Nicholas <Nicholas.Kazlauskas@xxxxxxx>; bas@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH v2] drm/amdgpu: Do not change amdgpu framebuffer > format during page flip > > On Sun, Jan 03, 2021 at 04:43:37PM +0100, Christian König wrote: > > Am 29.12.20 um 22:10 schrieb Zhan Liu: > > > [Why] > > > Driver cannot change amdgpu framebuffer (afb) format while doing > > > page flip. Force system doing so will cause ioctl error, and result > > > in breaking several functionalities including FreeSync. > > > > > > If afb format is forced to change during page flip, following > > > message will appear in dmesg.log: > > > > > > "[drm:drm_mode_page_flip_ioctl [drm]] Page flip is not allowed to > > > change frame buffer format." > > > > > > [How] > > > Do not change afb format while doing page flip. It is okay to check > > > whether afb format is valid here, however, forcing afb format change > > > shouldn't happen here. > > > > I don't think this we can do this. > > > > It is perfectly valid for a page flip to switch between linear and > > tiled formats on an I+A or A+A laptop. > > It is, but that's not the bug here. struct drm_framebuffer.format is supposed > to be invariant over the lifetime of a drm_fb object, you need to set it when > the fb is created and never change it afterwards. So the patch here isn't yet > the real deal. > > Also this means the implicit tiling information cannot be changed after a fb is > created for a given bo, but we've discussed this at length and that limitation > should be all ok. > -Daniel Thank you Christian and Daniel for the input! Bas recently submitted an alternative patch ([PATCH] drm: Check actual format for legacy pageflip.) which addresses the same issue, and his patch makes more sense to me, so I will abandon my patch in this case. Thanks, Zhan > > > > > Christian. > > > > > > > > Signed-off-by: Zhan Liu <zhan.liu@xxxxxxx> > > > --- > > > drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 3 ++- > > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > > > Thanks Nick and Bas. Here is my second patch for review. > > > > > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > > > index a638709e9c92..8a12e27ff4ec 100644 > > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > > > @@ -832,7 +832,8 @@ static int convert_tiling_flags_to_modifier(struct > amdgpu_framebuffer *afb) > > > if (!format_info) > > > return -EINVAL; > > > - afb->base.format = format_info; > > > + if (!afb->base.format) > > > + afb->base.format = format_info; > > > } > > > } > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@xxxxxxxxxxxxxxxxxxxxx > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flist > > s.freedesktop.org%2Fmailman%2Flistinfo%2Fdri- > devel&data=04%7C01%7C > > > zhan.liu%40amd.com%7Cda23e6e33a7e46dfc4e308d8b33242c8%7C3dd896 > 1fe4884e > > > 608e11a82d994e183d%7C0%7C0%7C637456375746425509%7CUnknown% > 7CTWFpbGZsb3 > > > d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0 > %3D%7 > > > C1000&sdata=5lCm4d6FHihfFHUf5mVym0O6lKmZHgR89%2F2Eqj2ojhg > %3D&r > > eserved=0 > > -- > Daniel Vetter > Software Engineer, Intel Corporation > https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fblog.ff > wll.ch%2F&data=04%7C01%7Czhan.liu%40amd.com%7Cda23e6e33a7e > 46dfc4e308d8b33242c8%7C3dd8961fe4884e608e11a82d994e183d%7C0%7 > C0%7C637456375746425509%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4 > wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&a > mp;sdata=44x858klbIcVeRtP%2BuJST2K3xuCLisjbfhV9rEQrzpA%3D&rese > rved=0 _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
