| Message ID | 20230207105317.224277-1-jfalempe@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/ast: Fix start address computation | expand |
Hi Am 07.02.23 um 11:53 schrieb Jocelyn Falempe: > During the driver conversion to shmem, there is a missing page shift when > computing the start address in GPU memory. > This leads to graphic garbage when connecting to the remote BMC, depending > on the PCI start address. > > Tested on a sr645 affected by this bug. > > Fixes: f2fa5a99ca81 ("drm/ast: Convert ast to SHMEM") > Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com> > --- > drivers/gpu/drm/ast/ast_mode.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c > index c7443317c747..d75e4a7611b3 100644 > --- a/drivers/gpu/drm/ast/ast_mode.c > +++ b/drivers/gpu/drm/ast/ast_mode.c > @@ -714,7 +714,7 @@ static int ast_primary_plane_init(struct ast_private *ast) > struct ast_plane *ast_primary_plane = &ast->primary_plane; > struct drm_plane *primary_plane = &ast_primary_plane->base; > void __iomem *vaddr = ast->vram; > - u64 offset = ast->vram_base; > + u64 offset = ast->vram_base << PAGE_SHIFT; That can't be the problem, I think. vram_base is already an address. [1] In the old code, drm_gem_vram_pg_offset() returned a page index. So shifting it to the left here is most likely incorrect. Can you verify that the new offset is the same as the old one? Best regards Thomas [1] https://elixir.bootlin.com/linux/v6.2-rc7/source/drivers/gpu/drm/ast/ast_mm.c#L96 > unsigned long cursor_size = roundup(AST_HWC_SIZE + AST_HWC_SIGNATURE_SIZE, PAGE_SIZE); > unsigned long size = ast->vram_fb_available - cursor_size; > int ret;
On 07/02/2023 12:17, Thomas Zimmermann wrote: > Hi > > Am 07.02.23 um 11:53 schrieb Jocelyn Falempe: >> During the driver conversion to shmem, there is a missing page shift when >> computing the start address in GPU memory. >> This leads to graphic garbage when connecting to the remote BMC, >> depending >> on the PCI start address. >> >> Tested on a sr645 affected by this bug. >> >> Fixes: f2fa5a99ca81 ("drm/ast: Convert ast to SHMEM") >> Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com> >> --- >> drivers/gpu/drm/ast/ast_mode.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/ast/ast_mode.c >> b/drivers/gpu/drm/ast/ast_mode.c >> index c7443317c747..d75e4a7611b3 100644 >> --- a/drivers/gpu/drm/ast/ast_mode.c >> +++ b/drivers/gpu/drm/ast/ast_mode.c >> @@ -714,7 +714,7 @@ static int ast_primary_plane_init(struct >> ast_private *ast) >> struct ast_plane *ast_primary_plane = &ast->primary_plane; >> struct drm_plane *primary_plane = &ast_primary_plane->base; >> void __iomem *vaddr = ast->vram; >> - u64 offset = ast->vram_base; >> + u64 offset = ast->vram_base << PAGE_SHIFT; > > That can't be the problem, I think. vram_base is already an address. [1] > In the old code, drm_gem_vram_pg_offset() returned a page index. So > shifting it to the left here is most likely incorrect. > > Can you verify that the new offset is the same as the old one? Yes, I was also a bit unsure about this fix. In my case, with the old code: PCI base address is 0xce000000 with old code: start address (which is 24bits) was 0 with shmem code: start address is 0x800000 So the additional page shift makes it 0, which fixes the display. I was wondering if this start address is not an offset in the GPU memory, and in this case the primary plane offset should always be 0 ? Best regards, > > Best regards > Thomas > > [1] > https://elixir.bootlin.com/linux/v6.2-rc7/source/drivers/gpu/drm/ast/ast_mm.c#L96 > >> unsigned long cursor_size = roundup(AST_HWC_SIZE + >> AST_HWC_SIGNATURE_SIZE, PAGE_SIZE); >> unsigned long size = ast->vram_fb_available - cursor_size; >> int ret; >
On 07/02/2023 12:36, Jocelyn Falempe wrote: > On 07/02/2023 12:17, Thomas Zimmermann wrote: >> Hi >> > > I was wondering if this start address is not an offset in the GPU > memory, and in this case the primary plane offset should always be 0 ? I think it's the case, so I will send a v2 shortly. > > Best regards, > >> >> Best regards >> Thomas >> >> [1] >> https://elixir.bootlin.com/linux/v6.2-rc7/source/drivers/gpu/drm/ast/ast_mm.c#L96 >> >>> unsigned long cursor_size = roundup(AST_HWC_SIZE + >>> AST_HWC_SIGNATURE_SIZE, PAGE_SIZE); >>> unsigned long size = ast->vram_fb_available - cursor_size; >>> int ret; >> >
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index c7443317c747..d75e4a7611b3 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -714,7 +714,7 @@ static int ast_primary_plane_init(struct ast_private *ast) struct ast_plane *ast_primary_plane = &ast->primary_plane; struct drm_plane *primary_plane = &ast_primary_plane->base; void __iomem *vaddr = ast->vram; - u64 offset = ast->vram_base; + u64 offset = ast->vram_base << PAGE_SHIFT; unsigned long cursor_size = roundup(AST_HWC_SIZE + AST_HWC_SIGNATURE_SIZE, PAGE_SIZE); unsigned long size = ast->vram_fb_available - cursor_size; int ret;
During the driver conversion to shmem, there is a missing page shift when computing the start address in GPU memory. This leads to graphic garbage when connecting to the remote BMC, depending on the PCI start address. Tested on a sr645 affected by this bug. Fixes: f2fa5a99ca81 ("drm/ast: Convert ast to SHMEM") Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com> --- drivers/gpu/drm/ast/ast_mode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)