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authorJocelyn Falempe <jfalempe@redhat.com>2023-02-09 10:44:17 +0100
committerJocelyn Falempe <jfalempe@redhat.com>2023-02-10 14:32:57 +0100
commit7484a5bc153e81a1740c06ce037fd55b7638335c (patch)
tree7aa0350eb9e9292b1b868899b299855f74e82051
parent3efc61d95259956db25347e2a9562c3e54546e20 (diff)
downloadlinux-7484a5bc153e81a1740c06ce037fd55b7638335c.tar.gz
drm/ast: Fix start address computation
During the driver conversion to shmem, the start address for the scanout buffer was set to the base PCI address. In most cases it works because only the lower 24bits are used, and due to alignment it was almost always 0. But on some unlucky hardware, it's not the case, and some uninitialized memory is displayed on the BMC. With shmem, the primary plane is always at offset 0 in GPU memory. * v2: rewrite the patch to set the offset to 0. (Thomas Zimmermann) * v3: move the change to plane_init() and also fix the cursor plane. (Jammy Huang) Tested on a sr645 affected by this bug. Fixes: f2fa5a99ca81 ("drm/ast: Convert ast to SHMEM") Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Jammy Huang <jammy_huang@aspeedtech.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230209094417.21630-1-jfalempe@redhat.com
-rw-r--r--drivers/gpu/drm/ast/ast_mode.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index c7443317c747ca..66a4a41c3fe944 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 = 0; /* with shmem, the primary plane is always at offset 0 */
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;
@@ -972,7 +972,7 @@ static int ast_cursor_plane_init(struct ast_private *ast)
return -ENOMEM;
vaddr = ast->vram + ast->vram_fb_available - size;
- offset = ast->vram_base + ast->vram_fb_available - size;
+ offset = ast->vram_fb_available - size;
ret = ast_plane_init(dev, ast_cursor_plane, vaddr, offset, size,
0x01, &ast_cursor_plane_funcs,