diff options
| author | Thomas Zimmermann <tzimmermann@suse.de> | 2026-03-27 14:32:53 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-04-11 14:29:44 +0200 |
| commit | 2a98748211fb3941087e05f6d1e0f17d05d9822e (patch) | |
| tree | 7acdc99a6fd98b4bb19eb8a5c17ff997a9f8d154 /drivers/gpu | |
| parent | 3124600a7558a5596664960063e29bebc09dc958 (diff) | |
drm/ast: dp501: Fix initialization of SCU2C
commit 2f42c1a6161646cbd29b443459fd635d29eda634 upstream.
Ast's DP501 initialization reads the register SCU2C at offset 0x1202c
and tries to set it to source data from VGA. But writes the update to
offset 0x0, with unknown results. Write the result to SCU instead.
The bug only happens in ast_init_analog(). There's similar code in
ast_init_dvo(), which works correctly.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 83c6620bae3f ("drm/ast: initial DP501 support (v0.2)")
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v3.16+
Link: https://patch.msgid.link/20260327133532.79696-2-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/ast/ast_dp501.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/ast/ast_dp501.c b/drivers/gpu/drm/ast/ast_dp501.c index 9e19d8c17730..677c52c0d99a 100644 --- a/drivers/gpu/drm/ast/ast_dp501.c +++ b/drivers/gpu/drm/ast/ast_dp501.c @@ -436,7 +436,7 @@ static void ast_init_analog(struct ast_device *ast) /* Finally, clear bits [17:16] of SCU2c */ data = ast_read32(ast, 0x1202c); data &= 0xfffcffff; - ast_write32(ast, 0, data); + ast_write32(ast, 0x1202c, data); /* Disable DVO */ ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xa3, 0xcf, 0x00); |