On 27/01/2025 12:55, Thomas Zimmermann wrote:
Hi
Am 24.01.25 um 15:11 schrieb Jocelyn Falempe:
ast_dp_is_connected() used to also check for link training success
to report the DP connector as connected. Without this check, the
physical_status is always connected. So if no monitor is present, it
will fail to read the EDID and set the default resolution to 640x480
instead of 1024x768.
Signed-off-by: Jocelyn Falempe <jfalempe@xxxxxxxxxx>
Fixes: 2281475168d2 ("drm/ast: astdp: Perform link training during
atomic_enable")
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # v6.12+
I cannot reproduce the problem, but the patch looks correct. My AST2600
with ASTDP still works correctly with the patch allied.
Thanks, interesting that it doesn't affect all hardwares.
I got reports from two different vendors about this issue.
If no other comments, I will push it to drm-misc-next tomorrow (only
adding reported-by: and tested-by: tags).
--
Jocelyn
Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Best regards
Thomas
---
drivers/gpu/drm/ast/ast_dp.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/ast/ast_dp.c b/drivers/gpu/drm/ast/ast_dp.c
index 0e282b7b167c..30aad5c0112a 100644
--- a/drivers/gpu/drm/ast/ast_dp.c
+++ b/drivers/gpu/drm/ast/ast_dp.c
@@ -17,6 +17,12 @@ static bool ast_astdp_is_connected(struct
ast_device *ast)
{
if (!ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDF,
AST_IO_VGACRDF_HPD))
return false;
+ /*
+ * HPD might be set even if no monitor is connected, so also
check that
+ * the link training was successful.
+ */
+ if (!ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDC,
AST_IO_VGACRDC_LINK_SUCCESS))
+ return false;
return true;
}
base-commit: 798047e63ac970f105c49c22e6d44df901c486b2
