Patch "drm/ast: Fix ast_dp connection status" has been added to the 6.12-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    drm/ast: Fix ast_dp connection status

to the 6.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-ast-fix-ast_dp-connection-status.patch
and it can be found in the queue-6.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.


>From c28f72c6ca98e039c2aa5aac6752c416bc31dbab Mon Sep 17 00:00:00 2001
From: Jocelyn Falempe <jfalempe at redhat.com>
Date: Fri, 24 Jan 2025 15:11:31 +0100
Subject: drm/ast: Fix ast_dp connection status

From: Jocelyn Falempe <jfalempe at redhat.com>

commit c28f72c6ca98e039c2aa5aac6752c416bc31dbab upstream.

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 at redhat.com>
Fixes: 2281475168d2 ("drm/ast: astdp: Perform link training during atomic_enable")
Reported-by: Jerry Hoemann <jerry.hoemann at hpe.com>
Tested-by: Jose Lopez <jose.lopez at hpe.com>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: Dave Airlie <airlied at redhat.com>
Cc: dri-devel at lists.freedesktop.org
Cc: <stable at vger.kernel.org> # v6.12+
Reviewed-by: Thomas Zimmermann <tzimmermann at suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20250124141142.2434138-1-jfalempe@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 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;
 }
 
-- 
2.49.0



Patches currently in stable-queue which might be from jfalempe at redhat.com are

queue-6.12/drm-ast-fix-ast_dp-connection-status.patch