From: Nirmoy Das <nirmoyd@nvidia.com>
Date: Mon, 29 Sep 2025 15:50:10 +0000 (-0400)
Subject: drm/ast: Use msleep instead of mdelay for edid read
X-Git-Tag: v6.6.109~16
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7ea47a560a7a3e7edc6d33dea9e141737a75d742;p=thirdparty%2Fkernel%2Fstable.git

drm/ast: Use msleep instead of mdelay for edid read

[ Upstream commit c7c31f8dc54aa3c9b2c994b5f1ff7e740a654e97 ]

The busy-waiting in `mdelay()` can cause CPU stalls and kernel timeouts
during boot.

Signed-off-by: Nirmoy Das <nirmoyd@nvidia.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Carol L Soto csoto@nvidia.com<mailto:csoto@nvidia.com>
Fixes: 594e9c04b586 ("drm/ast: Create the driver for ASPEED proprietory Display-Port")
Cc: KuoHsiang Chou <kuohsiang_chou@aspeedtech.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.19+
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250917194346.2905522-1-nirmoyd@nvidia.com
[ Applied change to ast_astdp_read_edid() instead of ast_astdp_read_edid_block() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/gpu/drm/ast/ast_dp.c b/drivers/gpu/drm/ast/ast_dp.c
index c6f226b6f0813..fc9c36c8b81b9 100644
--- a/drivers/gpu/drm/ast/ast_dp.c
+++ b/drivers/gpu/drm/ast/ast_dp.c
@@ -62,7 +62,7 @@ int ast_astdp_read_edid(struct drm_device *dev, u8 *ediddata)
 			 *	  of right-click of mouse.
 			 * 2. The Delays are often longer a lot when system resume from S3/S4.
 			 */
-			mdelay(j+1);
+			msleep(j + 1);
 
 			if (!(ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xD1,
 							ASTDP_MCU_FW_EXECUTING) &&