FAILED: patch "[PATCH] drm/cirrus-qemu: Fix pitch programming" failed to apply to 5.10-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 4bfb389a0136a13f0802eeb5e97a0e76d88f77ae
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025063024-nibble-exit-e642@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 4bfb389a0136a13f0802eeb5e97a0e76d88f77ae Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: Fri, 28 Mar 2025 10:17:05 +0100
Subject: [PATCH] drm/cirrus-qemu: Fix pitch programming

Do not set CR1B[6] when programming the pitch. The bit effects VGA
text mode and is not interpreted by qemu. [1] It has no affect on
the scanline pitch.

The scanline bit that is set into CR1B[6] belongs into CR13[7], which
the driver sets up correctly.

This bug goes back to the driver's initial commit.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://gitlab.com/qemu-project/qemu/-/blob/stable-9.2/hw/display/cirrus_vga.c?ref_type=heads#L1112 # 1
Fixes: f9aa76a85248 ("drm/kms: driver for virtual cirrus under qemu")
Cc: Adam Jackson <ajax@redhat.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: <stable@vger.kernel.org> # v3.5+
Link: https://lore.kernel.org/r/20250328091821.195061-2-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/tiny/cirrus-qemu.c b/drivers/gpu/drm/tiny/cirrus-qemu.c
index 52ec1e4ea9e5..a00d3b7ded6c 100644
--- a/drivers/gpu/drm/tiny/cirrus-qemu.c
+++ b/drivers/gpu/drm/tiny/cirrus-qemu.c
@@ -318,7 +318,6 @@ static void cirrus_pitch_set(struct cirrus_device *cirrus, unsigned int pitch)
 	/* Enable extended blanking and pitch bits, and enable full memory */
 	cr1b = 0x22;
 	cr1b |= (pitch >> 7) & 0x10;
-	cr1b |= (pitch >> 6) & 0x40;
 	wreg_crt(cirrus, 0x1b, cr1b);
 
 	cirrus_set_start_address(cirrus, 0);