The patch below does not apply to the 5.15-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-5.15.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 '2025063023-underfoot-alright-f57c@gregkh' --subject-prefix 'PATCH 5.15.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... # 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);