diff options
| author | Thomas Zimmermann <tzimmermann@suse.de> | 2025-03-28 10:17:05 +0100 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2025-04-01 15:35:11 +0200 |
| commit | 4bfb389a0136a13f0802eeb5e97a0e76d88f77ae (patch) | |
| tree | 0c23d46ce2dd11e2f8e7a52f9e79b2ef2380e05a | |
| parent | bfb20a655848a9088e3e9ae24b1dcce1bbf016c2 (diff) | |
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
| -rw-r--r-- | drivers/gpu/drm/tiny/cirrus-qemu.c | 1 |
1 files changed, 0 insertions, 1 deletions
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); |