diff options
| author | Thomas Zimmermann <tzimmermann@suse.de> | 2025-10-14 10:46:34 +0200 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2025-10-15 09:55:35 +0200 |
| commit | 6f719373b943a955fee6fc2012aed207b65e2854 (patch) | |
| tree | cbbf70f68ad29f3380cef96618d531cfbfed128d /drivers/gpu/drm/ast/ast_mode.c | |
| parent | 52e59f7740ba23bbb664914967df9a00208ca10c (diff) | |
drm/ast: Blank with VGACR17 sync enable, always clear VGACRB6 sync off
Blank the display by disabling sync pulses with VGACR17<7>. Unblank
by reenabling them. This VGA setting should be supported by all Aspeed
hardware.
Ast currently blanks via sync-off bits in VGACRB6. Not all BMCs handle
VGACRB6 correctly. After disabling sync during a reboot, some BMCs do
not reenable it after the soft reset. The display output remains dark.
When the display is off during boot, some BMCs set the sync-off bits in
VGACRB6, so the display remains dark. Observed with Blackbird AST2500
BMCs. Clearing the sync-off bits unconditionally fixes these issues.
Also do not modify VGASR1's SD bit for blanking, as it only disables GPU
access to video memory.
v2:
- init vgacrb6 correctly (Jocelyn)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: ce3d99c83495 ("drm: Call drm_atomic_helper_shutdown() at shutdown time for misc drivers")
Tested-by: Nick Bowler <nbowler@draconx.ca>
Reported-by: Nick Bowler <nbowler@draconx.ca>
Closes: https://lore.kernel.org/dri-devel/wpwd7rit6t4mnu6kdqbtsnk5bhftgslio6e2jgkz6kgw6cuvvr@xbfswsczfqsi/
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.7+
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20251014084743.18242-1-tzimmermann@suse.de
Diffstat (limited to 'drivers/gpu/drm/ast/ast_mode.c')
| -rw-r--r-- | drivers/gpu/drm/ast/ast_mode.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index b4e8edc7c767..30b011ed0a05 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -836,22 +836,24 @@ ast_crtc_helper_atomic_flush(struct drm_crtc *crtc, static void ast_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_state *state) { struct ast_device *ast = to_ast_device(crtc->dev); + u8 vgacr17 = 0x00; + u8 vgacrb6 = 0xff; - ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0xfc, 0x00); - ast_set_index_reg_mask(ast, AST_IO_VGASRI, 0x01, 0xdf, 0x00); + vgacr17 |= AST_IO_VGACR17_SYNC_ENABLE; + vgacrb6 &= ~(AST_IO_VGACRB6_VSYNC_OFF | AST_IO_VGACRB6_HSYNC_OFF); + + ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x17, 0x7f, vgacr17); + ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0xfc, vgacrb6); } static void ast_crtc_helper_atomic_disable(struct drm_crtc *crtc, struct drm_atomic_state *state) { struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(state, crtc); struct ast_device *ast = to_ast_device(crtc->dev); - u8 vgacrb6; + u8 vgacr17 = 0xff; - ast_set_index_reg_mask(ast, AST_IO_VGASRI, 0x01, 0xdf, AST_IO_VGASR1_SD); - - vgacrb6 = AST_IO_VGACRB6_VSYNC_OFF | - AST_IO_VGACRB6_HSYNC_OFF; - ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0xfc, vgacrb6); + vgacr17 &= ~AST_IO_VGACR17_SYNC_ENABLE; + ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0x17, 0x7f, vgacr17); /* * HW cursors require the underlying primary plane and CRTC to |