On Thu, May 07, 2020 at 11:06:40AM +0200, Thomas Zimmermann wrote:

Suspending failed because there's no mode if the CRTC is being disabled. Early-out in this case. This fixes runtime PM for ast.

v3:

• fixed commit message

v2:

• added Tested-by/Reported-by tags
• added Fixes tags and CC (Sam)
• improved comment

Signed-off-by: Thomas Zimmermann tzimmermann@suse.de Reported-by: Cary Garrett cogarre@gmail.com Tested-by: Cary Garrett cogarre@gmail.com Fixes: b48e1b6ffd28 ("drm/ast: Add CRTC helpers for atomic modesetting") Cc: Thomas Zimmermann tzimmermann@suse.de Cc: Gerd Hoffmann kraxel@redhat.com Cc: Dave Airlie airlied@redhat.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Sam Ravnborg sam@ravnborg.org Cc: stable@vger.kernel.org # v5.6+

---

drivers/gpu/drm/ast/ast_mode.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 7a9f20a2fd303..0cbbb21edb4e1 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -801,6 +801,9 @@ static int ast_crtc_helper_atomic_check(struct drm_crtc *crtc, return -EINVAL; }

• if (!state->enable)

• return 0; /* no mode checks if CRTC is being disabled */
  

• ast_state = to_ast_crtc_state(state);

  format = ast_state->format;

hey, I'm seeing a regression that I bisected down to this change. I installed GNOME on a couple of different server models that have AMI-based BMCs, which provide a web-based graphics display (virtual KVM). When I enter the lock screen on current upstream kernels, the display freezes, and I see the following messages appear in syslog whenever I generate keyboard/mouse events on that display:

Jan 19 20:34:53 starbuck gnome-shell[5002]: Failed to post KMS update: drmModeAtomicCommit: Invalid argument Jan 19 20:34:53 starbuck gnome-shell[5002]: Page flip discarded: drmModeAtomicCommit: Invalid argument Jan 19 20:34:53 starbuck gnome-shell[5002]: Failed to post KMS update: drmModeAtomicCommit: Invalid argument Jan 19 20:34:53 starbuck gnome-shell[5002]: Page flip discarded: drmModeAtomicCommit: Invalid argument Jan 19 20:34:53 starbuck gnome-shell[5002]: Failed to post KMS update: drmModeAtomicCommit: Invalid argument Jan 19 20:34:53 starbuck gnome-shell[5002]: Page flip discarded: drmModeAtomicCommit: Invalid argument Jan 19 20:34:53 starbuck gnome-shell[5002]: Failed to post KMS update: drmModeAtomicCommit: Invalid argument

If I back out this change w/ the following patch (code has evolved slightly preventing a clean revert), then the lock screen once again behaves normally:

diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c index 956c8982192b..336c545c46f5 100644 --- a/drivers/gpu/drm/ast/ast_mode.c +++ b/drivers/gpu/drm/ast/ast_mode.c @@ -1012,9 +1012,6 @@ static int ast_crtc_helper_atomic_check(struct drm_crtc *crtc, const struct drm_format_info *format; bool succ;

- if (!crtc_state->enable) - return 0; /* no mode checks if CRTC is being disabled */ - ast_state = to_ast_crtc_state(crtc_state);

format = ast_state->format;

Apologies for noticing so long after the fact. I don't normally run a desktop environment on these servers, I just happened to be debugging something recently that required it.

-dann