linux-stable.git/drivers/gpu/drm/tilcdc, branch linux-5.10.y

tilcdc: tilcdc_external: fix an incorrect NULL check on list iterator

2022-06-09T08:21:28+00:00

commit 8b917cbe38e9b0d002492477a9fc2bfee2412ce4 upstream.

The bug is here:
	if (!encoder) {

The list iterator value 'encoder' will *always* be set and non-NULL
by list_for_each_entry(), so it is incorrect to assume that the
iterator value will be NULL if the list is empty or no element
is found.

To fix the bug, use a new variable 'iter' as the list iterator,
while use the original variable 'encoder' as a dedicated pointer
to point to the found element.

Cc: stable@vger.kernel.org
Fixes: ec9eab097a500 ("drm/tilcdc: Add drm bridge support for attaching drm bridge drivers")
Signed-off-by: Xiaomeng Tong 
Reviewed-by: Jyri Sarha 
Tested-by: Jyri Sarha 
Signed-off-by: Jyri Sarha 
Link: https://patchwork.freedesktop.org/patch/msgid/20220327061516.5076-1-xiam0nd.tong@gmail.com
Signed-off-by: Greg Kroah-Hartman

drm/tilcdc: send vblank event when disabling crtc

2021-05-14T07:50:21+00:00

[ Upstream commit f1a75f4dd8edf272b6b7cdccf6ba6254ec9d15fa ]

When run xrandr to change resolution on Beaglebone Black board, it will
print the error information:

root@beaglebone:~# xrandr -display :0 --output HDMI-1 --mode 720x400
[drm:drm_crtc_commit_wait] *ERROR* flip_done timed out
[drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [CRTC:32:tilcdc crtc] commit wait timed out
[drm:drm_crtc_commit_wait] *ERROR* flip_done timed out
[drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [CONNECTOR:34:HDMI-A-1] commit wait timed out
[drm:drm_crtc_commit_wait] *ERROR* flip_done timed out
[drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [PLANE:31:plane-0] commit wait timed out
tilcdc 4830e000.lcdc: already pending page flip!

This is because there is operation sequence as below:

drm_atomic_connector_commit_dpms(mode is DRM_MODE_DPMS_OFF):
    ...
    drm_atomic_helper_setup_commit <- init_completion(commit_A->flip_done)
    drm_atomic_helper_commit_tail
        tilcdc_crtc_atomic_disable
        tilcdc_plane_atomic_update <- drm_crtc_send_vblank_event in tilcdc_crtc_irq
                                      is skipped since tilcdc_crtc->enabled is 0
        tilcdc_crtc_atomic_flush   <- drm_crtc_send_vblank_event is skipped since
                                      crtc->state->event is set to be NULL in
                                      tilcdc_plane_atomic_update
drm_mode_setcrtc:
    ...
    drm_atomic_helper_setup_commit <- init_completion(commit_B->flip_done)
    drm_atomic_helper_wait_for_dependencies
        drm_crtc_commit_wait   <- wait for commit_A->flip_done completing

Just as shown above, the steps which could complete commit_A->flip_done
are all skipped and commit_A->flip_done will never be completed. This will
result a time-out ERROR when drm_crtc_commit_wait check the commit_A->flip_done.
So add drm_crtc_send_vblank_event in tilcdc_crtc_atomic_disable to
complete commit_A->flip_done.

Fixes: cb345decb4d2 ("drm/tilcdc: Use standard drm_atomic_helper_commit")
Signed-off-by: Quanyang Wang 
Reviewed-by: Jyri Sarha 
Tested-by: Jyri Sarha 
Signed-off-by: Jyri Sarha 
Link: https://patchwork.freedesktop.org/patch/msgid/20210209082415.382602-1-quanyang.wang@windriver.com
Signed-off-by: Sasha Levin

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva

drm/tilcdc: Use standard drm_atomic_helper_commit

2020-07-14T08:32:33+00:00

Gives us proper nonblocking support for free, and a pile of other
things. The tilcdc code is simply old enough that it was never
converted over, but was stuck forever with the copypasta from when it
was initially merged.

The riskiest thing with this conversion is maybe that there's an issue
with the vblank handling or vblank event handling, which will upset
the modern commit support in atomic helpers. But from a cursory review
drm_crtc_vblank_on/off is called in the right places, and the event
handling also seems to exist (albeit with much hand-rolling and
probably some races, could perhaps be converted over to
drm_crtc_arm_vblank_event without any real loss).

Motivated by me not having to hand-roll the dma-fence annotations for
this.

v2: Clear out crtc_state->event when we're handling the event, to
avoid upsetting the helpers (reported by Jyri).

v3: Also send out even whent the crtc is getting disabled. Tilcdc looks a
bit like conversion to simple display helpers would work out really
nice.

Tested-by: Jyri Sarha 
Reviewed-by: Jyri Sarha 
Signed-off-by: Daniel Vetter 
Cc: Jyri Sarha 
Cc: Tomi Valkeinen 
Link: https://patchwork.freedesktop.org/patch/msgid/20200708142050.530240-1-daniel.vetter@ffwll.ch

drm/tilcdc: Set GEM CMA functions with DRM_GEM_CMA_DRIVER_OPS

2020-06-10T07:05:58+00:00

DRM_GEM_CMA_DRIVER_OPS sets the functions in struct drm_driver
to their defaults. No functional changes are made.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Emil Velikov 
Link: https://patchwork.freedesktop.org/patch/msgid/20200605073247.4057-39-tzimmermann@suse.de

drm/tilcdc: Use GEM CMA object functions

2020-06-10T07:05:51+00:00

Create GEM objects with drm_gem_cma_create_object_default_funcs(), which
allocates the object and sets CMA's default object functions. Corresponding
callbacks in struct drm_driver are cleared. No functional changes are made.

Driver and object-function instances use the same callback functions, with
the exception of vunmap. The implementation of vunmap is empty and left out
in CMA's default object functions.

v3:
	* convert to DRIVER_OPS macro in a separate patch

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Emil Velikov 
Link: https://patchwork.freedesktop.org/patch/msgid/20200605073247.4057-38-tzimmermann@suse.de

drm/tilcdc: add missing static for panel_driver

2020-05-19T06:56:58+00:00

struct platform_driver panel_driver is only used from tilcdc_panel.c, so
it can be static.

Signed-off-by: Tomi Valkeinen 
Link: https://patchwork.freedesktop.org/patch/msgid/20200429104234.18910-3-tomi.valkeinen@ti.com
Reviewed-by: Jyri Sarha 
Acked-by: Sam Ravnborg

drm/tilcdc: remove unnecessary state->fb check

2020-05-19T06:56:58+00:00

tilcdc_plane_atomic_check() exits if state->fb == NULL, so no need to
check it again later.

Signed-off-by: Tomi Valkeinen 
Link: https://patchwork.freedesktop.org/patch/msgid/20200429104234.18910-2-tomi.valkeinen@ti.com
Reviewed-by: Jyri Sarha

drm/tilcdc: fix leak & null ref in panel_connector_get_modes

2020-05-19T06:56:40+00:00

If videomode_from_timings() returns true, the mode allocated with
drm_mode_create will be leaked.

Also, the return value of drm_mode_create() is never checked, and thus
could cause NULL deref.

Fix these two issues.

Signed-off-by: Tomi Valkeinen 
Link: https://patchwork.freedesktop.org/patch/msgid/20200429104234.18910-1-tomi.valkeinen@ti.com
Reviewed-by: Jyri Sarha 
Acked-by: Sam Ravnborg

drm/tilcdc: use devm_of_find_backlight

2020-05-17T12:55:29+00:00

Look up backlight device using devm_of_find_backlight().
This simplifies the code and prevents us from hardcoding
the node name in the driver.

Signed-off-by: Sam Ravnborg 
Reviewed-by: Tomi Valkeinen 
Cc: Jyri Sarha 
Cc: Tomi Valkeinen 
Link: https://patchwork.freedesktop.org/patch/msgid/20200514191001.457441-3-sam@ravnborg.org