Replace the use of the fbdev software device, stored in struct
fb_info.dev, with the hardware device from struct fb_info.device
in load_waveform(). The device is only used for printing errors
with dev_err().
This change aligns load_waveform() with the rest of the driver and
prepares fbdev for making struct fb_info.dev optional.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-18-tzimmermann@suse.de
Call drm_gem_prime_handle_to_fd() and drm_gem_prime_fd_to_handle() by
default if no PRIME import/export helpers have been set. Both functions
are the default for almost all drivers.
DRM drivers implement struct drm_driver.gem_prime_import_sg_table
to import dma-buf objects from other drivers. Having the function
drm_gem_prime_fd_to_handle() functions set by default allows each
driver to import dma-buf objects to itself, even without support for
other drivers.
For drm_gem_prime_handle_to_fd() it is similar: using it by default
allows each driver to export to itself, even without support for other
drivers.
This functionality enables userspace to share per-driver buffers
across process boundaries via PRIME (e.g., wlroots requires this
functionality). The patch generalizes a pattern that has previously
been implemented by GEM VRAM helpers [1] to work with any driver.
For example, gma500 can now run the wlroots-based sway compositor.
v2:
* clean up docs and TODO comments (Simon, Zack)
* clean up style in drm_getcap()
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/dri-devel/20230302143502.500661-1-contact@emersion.fr/ # 1
Reviewed-by: Simon Ser <contact@emersion.fr>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230620080252.16368-2-tzimmermann@suse.de
The spinlock composer_lock protects the variables crc_pending,
wb_pending, frame_start and frame_end, which are variables that are used
by the composer worker. There is no need to protect the wb_frame_info
information with a spinlock. Therefore, reduce the critical section of
the lock by removing the assignments to the wb_frame_info from the
critical section.
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Arthur Grillo <arthurgrillo@riseup.net>
Signed-off-by: Maíra Canal <mairacanal@riseup.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20230515135204.115393-2-mcanal@igalia.com
In order to read the EDID from an eDP panel, you not only need to
power on the bridge chip itself but also the panel. In the ps8640
driver, this was made to work by having the bridge chip manually power
the panel on by calling pre_enable() on everything connectorward on
the bridge chain. This worked OK, but...
...when trying to do the same thing on ti-sn65dsi86, feedback was that
this wasn't a great idea. As a result, we designed the "DP AUX"
bus. With the design we ended up with the panel driver itself was in
charge of reading the EDID. The panel driver could power itself on and
the bridge chip was able to power itself on because it implemented the
DP AUX bus.
Despite the fact that we came up with a new scheme, implemented in on
ti-sn65dsi86, and even implemented it on parade-ps8640, we still kept
the old code around. This was because the new scheme required a DT
change. Previously the panel was a simple "platform_device" and in DT
at the top level. With the new design the panel needs to be listed in
DT under the DP controller node. The old code allowed us to properly
fetch EDIDs with ps8640 with the old DTs.
Unfortunately, the old code stopped working as of commit 102e80d1fa
("drm/bridge: ps8640: Use atomic variants of drm_bridge_funcs"). There
are cases at bootup where connector->state->state is NULL and the
kernel crashed at:
* drm_atomic_bridge_chain_pre_enable
* drm_atomic_get_old_bridge_state
* drm_atomic_get_old_private_obj_state
The crash went away at commit 4fb912e5e1 ("drm/bridge: Introduce
pre_enable_prev_first to alter bridge init order") which added a NULL
check. However, even though we were no longer crashing the end result
was that we weren't actually powering the panel on when we thought we
were. Things could end up working (despite warning splats) if
userspace was persistent and tried to get the mode again, but it
wasn't great.
A bit of digging was done to see if there was an easy fix but there
was nothing obvious. Instead, the only device using ps8640 the "old"
way had its DT updated so that the panel was no longer a simple
"platform_deice". See commit c2d94f7214 ("arm64: dts: mediatek:
mt8173-elm: Move display to ps8640 auxiliary bus") and commit
113b5cc06f44 ("arm64: dts: mediatek: mt8173-elm: remove panel model
number in DT").
Let's delete the old broken code so nobody gets tempted to copy it or
figure out how it works (since it doesn't).
NOTE: from a device tree "purist" point of view, we're supposed to
keep old device trees working and this patch is technically "against
policy". Reasons I'm still proposing it anyway:
1. Officially, old mt8173-elm device trees worked via the "little
white lie" approach. The DT would list an arbitrary/representative
panel that would be used for power sequencing. The mode information
in the panel driver would then be ignored / overridden by the EDID
reading code in ps8640. I don't feel too terrible breaking DTs that
contained the wrong "compatible" string to begin with. NOTE that
any old device trees that _didn't_ lie about their compatible will
still work because the mode information will come from the
hardcoded panels in panel-edp.
2. The only users of the old code were Chromebooks and Chromebooks
don't bake their DTs into the BIOS (they are bundled with the
kernel). Thus we don't need to worry about breaking someone using
an old DT with a new kernel.
3. The old code was broken anyway. If someone wants to fix the old
code instead of deleting it then they have my blessing, but without
a proper fix the old code isn't useful.
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230616165517.v2.1.I7b8f60b3fbfda068f9bf452d584dc934494bfbfa@changeid
Before this patch, booting to Linux VT and doing a simple:
echo 2 > /sys/class/graphics/fb0/blank
echo 0 > /sys/class/graphics/fb0/blank
would result in failures to re-enable the panel. Mode set callback is
called only once during boot in this scenario, while calls to
enable/disable callbacks are balanced afterwards. The driver doesn't
work unless userspace calls modeset before enabling the CRTC/connector.
This patch moves enabling of the DSI host from mode_set into pre_enable
callback, and removes some old hacks where this bridge driver is
directly calling into other bridge driver's callbacks.
pre_enable_prev_first flag is set on the panel's bridge so that panel
drivers will get their prepare function called between DSI host's
pre_enable and enable callbacks, so that they get a chance to
perform panel setup while DSI host is already enabled in command
mode. Otherwise panel's prepare would be called before DSI host
is enabled, and any DSI communication used in prepare callback
would fail.
With all these changes, the enable/disable sequence is now well
balanced, and host's and panel's callbacks are called in proper order
documented in the drm_panel API documentation without needing the old
hacks. (Mainly that panel->prepare is called when DSI host is ready to
allow the panel driver to send DSI commands and vice versa during
disable.)
Tested on Pinephone Pro. Trace of the callbacks follows.
Before:
[ 1.253882] dw-mipi-dsi-rockchip ff960000.dsi: mode_set
[ 1.290732] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 1.475576] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 1.475593] panel-himax-hx8394 ff960000.dsi.0: enable
echo 2 > /sys/class/graphics/fb0/blank
[ 13.722799] panel-himax-hx8394 ff960000.dsi.0: disable
[ 13.774502] dw-mipi-dsi-rockchip ff960000.dsi: post_disable
[ 13.774526] panel-himax-hx8394 ff960000.dsi.0: unprepare
echo 0 > /sys/class/graphics/fb0/blank
[ 17.735796] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 17.923522] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 17.923540] panel-himax-hx8394 ff960000.dsi.0: enable
[ 17.944330] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command FIFO
[ 17.944335] panel-himax-hx8394 ff960000.dsi.0: sending command 0xb9 failed: -110
[ 17.944340] panel-himax-hx8394 ff960000.dsi.0: Panel init sequence failed: -110
echo 2 > /sys/class/graphics/fb0/blank
[ 431.148583] panel-himax-hx8394 ff960000.dsi.0: disable
[ 431.169259] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command FIFO
[ 431.169268] panel-himax-hx8394 ff960000.dsi.0: Failed to enter sleep mode: -110
[ 431.169282] dw-mipi-dsi-rockchip ff960000.dsi: post_disable
[ 431.169316] panel-himax-hx8394 ff960000.dsi.0: unprepare
[ 431.169357] pclk_mipi_dsi0 already disabled
echo 0 > /sys/class/graphics/fb0/blank
[ 432.796851] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 432.981537] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 432.981568] panel-himax-hx8394 ff960000.dsi.0: enable
[ 433.002290] dw-mipi-dsi-rockchip ff960000.dsi: failed to write command FIFO
[ 433.002299] panel-himax-hx8394 ff960000.dsi.0: sending command 0xb9 failed: -110
[ 433.002312] panel-himax-hx8394 ff960000.dsi.0: Panel init sequence failed: -110
-----------------------------------------------------------------------
After:
[ 1.248372] dw-mipi-dsi-rockchip ff960000.dsi: mode_set
[ 1.248704] dw-mipi-dsi-rockchip ff960000.dsi: pre_enable
[ 1.285377] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 1.468392] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 1.468421] panel-himax-hx8394 ff960000.dsi.0: enable
echo 2 > /sys/class/graphics/fb0/blank
[ 16.210357] panel-himax-hx8394 ff960000.dsi.0: disable
[ 16.261315] dw-mipi-dsi-rockchip ff960000.dsi: post_disable
[ 16.261339] panel-himax-hx8394 ff960000.dsi.0: unprepare
echo 0 > /sys/class/graphics/fb0/blank
[ 19.161453] dw-mipi-dsi-rockchip ff960000.dsi: pre_enable
[ 19.197869] panel-himax-hx8394 ff960000.dsi.0: prepare
[ 19.382141] dw-mipi-dsi-rockchip ff960000.dsi: enable
[ 19.382158] panel-himax-hx8394 ff960000.dsi.0: enable
(But depends on functionality intorduced in Linux 6.3, so this patch will
not build on older kernels when applied to older stable branches.)
Fixes: 46fc51546d ("drm/bridge/synopsys: Add MIPI DSI host controller bridge")
Signed-off-by: Ondrej Jirman <megi@xff.cz>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230617224915.1923630-1-megi@xff.cz
