linux/drivers/gpu
Matthias Kaehlcke bee447e224 drm/bridge: dw-hdmi: Refuse DDC/CI transfers on the internal I2C controller
The DDC/CI protocol involves sending a multi-byte request to the
display via I2C, which is typically followed by a multi-byte
response. The internal I2C controller only allows single byte
reads/writes or reads of 8 sequential bytes, hence DDC/CI is not
supported when the internal I2C controller is used. The I2C
transfers complete without errors, however the data in the response
is garbage. Abort transfers to/from slave address 0x37 (DDC) with
-EOPNOTSUPP, to make it evident that the communication is failing.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Sean Paul <sean@poorly.run>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191002124354.v2.1.I709dfec496f5f0b44a7b61dcd4937924da8d8382@changeid
2019-10-07 14:27:48 +02:00
..
drm drm/bridge: dw-hdmi: Refuse DDC/CI transfers on the internal I2C controller 2019-10-07 14:27:48 +02:00
host1x drm/tegra: Changes for v5.3-rc1 2019-06-25 12:59:43 +10:00
ipu-v3 gpu: ipu-v3: image-convert: only sample into the next tile if necessary 2019-08-19 16:25:30 +02:00
vga topic/remove-fbcon-notifiers: 2019-06-26 12:26:34 +02:00
Makefile