[PATCH 0/5] drm/dp: i2c-over-aux short write support

ville.syrjala at linux.intel.com ville.syrjala at linux.intel.com
Fri Mar 13 09:13:16 PDT 2015


From: Ville Syrjälä <ville.syrjala at linux.intel.com>

This series tries to implement support for short i2c-over-aux writes.

I did notice that my monitor (HP ZR24w) does support DDC/CI so I was
able to do some writes, but I only saw native defers instead of i2c
defers/short acks. So I've not actually been able to test this.

Another complication with DDC/CI seems to be that the monitor doesn't
seem to like the default 100kHz bus speed. I had to drop it to 10kHz
to make it reliable (my dongle supports bus speed control fortunately).
Currently we have no standard way to configure the bus speed AFAICS,
so at least with this monitor DDC/CI is a bit useless.

I tried to fix up radeon and tegra too. gma500 I left alone since it's
not using dp i2c helper.

Ville Syrjälä (5):
  drm/dp: s/I2C_STATUS/I2C_WRITE_STATUS_UPDATE/
  drm/i915: Handle DP_AUX_I2C_WRITE_STATUS_UPDATE
  drm/radeon: Handle DP_AUX_I2C_WRITE_STATUS_UPDATE
  drm/tegra: Handle I2C_WRITE_STATUS_UPDATE for address only writes
  drm/dp: Use I2C_WRITE_STATUS_UPDATE to drain partial I2C_WRITE
    requests

 drivers/gpu/drm/drm_dp_helper.c      | 42 ++++++++++++++++++++++++++++++++----
 drivers/gpu/drm/i915/intel_dp.c      |  1 +
 drivers/gpu/drm/radeon/atombios_dp.c |  1 +
 drivers/gpu/drm/tegra/dpaux.c        |  3 ++-
 include/drm/drm_dp_helper.h          |  2 +-
 5 files changed, 43 insertions(+), 6 deletions(-)

-- 
2.0.5



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