drm/dp/mst: Configure no_stop_bit correctly for remote i2c xfers
[ Upstream commit c978ae9bde582e82a04c63a4071701691dd8b35c ]
We aren't supposed to force a stop+start between every i2c msg
when performing multi message transfers. This should eg. cause
the DDC segment address to be reset back to 0 between writing
the segment address and reading the actual EDID extension block.
To quote the E-DDC spec:
"... this standard requires that the segment pointer be
reset to 00h when a NO ACK or a STOP condition is received."
Since we're going to touch this might as well consult the
I2C_M_STOP flag to determine whether we want to force the stop
or not.
Cc: Brian Vincent <brainn@gmail.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=108081
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180928180403.22499-1-ville.syrjala@linux.intel.com
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
1 file changed