drm/i915: Actually retry with bit-banging after GMBUS timeout
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Mon, 7 Mar 2016 15:56:57 +0000 (17:56 +0200)
committerJani Nikula <jani.nikula@intel.com>
Fri, 11 Mar 2016 08:23:28 +0000 (10:23 +0200)
commit0bbca274a31c2366414d8d3f95e03d1c4674d93f
treeafe4fe667610d628afd23905c5ecfb236f7ee846
parent2f791908a70e95768596f5bb9e6de4f441d7bf13
drm/i915: Actually retry with bit-banging after GMBUS timeout

After the GMBUS transfer times out, we set force_bit=1 and
return -EAGAIN expecting the i2c core to call the .master_xfer
hook again so that we will retry the same transfer via bit-banging.
This is in case the gmbus hardware is somehow faulty.

Unfortunately we left adapter->retries to 0, meaning the i2c core
didn't actually do the retry. Let's tell the core we want one retry
when we return -EAGAIN.

Note that i2c-algo-bit also uses this retry count for some internal
retries, so we'll end up increasing those a bit as well.

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: drm-intel-fixes@lists.freedesktop.org
Fixes: bffce907d640 ("drm/i915: abstract i2c bit banging fallback in gmbus xfer")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1457366220-29409-2-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
(cherry picked from commit 8b1f165a4a8f64c28cf42d10e1f4d3b451dedc51)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
drivers/gpu/drm/i915/intel_i2c.c