From: Ville Syrjälä Date: Mon, 7 Mar 2016 15:56:57 +0000 (+0200) Subject: drm/i915: Actually retry with bit-banging after GMBUS timeout X-Git-Tag: v4.14-rc1~2738^2~45^2~536 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8b1f165a4a8f64c28cf42d10e1f4d3b451dedc51;p=platform%2Fkernel%2Flinux-rpi.git 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 Cc: drm-intel-fixes@lists.freedesktop.org Fixes: bffce907d640 ("drm/i915: abstract i2c bit banging fallback in gmbus xfer") Signed-off-by: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/1457366220-29409-2-git-send-email-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula --- diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index deb8282..52fbe53 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -664,6 +664,12 @@ int intel_setup_gmbus(struct drm_device *dev) bus->adapter.algo = &gmbus_algorithm; + /* + * We wish to retry with bit banging + * after a timed out GMBUS attempt. + */ + bus->adapter.retries = 1; + /* By default use a conservative clock rate */ bus->reg0 = pin | GMBUS_RATE_100KHZ;