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authorVille Syrjälä <ville.syrjala@linux.intel.com>2016-03-07 17:56:57 +0200
committerJani Nikula <jani.nikula@intel.com>2016-03-11 10:23:28 +0200
commit0bbca274a31c2366414d8d3f95e03d1c4674d93f (patch)
treeafe4fe667610d628afd23905c5ecfb236f7ee846
parent2f791908a70e95768596f5bb9e6de4f441d7bf13 (diff)
drm/i915: Actually retry with bit-banging after GMBUS timeoutdrm-intel-fixes-2016-03-11
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>
-rw-r--r--drivers/gpu/drm/i915/intel_i2c.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index deb8282c26d8..52fbe530fc9e 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;

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