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| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2016-03-07 16:56:57 +0100 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2016-03-11 09:23:28 +0100 |
| commit | 0bbca274a31c2366414d8d3f95e03d1c4674d93f (patch) | |
| tree | afe4fe667610d628afd23905c5ecfb236f7ee846 /drivers | |
| parent | drm/i915: Fix bogus dig_port_map[] assignment for pre-HSW (diff) | |
| download | linux-0bbca274a31c2366414d8d3f95e03d1c4674d93f.tar.xz linux-0bbca274a31c2366414d8d3f95e03d1c4674d93f.zip | |
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_i2c.c | 6 |
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; |