| Message ID | 1457366220-29409-2-git-send-email-ville.syrjala@linux.intel.com |
|---|---|
| State | Accepted |
| Commit | 8b1f165a4a8f64c28cf42d10e1f4d3b451dedc51 |
| Headers | show |
| Series |
"drm/i915: GMBUS fixes and whatnot"
( rev:
1
)
in
Intel GFX |
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;
On Mon, 07 Mar 2016, ville.syrjala@linux.intel.com wrote: > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > 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. I think I must have confused this with the dp aux i2c adapter retries which does get initialized to 3. Meh. Reviewed-by: Jani Nikula <jani.nikula@intel.com> > > 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> > --- > drivers/gpu/drm/i915/intel_i2c.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > 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;
On Mon, Mar 07, 2016 at 07:06:37PM +0200, Jani Nikula wrote: > On Mon, 07 Mar 2016, ville.syrjala@linux.intel.com wrote: > > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > > > 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. > > I think I must have confused this with the dp aux i2c adapter retries > which does get initialized to 3. Meh. > > Reviewed-by: Jani Nikula <jani.nikula@intel.com> Patch pushed to dinq. Thanks for the review. > > > > > 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> > > --- > > drivers/gpu/drm/i915/intel_i2c.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > 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; > > -- > Jani Nikula, Intel Open Source Technology Center