[Intel-gfx] [PATCH] drm/i915: Correct the IOSF Dev_FN field for IOSF transfers

Shobhit Kumar shobhit.kumar at linux.intel.com
Mon Feb 9 03:16:01 PST 2015


On 02/05/2015 10:44 PM, Ville Syrjälä wrote:
> On Thu, Feb 05, 2015 at 05:10:56PM +0530, Shobhit Kumar wrote:
>> As per the specififcation, the SB_DevFn is the PCI_DEVFN of the target
>> device and not the source. So PCI_DEVFN(2,0) is not correct. Further the
>> port ID should be enough to identify devices unless they are MFD. The
>> SB_DevFn was intended to remove ambiguity in case of these MFD devices.
>>
>> For non MFD devices the recommendation for the target device IP was to
>> ignore these fields, but not all of them followed the recommendation.
>> Some like CCK ignore these fields and hence PCI_DEVFN(2, 0) works and so
>> does PCI_DEVFN(0, 0) as it works for DPIO. The issue came to light because
>> of GPIONC which was not getting programmed correctly with PCI_DEVFN(2, 0).
>> It turned out that this did not follow the recommendation and expected 0
>> in this field.
>>
>> In general the recommendation is to use SB_DevFn as PCI_DEVFN(0, 0) for
>> all devices except target PCI devices.
>>
>> Signed-off-by: Shobhit Kumar <shobhit.kumar at intel.com>
> 
> Yep, confirmed on my BYT that GPIONC doesn't like the devfn 2.0. On BSW
> GPIONC seems to have become more relaxed and accepts devfn 2.0 as well.
> 
> I also tried to poke at all the other sideband units we care about and
> they appear to work just as well with 2.0 and 0.0. But being consistent
> seems like a good idea, so 0.0 it is for everyone.
> 
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Thanks Ville. Daniel this needs more testing/reviews to merge ?

Regards
Shobhit

> 
>> ---
>>  drivers/gpu/drm/i915/intel_sideband.c | 26 +++++++++++++-------------
>>  1 file changed, 13 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_sideband.c b/drivers/gpu/drm/i915/intel_sideband.c
>> index 01d841e..731b10a 100644
>> --- a/drivers/gpu/drm/i915/intel_sideband.c
>> +++ b/drivers/gpu/drm/i915/intel_sideband.c
>> @@ -82,7 +82,7 @@ u32 vlv_punit_read(struct drm_i915_private *dev_priv, u8 addr)
>>  	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
>>  
>>  	mutex_lock(&dev_priv->dpio_lock);
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_PUNIT,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
>>  			SB_CRRDDA_NP, addr, &val);
>>  	mutex_unlock(&dev_priv->dpio_lock);
>>  
>> @@ -94,7 +94,7 @@ void vlv_punit_write(struct drm_i915_private *dev_priv, u8 addr, u32 val)
>>  	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
>>  
>>  	mutex_lock(&dev_priv->dpio_lock);
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_PUNIT,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_PUNIT,
>>  			SB_CRWRDA_NP, addr, &val);
>>  	mutex_unlock(&dev_priv->dpio_lock);
>>  }
>> @@ -103,7 +103,7 @@ u32 vlv_bunit_read(struct drm_i915_private *dev_priv, u32 reg)
>>  {
>>  	u32 val = 0;
>>  
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_BUNIT,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_BUNIT,
>>  			SB_CRRDDA_NP, reg, &val);
>>  
>>  	return val;
>> @@ -111,7 +111,7 @@ u32 vlv_bunit_read(struct drm_i915_private *dev_priv, u32 reg)
>>  
>>  void vlv_bunit_write(struct drm_i915_private *dev_priv, u32 reg, u32 val)
>>  {
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_BUNIT,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_BUNIT,
>>  			SB_CRWRDA_NP, reg, &val);
>>  }
>>  
>> @@ -122,7 +122,7 @@ u32 vlv_nc_read(struct drm_i915_private *dev_priv, u8 addr)
>>  	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
>>  
>>  	mutex_lock(&dev_priv->dpio_lock);
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_NC,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_NC,
>>  			SB_CRRDDA_NP, addr, &val);
>>  	mutex_unlock(&dev_priv->dpio_lock);
>>  
>> @@ -132,56 +132,56 @@ u32 vlv_nc_read(struct drm_i915_private *dev_priv, u8 addr)
>>  u32 vlv_gpio_nc_read(struct drm_i915_private *dev_priv, u32 reg)
>>  {
>>  	u32 val = 0;
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_GPIO_NC,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_GPIO_NC,
>>  			SB_CRRDDA_NP, reg, &val);
>>  	return val;
>>  }
>>  
>>  void vlv_gpio_nc_write(struct drm_i915_private *dev_priv, u32 reg, u32 val)
>>  {
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_GPIO_NC,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_GPIO_NC,
>>  			SB_CRWRDA_NP, reg, &val);
>>  }
>>  
>>  u32 vlv_cck_read(struct drm_i915_private *dev_priv, u32 reg)
>>  {
>>  	u32 val = 0;
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_CCK,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_CCK,
>>  			SB_CRRDDA_NP, reg, &val);
>>  	return val;
>>  }
>>  
>>  void vlv_cck_write(struct drm_i915_private *dev_priv, u32 reg, u32 val)
>>  {
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_CCK,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_CCK,
>>  			SB_CRWRDA_NP, reg, &val);
>>  }
>>  
>>  u32 vlv_ccu_read(struct drm_i915_private *dev_priv, u32 reg)
>>  {
>>  	u32 val = 0;
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_CCU,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_CCU,
>>  			SB_CRRDDA_NP, reg, &val);
>>  	return val;
>>  }
>>  
>>  void vlv_ccu_write(struct drm_i915_private *dev_priv, u32 reg, u32 val)
>>  {
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_CCU,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_CCU,
>>  			SB_CRWRDA_NP, reg, &val);
>>  }
>>  
>>  u32 vlv_gps_core_read(struct drm_i915_private *dev_priv, u32 reg)
>>  {
>>  	u32 val = 0;
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_GPS_CORE,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_GPS_CORE,
>>  			SB_CRRDDA_NP, reg, &val);
>>  	return val;
>>  }
>>  
>>  void vlv_gps_core_write(struct drm_i915_private *dev_priv, u32 reg, u32 val)
>>  {
>> -	vlv_sideband_rw(dev_priv, PCI_DEVFN(2, 0), IOSF_PORT_GPS_CORE,
>> +	vlv_sideband_rw(dev_priv, PCI_DEVFN(0, 0), IOSF_PORT_GPS_CORE,
>>  			SB_CRWRDA_NP, reg, &val);
>>  }
>>  
>> -- 
>> 1.9.1
> 


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