Re: [PATCH 1/3] drm/i915: turn the eDP VDD on for any i2c transactions

[Jani Nikula <jani.nikula@linux.intel.com>]

On the series,
Reviewed-by: Jani Nikula <jani.nikula@intel.com>


On Wed, 30 Oct 2013, Paulo Zanoni <przanoni@gmail.com> wrote:
> From: Paulo Zanoni <paulo.r.zanoni@intel.com>
>
> If the eDP output is disabled, then we try to use /dev/i2c-X file to
> do i2c transations, we get a WARN from intel_dp_check_edp() saying
> we're trying to do AUX communication with the panel off. So this
> commit reorganizes the code so we enable the VDD at
> intel_dp_i2c_aux_ch() instead of just the callers inside i915.ko.
>
> This fixes the i2c subtest from the pc8 test of intel-gpu-tools on
> machines that have eDP panels.
>
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 29 +++++++++++++++++------------
>  1 file changed, 17 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index b3cc333..05d0424 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -623,6 +623,7 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
>  	int reply_bytes;
>  	int ret;
>  
> +	ironlake_edp_panel_vdd_on(intel_dp);
>  	intel_dp_check_edp(intel_dp);
>  	/* Set up the command byte */
>  	if (mode & MODE_I2C_READ)
> @@ -665,7 +666,7 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
>  				      reply, reply_bytes);
>  		if (ret < 0) {
>  			DRM_DEBUG_KMS("aux_ch failed %d\n", ret);
> -			return ret;
> +			goto out;
>  		}
>  
>  		switch (reply[0] & AUX_NATIVE_REPLY_MASK) {
> @@ -676,7 +677,8 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
>  			break;
>  		case AUX_NATIVE_REPLY_NACK:
>  			DRM_DEBUG_KMS("aux_ch native nack\n");
> -			return -EREMOTEIO;
> +			ret = -EREMOTEIO;
> +			goto out;
>  		case AUX_NATIVE_REPLY_DEFER:
>  			/*
>  			 * For now, just give more slack to branch devices. We
> @@ -694,7 +696,8 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
>  		default:
>  			DRM_ERROR("aux_ch invalid native reply 0x%02x\n",
>  				  reply[0]);
> -			return -EREMOTEIO;
> +			ret = -EREMOTEIO;
> +			goto out;
>  		}
>  
>  		switch (reply[0] & AUX_I2C_REPLY_MASK) {
> @@ -702,22 +705,29 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
>  			if (mode == MODE_I2C_READ) {
>  				*read_byte = reply[1];
>  			}
> -			return reply_bytes - 1;
> +			ret = reply_bytes - 1;
> +			goto out;
>  		case AUX_I2C_REPLY_NACK:
>  			DRM_DEBUG_KMS("aux_i2c nack\n");
> -			return -EREMOTEIO;
> +			ret = -EREMOTEIO;
> +			goto out;
>  		case AUX_I2C_REPLY_DEFER:
>  			DRM_DEBUG_KMS("aux_i2c defer\n");
>  			udelay(100);
>  			break;
>  		default:
>  			DRM_ERROR("aux_i2c invalid reply 0x%02x\n", reply[0]);
> -			return -EREMOTEIO;
> +			ret = -EREMOTEIO;
> +			goto out;
>  		}
>  	}
>  
>  	DRM_ERROR("too many retries, giving up\n");
> -	return -EREMOTEIO;
> +	ret = -EREMOTEIO;
> +
> +out:
> +	ironlake_edp_panel_vdd_off(intel_dp, false);
> +	return ret;
>  }
>  
>  static int
> @@ -739,9 +749,7 @@ intel_dp_i2c_init(struct intel_dp *intel_dp,
>  	intel_dp->adapter.algo_data = &intel_dp->algo;
>  	intel_dp->adapter.dev.parent = intel_connector->base.kdev;
>  
> -	ironlake_edp_panel_vdd_on(intel_dp);
>  	ret = i2c_dp_aux_add_bus(&intel_dp->adapter);
> -	ironlake_edp_panel_vdd_off(intel_dp, false);
>  	return ret;
>  }
>  
> @@ -3498,7 +3506,6 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
>  	intel_dp_init_panel_power_sequencer_registers(dev, intel_dp,
>  						      &power_seq);
>  
> -	ironlake_edp_panel_vdd_on(intel_dp);
>  	edid = drm_get_edid(connector, &intel_dp->adapter);
>  	if (edid) {
>  		if (drm_add_edid_modes(connector, edid)) {
> @@ -3530,8 +3537,6 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
>  			fixed_mode->type |= DRM_MODE_TYPE_PREFERRED;
>  	}
>  
> -	ironlake_edp_panel_vdd_off(intel_dp, false);
> -
>  	intel_panel_init(&intel_connector->panel, fixed_mode);
>  	intel_panel_setup_backlight(connector);
>  
> -- 
> 1.8.3.1
>
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-- 
Jani Nikula, Intel Open Source Technology Center