Re: [v3] drm/i915: Detect if MIPI panel based on VBT and initialize only if present

["Kumar, Shobhit" <shobhit.kumar@intel.com>]

On 5/27/2014 7:47 PM, Damien Lespiau wrote:
> Sorry to be such a bore but:
>
> On Tue, May 27, 2014 at 07:33:59PM +0530, Shobhit Kumar wrote:
>> --- a/drivers/gpu/drm/i915/intel_dsi.c
>> +++ b/drivers/gpu/drm/i915/intel_dsi.c
>> @@ -660,6 +660,10 @@ bool intel_dsi_init(struct drm_device *dev)
>>
>>   	DRM_DEBUG_KMS("\n");
>>
>> +	/* There is no detection method for MIPI so rely on VBT */
>> +	if (!dev_priv->vbt.has_mipi)
>> +		return false;
>> +
>
> Huum, if we can intel_dsi_init() on VLV, but we don't have a MIPI panel,
> shouldn't return true here? ie. "intel_dsi_init() was successful, we
> just don't have a MIPI panel.

This check just determines that the design has probably eDP and not MIPI 
panel attached. Assuming of course that on any design will have either 
eDP or MIPI as LFP. So I was checking in terms of the OEM design and not 
platform capability to have DSI.

In fact even in intel_dp_init when in edp_init_connector fails to read 
DPCD we return false. In fact why we really need to have a return value 
when we don't even check it and for example intel_dp_init is void 
intel_dp_init

Regards
Shobhit