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

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

On 5/27/2014 5:02 PM, Damien Lespiau wrote:
> On Fri, May 23, 2014 at 09:39:28PM +0530, Shobhit Kumar wrote:
>> It seems by default the VBT has MIPI configuration block as well. The
>> Generic driver will assume always MIPI if MIPI configuration block is found.
>> This is causing probelm when actually there is eDP. Fix this by looking
>> into general definition block which will have device configurations. From here
>> we can figure out what is the LFP type and initialize MIPI only if MIPI
>> is found.
>>
>> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_drv.h      |  2 ++
>>   drivers/gpu/drm/i915/intel_bios.c    | 20 +++++++++++++++++++-
>>   drivers/gpu/drm/i915/intel_display.c |  4 +++-
>>   3 files changed, 24 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 8e78703..5a5225b 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1229,7 +1229,9 @@ struct intel_vbt_data {
>>   	} backlight;
>>
>>   	/* MIPI DSI */
>> +	int is_mipi;
>
> There's a "feature" bitfield near the start of the structure, I think
> you should add that field there and maybe rename it to has_mipi.

will do.

>
>>   	struct {
>> +		u16 port;
>
> We store the port but never use it, is it needed?

Just wanted to store as we might want to use later while enabling. 
Shouldn't harm ? In fact we have a need to enable PORT C internally.

>
>>   		u16 panel_id;
>>   		struct mipi_config *config;
>>   		struct mipi_pps_data *pps;
>> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
>> index 6b65096..b825c80 100644
>> --- a/drivers/gpu/drm/i915/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/intel_bios.c
>> @@ -1059,6 +1059,20 @@ parse_device_mapping(struct drm_i915_private *dev_priv,
>>   			/* skip the device block if device type is invalid */
>>   			continue;
>>   		}
>> +
>> +#define MIPI_PORT_A	0x15
>> +#define MIPI_PORT_B	0x16
>> +#define MIPI_PORT_C	0x17
>> +#define MIPI_PORT_D	0x18
>
> These should go with the other valid defines for dvo_port in
> intel_bios.h and be renamed to match, eg. DEVICE_PORT_MIPI_A.

Will do

>
> Also this is not what I have in my copy of the VBT documentation, I have
> (in decimal) MIPI PORT_A = 11, .., PORT_D = 14

What I have say 21..24. Again this is the problem we need to fix.

>
>> +		if (p_child->common.dvo_port >= MIPI_PORT_A && p_child->common.dvo_port <= MIPI_PORT_D) {
>> +			/* check the device type and confirm its MIPI */
>> +			if (p_child->common.device_type & DEVICE_TYPE_MIPI_OUTPUT) {
>> +				DRM_DEBUG_KMS("Found MIPI as LFP\n");
>> +				dev_priv->vbt.is_mipi = 1;
>> +				dev_priv->vbt.dsi.port = p_child->common.dvo_port;
>> +			}
>> +		}
>> +
>>   		child_dev_ptr = dev_priv->vbt.child_dev + count;
>>   		count++;
>>   		memcpy((void *)child_dev_ptr, (void *)p_child,
>> @@ -1230,7 +1244,11 @@ intel_parse_bios(struct drm_device *dev)
>>   	parse_device_mapping(dev_priv, bdb);
>>   	parse_driver_features(dev_priv, bdb);
>>   	parse_edp(dev_priv, bdb);
>> -	parse_mipi(dev_priv, bdb);
>> +
>> +	/* parse MIPI blocks only if LFP type is MIPI */
>> +	if (dev_priv->vbt.is_mipi)
>> +		parse_mipi(dev_priv, bdb);
>
> Let's put that check inside parse_mipi so we don't break the symetry of
> those parse_* calls.

Will do.

>
>> +
>>   	parse_ddi_ports(dev_priv, bdb);
>>
>>   	if (bios)
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index 3da73ef..a55fa41 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -11151,7 +11151,9 @@ static void intel_setup_outputs(struct drm_device *dev)
>>   			}
>>   		}
>>
>> -		intel_dsi_init(dev);
>> +		/* There is no detection method for MIPI so rely on VBT */
>> +		if (dev_priv->vbt.is_mipi)
>> +			intel_dsi_init(dev);
>
> Can we have that check inside intel_dsi_init() so we don't have to do it
> for every platform with DSI?

Will do

regards
Shobhit

>
>>   	} else if (SUPPORTS_DIGITAL_OUTPUTS(dev)) {
>>   		bool found = false;
>>
>> --
>> 1.8.3.2
>>