RE: [PATCH] drm/edid : cache edid range limits in drm connector

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

On Wed, 04 May 2016, "Prosyak, Vitaly" <Vitaly.Prosyak@amd.com> wrote:
> We are going to use min/max vertical refresh rate when enter/exit to
> the dynamic refresh rate mode ,it is known as 'freesync', enter/exit
> to full screen games.

As Daniel said, we should see the patch using them too. It's hard to say
whether this is the right thing to do otherwise.

BR,
Jani.

> Right , we may have a helper function which extracts these properties and store wherever need it.
> But this an alternative solution  with additional helper adds some code duplication into drm_edid.c  since the case already present in the code:
> case 0x01: /* just the ranges, no formula */ Also these values are parsed during each mode enumeration.
>
> Why I put into connector: 
> Drm connector have already similar items from EDID: drm_tile_group ,etc...
>
> Vitaly
> -----Original Message-----.
>
> From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of Daniel Vetter
> Sent: Tuesday, May 03, 2016 4:24 PM
> To: Prosyak, Vitaly
> Cc: dri-devel@lists.freedesktop.org
> Subject: Re: [PATCH] drm/edid : cache edid range limits in drm connector
>
> On Tue, May 03, 2016 at 11:05:24AM -0400, Vitaly Prosyak wrote:
>> Cache in drm connector the edid range limits properties:
>> min/max vertical refresh rates and max pixel clock.
>> It would be used when enter to drr mode.
>> 
>> Signed-off-by: Vitaly Prosyak <vitaly.prosyak@amd.com>
>
> Where's the patches that will use this? It might make sense to instead have some helper functions to compute these values, so that drivers can store them wherever they want/need. But impossible to tell without the users of this stuff.
> -Daniel
>
>> ---
>>  drivers/gpu/drm/drm_edid.c | 11 +++++++++++
>>  include/drm/drm_crtc.h     |  5 +++++
>>  2 files changed, 16 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c 
>> index 04cb487..7e49962 100644
>> --- a/drivers/gpu/drm/drm_edid.c
>> +++ b/drivers/gpu/drm/drm_edid.c
>> @@ -2190,6 +2190,17 @@ do_inferred_modes(struct detailed_timing *timing, void *c)
>>  							  timing);
>>  		break;
>>  	case 0x01: /* just the ranges, no formula */
>> +		closure->connector->min_vfreq = range->min_vfreq;
>> +		closure->connector->max_vfreq = range->max_vfreq;
>> +		if (closure->edid->revision >= 4) {
>> +			if ((range->flags & 0x03) == 0x3)
>> +				closure->connector->min_vfreq += 255;
>> +			if (range->flags & 0x02)
>> +				closure->connector->max_vfreq += 255;
>> +		}
>> +		closure->connector->max_pixel_clock_khz =
>> +			range_pixel_clock(closure->edid, (u8 *)timing);
>> +		break;
>>  	default:
>>  		break;
>>  	}
>> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h index
>> c5b4b81..85fc554 100644
>> --- a/include/drm/drm_crtc.h
>> +++ b/include/drm/drm_crtc.h
>> @@ -1230,6 +1230,11 @@ struct drm_connector {
>>  	uint8_t num_h_tile, num_v_tile;
>>  	uint8_t tile_h_loc, tile_v_loc;
>>  	uint16_t tile_h_size, tile_v_size;
>> +
>> +	/*EDID range limits for drr*/
>> +	int min_vfreq ;
>> +	int max_vfreq ;
>> +	int max_pixel_clock_khz;
>>  };
>>  
>>  /**
>> --
>> 1.9.1
>> 
>> _______________________________________________
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>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Jani Nikula, Intel Open Source Technology Center
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