[PATCH 1/2] drm/dp: add extended receiver capability field present bit

Rodrigo Vivi rodrigo.vivi at intel.com
Thu Jul 19 21:04:06 UTC 2018


On Thu, Jul 19, 2018 at 01:35:48PM -0700, matthew.s.atwood at intel.com wrote:
> From: Matt Atwood <matthew.s.atwood at intel.com>
> 
> This bit was added to DP Training Aux RD interval sometime between DP
> 1.2 and DP 1.3.

I understand that some 1.2 version that I had here that caused
all the trouble around XXX 1.2, but since one of the requests
from Jani was to clarify and remove the 1.2 I went there to check
again and that version that I had here doesn't work anymore.

So I went to VESA site and checked and it is not there on latest
official 1.2a.
It is there on 1.3.

This message should be updated now.

> Via description of the spec this field indicates the
> panels true capabilities are described in DPCD address space 02200h
> through 022FFh.
> 
> v2: version comment update
> 
> Signed-off-by: Matt Atwood <matthew.s.atwood at intel.com>
> ---
>  include/drm/drm_dp_helper.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index c01564991a9f..28061c69136b 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -123,8 +123,9 @@
>  # define DP_FRAMING_CHANGE_CAP		    (1 << 1)
>  # define DP_DPCD_DISPLAY_CONTROL_CAPABLE     (1 << 3) /* edp v1.2 or higher */
>  
> -#define DP_TRAINING_AUX_RD_INTERVAL         0x00e   /* XXX 1.2? */
> -# define DP_TRAINING_AUX_RD_MASK            0x7F    /* XXX 1.2? */
> +#define DP_TRAINING_AUX_RD_INTERVAL             0x00e   /* XXX 1.2? */
> +# define DP_TRAINING_AUX_RD_MASK                0x7F    /* XXX 1.3? */
> +# define DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT (1 << 7)/* XXX 1.3? */

Since that is the official and clear thing we should now remove XXX
and add /* DP 1.3 */

I believe that during 1.2 times we might had seen a lot of those
bizare cases when one version has it and another doesn't, and probably
that was the cause of many /* XXX 1.2? */ we have on the driver.

But please note that there is no XXX for 1.3 and 1.4, since things
are very clear and organized.

>  
>  #define DP_ADAPTER_CAP			    0x00f   /* 1.2 */
>  # define DP_FORCE_LOAD_SENSE_CAP	    (1 << 0)
> -- 
> 2.17.1
> 


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