Re: [PATCH v5 15/36] drm/bridge: analogix_dp: Fix incorrect usage of enhanced mode

[Archit Taneja]

On Saturday 10 March 2018 03:53 AM, Enric Balletbo i Serra wrote:
> From: zain wang <wzz@xxxxxxxxxxxxxx>
>
> Enhanced mode is required by the eDP 1.2 specification, and not doing it
> early could result in a period of time where we have a link transmitting
> idle packets without it. Since there is no reason to disable it, we just
> enable it at the beginning of link training and then keep it on all the
> time.

Reviewed-by: Archit Taneja <architt@xxxxxxxxxxxxxx>

Thanks,
Archit

> Cc: Tomasz Figa <tfiga@xxxxxxxxxxxx>
> Signed-off-by: zain wang <wzz@xxxxxxxxxxxxxx>
> Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
> Signed-off-by: Thierry Escande <thierry.escande@xxxxxxxxxxxxx>
> Reviewed-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
> Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> ---
>
>   drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index 6cbde8473f58..1eed35f9eb8d 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -281,6 +281,8 @@ static int analogix_dp_link_start(struct analogix_dp_device *dp)
>   	retval = drm_dp_dpcd_write(&dp->aux, DP_LINK_BW_SET, buf, 2);
>   	if (retval < 0)
>   		return retval;
> +	/* set enhanced mode if available */
> +	analogix_dp_set_enhanced_mode(dp);
>   
>   	/* Set TX pre-emphasis to minimum */
>   	for (lane = 0; lane < lane_count; lane++)
> @@ -593,8 +595,6 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)
>   		dev_dbg(dp->dev, "fast link training %s\n",
>   			dp->fast_train_enable ? "supported" : "unsupported");
>   
> -		/* set enhanced mode if available */
> -		analogix_dp_set_enhanced_mode(dp);
>   		dp->link_train.lt_state = FINISHED;
>   
>   		return 0;
> @@ -940,8 +940,6 @@ static int analogix_dp_commit(struct analogix_dp_device *dp)
>   	}
>   
>   	analogix_dp_enable_scramble(dp, 1);
> -	analogix_dp_enable_rx_to_enhanced_mode(dp, 1);
> -	analogix_dp_enable_enhanced_mode(dp, 1);
>   
>   	analogix_dp_init_video(dp);
>   	ret = analogix_dp_config_video(dp);