Re: [PATCH v5 23/36] drm/bridge: analogix_dp: Move fast link training detect to set_bridge

Archit Taneja
2018-03-14T06:52:13Z

On Saturday 10 March 2018 03:53 AM, Enric Balletbo i Serra wrote:
> From: zain wang <wzz@rock-chips.com>
>
> It's too early to detect fast link training, if other step after it
> failed, we will set fast_link flag to 1, and retry set_bridge again. In
> this case we will power down and power up panel power supply, and we
> will do fast link training since we have set fast_link flag to 1. In
> fact, we should do full link training now, not the fast link training.
> So we should move the fast link detection at the end of set_bridge.

Is it possible to re-write this commit message? It's a bit hard to
follow.

Thanks,
Archit

>
> Cc: Tomasz Figa <tfiga@chromium.org>
> Signed-off-by: zain wang <wzz@rock-chips.com>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>
> Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>
> drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 42 +++++++++++++---------
> 1 file changed, 26 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index d76e1652b1fd..37b16643f14c 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -601,7 +601,7 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)
> {
> int lane, lane_count, retval;
> u32 reg;
> - u8 link_align, link_status[2], adjust_request[2], spread;
> + u8 link_align, link_status[2], adjust_request[2];
>
> usleep_range(400, 401);
>
> @@ -645,20 +645,6 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)
> dev_dbg(dp->dev, "final lane count = %.2x\n",
> dp->link_train.lane_count);
>
> - retval = drm_dp_dpcd_readb(&dp->aux, DP_MAX_DOWNSPREAD,
> - &spread);
> - if (retval != 1) {
> - dev_err(dp->dev, "failed to read downspread %d\n",
> - retval);
> - dp->fast_train_enable = false;
> - } else {
> - dp->fast_train_enable =
> - (spread & DP_NO_AUX_HANDSHAKE_LINK_TRAINING) ?
> - true : false;
> - }
> - dev_dbg(dp->dev, "fast link training %s\n",
> - dp->fast_train_enable ? "supported" : "unsupported");
> -
> dp->link_train.lt_state = FINISHED;
>
> return 0;
> @@ -996,6 +982,22 @@ static irqreturn_t analogix_dp_irq_thread(int irq, void *arg)
> return IRQ_HANDLED;
> }
>
> +static int analogix_dp_fast_link_train_detection(struct analogix_dp_device *dp)
> +{
> + int ret;
> + u8 spread;
> +
> + ret = drm_dp_dpcd_readb(&dp->aux, DP_MAX_DOWNSPREAD, &spread);
> + if (ret != 1) {
> + dev_err(dp->dev, "failed to read downspread %d\n", ret);
> + return ret;
> + }
> + dp->fast_train_enable = !!(spread & DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
> + dev_dbg(dp->dev, "fast link training %s\n",
> + dp->fast_train_enable ? "supported" : "unsupported");
> + return 0;
> +}
> +
> static int analogix_dp_commit(struct analogix_dp_device *dp)
> {
> int ret;
> @@ -1038,8 +1040,16 @@ static int analogix_dp_commit(struct analogix_dp_device *dp)
> if (ret)
> return ret;
>
> - if (dp->psr_enable)
> + if (dp->psr_enable) {
> ret = analogix_dp_enable_sink_psr(dp);
> + if (ret)
> + return ret;
> + }
> +
> + /* Check whether panel supports fast training */
> + ret = analogix_dp_fast_link_train_detection(dp);
> + if (ret)
> + dp->psr_enable = false;
>
> return ret;
> }
>