On Fri, Jan 26, 2018 at 02:16:56PM +0100, Thierry Escande wrote:
> From: zain wang <w...@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.
>
> Cc: Tomasz Figa <tf...@chromium.org>
> Signed-off-by: zain wang <w...@rock-chips.com>
> Signed-off-by: Douglas Anderson <diand...@chromium.org>
> Signed-off-by: Sean Paul <seanp...@chromium.org>
> Signed-off-by: Thierry Escande <thierry.esca...@collabora.com>
> Reviewed-by: Andrzej Hajda <a.ha...@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 e7ab871e62b5..bee0f7aa5c23 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -599,7 +599,7 @@ 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);
>
> @@ -643,20 +643,6 @@ 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;
> @@ -997,6 +983,22 @@ 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;
> @@ -1039,8 +1041,16 @@ 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;
You could probably flip this with psr_enable and just return on error instead of
flipping psr_enable back. Not a big deal either way.
Sean
>
> return ret;
> }
> --
> 2.14.1
>
--
Sean Paul, Software Engineer, Google / Chromium OS
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