On Tue, Aug 08, 2023 at 03:19:50PM -0700, Kuogee Hsieh wrote:
> DP PHY re-initialization done using dp_ctrl_reinitialize_mainlink() will
> cause PLL unlocked initially and then PLL gets locked at the end of
> initialization. PLL_UNLOCKED interrupt will fire during this time if the
> interrupt mask is enabled.
> However currently DP driver link training implementation incorrectly
> re-initializes PHY unconditionally during link training as the PHY was
> already configured in dp_ctrl_enable_mainlink_clocks().
>
> Fix this by re-initializing the PHY only if the previous link training
> failed.
>
> [drm:dp_aux_isr] *ERROR* Unexpected DP AUX IRQ 0x01000000 when not busy
>
> Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
> Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/30
> Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
This fixes the above warning and avoids the unnecessary PHY power-off
and power-on during boot of the ThinkPad X13s:
Reviewed-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
Tested-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
I guess this one should go to stable as well:
Cc: stable@xxxxxxxxxxxxxxx # 5.10
Is anyone planning on getting this fixed in 6.6-rc? I noticed that this
one still hasn't shown up linux-next.
> ---
> drivers/gpu/drm/msm/dp/dp_ctrl.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> index a7a5c7e..77a8d93 100644
> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
> @@ -1774,13 +1774,6 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
> return rc;
>
> while (--link_train_max_retries) {
> - rc = dp_ctrl_reinitialize_mainlink(ctrl);
> - if (rc) {
> - DRM_ERROR("Failed to reinitialize mainlink. rc=%d\n",
> - rc);
> - break;
> - }
> -
> training_step = DP_TRAINING_NONE;
> rc = dp_ctrl_setup_main_link(ctrl, &training_step);
> if (rc == 0) {
> @@ -1832,6 +1825,12 @@ int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl)
> /* stop link training before start re training */
> dp_ctrl_clear_training_pattern(ctrl);
> }
> +
> + rc = dp_ctrl_reinitialize_mainlink(ctrl);
> + if (rc) {
> + DRM_ERROR("Failed to reinitialize mainlink. rc=%d\n", rc);
> + break;
> + }
> }
>
> if (ctrl->link->sink_request & DP_TEST_LINK_PHY_TEST_PATTERN)
Johan
