[PATCH v1] drm/msm/dp: do not reinitialize phy unless retry during link training

[Stephen Boyd]

Quoting Kuogee Hsieh (2023-08-08 15:19:50)
> 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 at quicinc.com>
> ---

Reviewed-by: Stephen Boyd <swboyd at chromium.org>