[PATCH] drm/msm/dp: Remove INIT_SETUP delay

[Kuogee Hsieh]

On 1/17/2023 9:29 AM, Bjorn Andersson wrote:
> During initalization of the DisplayPort controller an EV_HPD_INIT_SETUP
> event is generated, but with a delay of 100 units. This delay existed to
> circumvent bug in the QMP combo PHY driver, where if the DP part was
> powered up before USB, the common properties would not be properly
> initialized - and USB wouldn't work.
>
> This issue was resolved in the recent refactoring of the QMP driver,
> so it's now possible to remove this delay.
>
> While there is still a timing dependency in the current implementation,
> test indicates that it's now possible to boot with an external display
> on USB Type-C and have the display power up, without disconnecting and
> reconnecting the cable.
>
> Signed-off-by: Bjorn Andersson <quic_bjorande at quicinc.com>
Reviewed-by: Kuogee Hsieh <quic_khsieh at quicinc.com>
> ---
>   drivers/gpu/drm/msm/dp/dp_display.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index db9783ffd5cf..bde1a7ce442f 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -1506,7 +1506,7 @@ void msm_dp_irq_postinstall(struct msm_dp *dp_display)
>   	dp = container_of(dp_display, struct dp_display_private, dp_display);
>   
>   	if (!dp_display->is_edp)
> -		dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 100);
> +		dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 0);
>   }
>   
>   bool msm_dp_wide_bus_available(const struct msm_dp *dp_display)