Re: [PATCH 1/2] drm/bridge: parade-ps8640: Enable runtime power management

From: Doug Anderson
Date: Mon Oct 18 2021 - 16:43:14 EST


Hi,

On Sat, Oct 16, 2021 at 9:57 AM Philip Chen <philipchen@xxxxxxxxxxxx> wrote:
>
> @@ -319,81 +345,70 @@ static void ps8640_bridge_poweron(struct ps8640 *ps_bridge)
> */
> msleep(200);
>
> - ret = regmap_read_poll_timeout(map, PAGE2_GPIO_H, status,
> - status & PS_GPIO9, 20 * 1000, 200 * 1000);
> -
> - if (ret < 0) {
> - DRM_ERROR("failed read PAGE2_GPIO_H: %d\n", ret);
> - goto err_regulators_disable;
> - }

Above the "msleep(200)" I see a comment that says "and then check the
MCU ready flag every 20ms". That probably refers to the code that
you're moving here. Maybe change the comment above the "msleep(200);"
to something like this if you like it:

/*
* Mystery 200 ms delay for the "MCU to be ready". It's unclear if
* this is truly necessary since the MCU will already signal that
* things are "good to go" by signaling HPD on "gpio 9". See
* ps8640_ensure_hpd(). For now we'll keep this mystery delay just in
* case.
*/

Other than that this looks good to me, which isn't really a surprise
since I was involved in helping with / reviewing early versions of
this change. In any case, I'm happy with:

Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>