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

From: Philip Chen
Date: Thu Oct 21 2021 - 17:07:14 EST


Hi Doug,

On Mon, Oct 18, 2021 at 1:43 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
>
> 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.
> */
>
Thanks for the review.
Added the comment in v2.
PTAL.

> 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>