Commit 5e7222a3 authored by Douglas Anderson's avatar Douglas Anderson Committed by Linus Walleij
Browse files

drm/panel-simple: Undo enable if HPD never asserts 



If the HPD signal never asserts in panel_simple_prepare() and we
return an error, we should unset the enable GPIO and disable the
regulator to make it consistent for the caller.

At the moment I have some hardware where HPD sometimes doesn't assert.
Obviously that needs to be debugged, but this patch makes it so that
if I add a retry that I can make things work.

Fixes: 48834e60 ("drm/panel-simple: Support hpd-gpios for delaying prepare()")
Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210115144345.v2.1.I33fcbd64ab409cfe4f9491bf449f51925a4d3281@changeid
parent 429fc6f9

drivers/gpu/drm/panel/panel-simple.c

+9 −2
Original line number Diff line number Diff line
@@ -406,7 +406,7 @@ static int panel_simple_prepare(struct drm_panel *panel) 
		if (IS_ERR(p->hpd_gpio)) {

			err = panel_simple_get_hpd_gpio(panel->dev, p, false);

			if (err)

				return err;

				goto error;

		}



		err = readx_poll_timeout(gpiod_get_value_cansleep, p->hpd_gpio,
@@ -418,13 +418,20 @@ static int panel_simple_prepare(struct drm_panel *panel) 
		if (err) {

			dev_err(panel->dev,

				"error waiting for hpd GPIO: %d\n", err);

			return err;

			goto error;

		}

	}



	p->prepared_time = ktime_get();



	return 0;



error:

	gpiod_set_value_cansleep(p->enable_gpio, 0);

	regulator_disable(p->supply);

	p->unprepared_time = ktime_get();



	return err;

}



static int panel_simple_enable(struct drm_panel *panel)