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: 48834e6084f1 ("drm/panel-simple: Support hpd-gpios for delaying prepare()") Signed-off-by: Douglas Anderson dianders@chromium.org ---

drivers/gpu/drm/panel/panel-simple.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index 71ae200ac48a..b89394b44f43 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -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 +418,19 @@ 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); + + return err; }

static int panel_simple_enable(struct drm_panel *panel)