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

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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>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210115144345.v2.1.I33fcbd64ab409cfe4f9491bf449f51925a4d3281@changeid
This commit is contained in:
Douglas Anderson 2021-01-15 14:44:16 -08:00 committed by Linus Walleij
parent 429fc6f955
commit 5e7222a367
1 changed files with 9 additions and 2 deletions
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11
drivers/gpu/drm/panel/panel-simple.c
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@ -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)