[PATCH 6.1 195/473] drm/panel: atna33xc20: Fix unbalanced regulator in the case HPD doesnt assert

Greg Kroah-Hartman
2024-06-06T14:15:15Z

From: Douglas Anderson <dianders@chromium.org>

[ Upstream commit 5e842d55bad7794823a50f24fd645b58f2ef93ab ]

When the atna33xc20 driver was first written the resume code never
returned an error. If there was a problem waiting for HPD it just
printed a warning and moved on. This changed in response to review
feedback [1] on a future patch but I accidentally didn't account for
rolling back the regulator enable in the error cases. Do so now.

[1] https://lore.kernel.org/all/5f3cf3a6-1cc2-63e4-f76b-4ee686764705@linaro.org/

Fixes: 3b5765df375c ("drm/panel: atna33xc20: Take advantage of wait_hpd_asserted() in struct drm_dp_aux")
Acked-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240313-homestarpanel-regulator-v1-1-b8e3a336da12@chromium.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../gpu/drm/panel/panel-samsung-atna33xc20.c | 22 +++++++++++--------
1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
index 8fa15321c22f4..5b698514957cf 100644
--- a/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
+++ b/drivers/gpu/drm/panel/panel-samsung-atna33xc20.c
@@ -109,19 +109,17 @@ static int atana33xc20_resume(struct device *dev)
if (hpd_asserted < 0)
ret = hpd_asserted;

- if (ret)
+ if (ret) {
dev_warn(dev, "Error waiting for HPD GPIO: %d\n", ret);
-
- return ret;
- }
-
- if (p->aux->wait_hpd_asserted) {
+ goto error;
+ }
+ } else if (p->aux->wait_hpd_asserted) {
ret = p->aux->wait_hpd_asserted(p->aux, HPD_MAX_US);

- if (ret)
+ if (ret) {
dev_warn(dev, "Controller error waiting for HPD: %d\n", ret);
-
- return ret;
+ goto error;
+ }
}

/*
@@ -133,6 +131,12 @@ static int atana33xc20_resume(struct device *dev)
* right times.
*/
return 0;
+
+error:
+ drm_dp_dpcd_set_powered(p->aux, false);
+ regulator_disable(p->supply);
+
+ return ret;
}

static int atana33xc20_disable(struct drm_panel *panel)
--
2.43.0