6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
commit a8972d5a49b408248294b5ecbdd0a085e4726349 upstream.
In jadard_prepare() a reset pulse is generated with the following
statements (delays ommited for clarity):
gpiod_set_value(jadard->reset, 1); --> Deassert reset
gpiod_set_value(jadard->reset, 0); --> Assert reset for 10ms
gpiod_set_value(jadard->reset, 1); --> Deassert reset
However, specifying second argument of "0" to gpiod_set_value() means to
deassert the GPIO, and "1" means to assert it. If the reset signal is
defined as GPIO_ACTIVE_LOW in the DTS, the above statements will
incorrectly generate the reset pulse (inverted) and leave it asserted
(LOW) at the end of jadard_prepare().
Fix reset behavior by inverting gpiod_set_value() second argument
in jadard_prepare(). Also modify second argument to devm_gpiod_get()
in jadard_dsi_probe() to assert the reset when probing.
Do not modify it in jadard_unprepare() as it is already properly
asserted with "1", which seems to be the intended behavior.
Fixes: 6b818c533dd8 ("drm: panel: Add Jadard JD9365DA-H3 DSI panel")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240927135306.857617-1-hugo@xxxxxxxxxxx
Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240927135306.857617-1-hugo@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
+++ b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
@@ -109,13 +109,13 @@ static int jadard_prepare(struct drm_pan
if (jadard->desc->lp11_to_reset_delay_ms)
msleep(jadard->desc->lp11_to_reset_delay_ms);
- gpiod_set_value(jadard->reset, 1);
+ gpiod_set_value(jadard->reset, 0);
msleep(5);
- gpiod_set_value(jadard->reset, 0);
+ gpiod_set_value(jadard->reset, 1);
msleep(10);
- gpiod_set_value(jadard->reset, 1);
+ gpiod_set_value(jadard->reset, 0);
msleep(130);
ret = jadard->desc->init(jadard);
@@ -1130,7 +1130,7 @@ static int jadard_dsi_probe(struct mipi_
dsi->format = desc->format;
dsi->lanes = desc->lanes;
- jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+ jadard->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(jadard->reset)) {
DRM_DEV_ERROR(&dsi->dev, "failed to get our reset GPIO\n");
return PTR_ERR(jadard->reset);
