[PATCH] drm: panel: jd9365da: fix reset signal polarity in unprepare

[PATCH] drm: panel: jd9365da: fix reset signal polarity in unprepare

[Hugo Villeneuve]

From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

commit a8972d5a49b4 ("drm: panel: jd9365da-h3: fix reset signal polarity")
fixed reset signal polarity in jadard_dsi_probe() and jadard_prepare().

It was not done in jadard_unprepare() because of an incorrect assumption
about reset line handling in power off mode. After looking into the
datasheet, it now appears that before disabling regulators, the reset line
is deasserted first, and if reset_before_power_off_vcioo is true, then the
reset line is asserted.

Fix reset polarity by inverting gpiod_set_value() second argument in
in jadard_unprepare().

Fixes: 6b818c533dd8 ("drm: panel: Add Jadard JD9365DA-H3 DSI panel")
Fixes: 2b976ad760dc ("drm/panel: jd9365da: Support for kd101ne3-40ti MIPI-DSI panel")
Fixes: a8972d5a49b4 ("drm: panel: jd9365da-h3: fix reset signal polarity")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
---
 drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
index 7d68a8acfe2ea..eb0f8373258c3 100644
--- a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
+++ b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
@@ -129,11 +129,11 @@ static int jadard_unprepare(struct drm_panel *panel)
 {
 	struct jadard *jadard = panel_to_jadard(panel);
 
-	gpiod_set_value(jadard->reset, 1);
+	gpiod_set_value(jadard->reset, 0);
 	msleep(120);
 
 	if (jadard->desc->reset_before_power_off_vcioo) {
-		gpiod_set_value(jadard->reset, 0);
+		gpiod_set_value(jadard->reset, 1);
 
 		usleep_range(1000, 2000);
 	}

base-commit: 7adf8b1afc14832de099f9e178f08f91dc0dd6d0
-- 
2.39.5

Re: [PATCH] drm: panel: jd9365da: fix reset signal polarity in unprepare

[Neil Armstrong]

On 17/04/2025 21:55, Hugo Villeneuve wrote:
> From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> 
> commit a8972d5a49b4 ("drm: panel: jd9365da-h3: fix reset signal polarity")
> fixed reset signal polarity in jadard_dsi_probe() and jadard_prepare().
> 
> It was not done in jadard_unprepare() because of an incorrect assumption
> about reset line handling in power off mode. After looking into the
> datasheet, it now appears that before disabling regulators, the reset line
> is deasserted first, and if reset_before_power_off_vcioo is true, then the
> reset line is asserted.
> 
> Fix reset polarity by inverting gpiod_set_value() second argument in
> in jadard_unprepare().
> 
> Fixes: 6b818c533dd8 ("drm: panel: Add Jadard JD9365DA-H3 DSI panel")
> Fixes: 2b976ad760dc ("drm/panel: jd9365da: Support for kd101ne3-40ti MIPI-DSI panel")
> Fixes: a8972d5a49b4 ("drm: panel: jd9365da-h3: fix reset signal polarity")
> Cc: stable@vger.kernel.org
> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> ---
>   drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
> index 7d68a8acfe2ea..eb0f8373258c3 100644
> --- a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
> +++ b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c
> @@ -129,11 +129,11 @@ static int jadard_unprepare(struct drm_panel *panel)
>   {
>   	struct jadard *jadard = panel_to_jadard(panel);
>   
> -	gpiod_set_value(jadard->reset, 1);
> +	gpiod_set_value(jadard->reset, 0);
>   	msleep(120);
>   
>   	if (jadard->desc->reset_before_power_off_vcioo) {
> -		gpiod_set_value(jadard->reset, 0);
> +		gpiod_set_value(jadard->reset, 1);
>   
>   		usleep_range(1000, 2000);
>   	}
> 
> base-commit: 7adf8b1afc14832de099f9e178f08f91dc0dd6d0

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

Re: [PATCH] drm: panel: jd9365da: fix reset signal polarity in unprepare

[Neil Armstrong]

Hi,

On Thu, 17 Apr 2025 15:55:06 -0400, Hugo Villeneuve wrote:
> commit a8972d5a49b4 ("drm: panel: jd9365da-h3: fix reset signal polarity")
> fixed reset signal polarity in jadard_dsi_probe() and jadard_prepare().
> 
> It was not done in jadard_unprepare() because of an incorrect assumption
> about reset line handling in power off mode. After looking into the
> datasheet, it now appears that before disabling regulators, the reset line
> is deasserted first, and if reset_before_power_off_vcioo is true, then the
> reset line is asserted.
> 
> [...]

Thanks, Applied to https://gitlab.freedesktop.org/drm/misc/kernel.git (drm-misc-fixes)

[1/1] drm: panel: jd9365da: fix reset signal polarity in unprepare
      https://gitlab.freedesktop.org/drm/misc/kernel/-/commit/095c8e61f4c71cd4630ee11a82e82cc341b38464

-- 
Neil