Re: [PATCH v2 06/11] drm/panel: s6e3ha8: Correct the polarity logic within

[David Heidelberg]

On 29/09/2026 09:45, Krzysztof Kozlowski wrote:
> On Thu, Sep 24, 2026 at 04:01:34PM +0200, David Heidelberg wrote:
> > The reset was introduced with wrong polarity. Correct for the future
> > compatibles and keep current with reverted logic.
> >
> > Old DTs keep GPIO_ACTIVE_HIGH and are fixed up via
> > gpiod_toggle_active_low() on the deprecated compatible.
> >
> > Assisted-by: LLM
> > Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> > Signed-off-by: David Heidelberg <david@xxxxxxx>
> > ---
> >   drivers/gpu/drm/panel/panel-samsung-s6e3ha8.c | 23 +++++++++++++++++++----
> >   1 file changed, 19 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e3ha8.c b/drivers/gpu/drm/panel/panel-samsung-s6e3ha8.c
> > index 5e1e997b83b36..99290913de69a 100644
> > --- a/drivers/gpu/drm/panel/panel-samsung-s6e3ha8.c
> > +++ b/drivers/gpu/drm/panel/panel-samsung-s6e3ha8.c
> > @@ -20,16 +20,17 @@
> >   #include "panel-samsung-dsi.h"
> >   
> >   struct s6e3ha8_desc {
> >   	const struct drm_panel_funcs *funcs;
> >   	const struct drm_display_mode *mode;
> >   	unsigned long mode_flags;
> >   	const struct regulator_bulk_data *supplies;
> >   	unsigned int num_supplies;
> > +	bool broken_reset_polarity;
> >   };
> >   
> >   struct s6e3ha8 {
> >   	struct drm_panel panel;
> >   	struct mipi_dsi_device *dsi;
> >   	const struct s6e3ha8_desc *desc;
> >   	struct drm_dsc_config dsc;
> >   	struct gpio_desc *reset_gpio;
> > @@ -62,22 +63,22 @@ static int s6e3ha8_unprepare(struct drm_panel *panel)
> >   {
> >   	struct s6e3ha8 *priv = to_s6e3ha8(panel);
> >   
> >   	return regulator_bulk_disable(priv->desc->num_supplies, priv->supplies);
> >   }
> >   
> >   static void s6e3ha8_amb577px01_wqhd_reset(struct s6e3ha8 *priv)
> >   {
> > -	gpiod_set_value_cansleep(priv->reset_gpio, 1);
> > -	usleep_range(5000, 6000);
> >   	gpiod_set_value_cansleep(priv->reset_gpio, 0);
> >   	usleep_range(5000, 6000);
> >   	gpiod_set_value_cansleep(priv->reset_gpio, 1);
> >   	usleep_range(5000, 6000);
> > +	gpiod_set_value_cansleep(priv->reset_gpio, 0);
>
> This breaks all users and this usage of ABI was already released.

See the gpiod_toggle_active_low() usage later in the patch which keep the logic 
for the original compatible as intended.

David

...
+	if (priv->desc->broken_reset_polarity)
+		gpiod_toggle_active_low(priv->reset_gpio);
+

> NAK
>
> > +	usleep_range(5000, 6000);
> >   }
> >   
> >   static int s6e3ha8_amb577px01_wqhd_on(struct s6e3ha8 *priv)
> >   {
> >   	struct mipi_dsi_device *dsi = priv->dsi;
> >   	struct mipi_dsi_multi_context ctx = { .dsi = dsi };
> >   
> >   	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
> > @@ -203,17 +204,17 @@ static int s6e3ha8_amb577px01_wqhd_prepare(struct drm_panel *panel)
> >   	ret = regulator_bulk_enable(priv->desc->num_supplies, priv->supplies);
> >   	if (ret < 0)
> >   		return ret;
> >   	mipi_dsi_msleep(&ctx, 120);
> >   	s6e3ha8_amb577px01_wqhd_reset(priv);
> >   
> >   	ret = s6e3ha8_amb577px01_wqhd_on(priv);
> >   	if (ret < 0) {
> > -		gpiod_set_value_cansleep(priv->reset_gpio, 0);
> > +		gpiod_set_value_cansleep(priv->reset_gpio, 1);
>
> No, you just changed it!

> Implement correct and logical fixes, not half-baked fix which is
> immediately wrong.
>
> Best regards,
> Krzysztof