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

[David Heidelberg]

On 29/09/2026 11:51, Krzysztof Kozlowski wrote:
> On 29/09/2026 11:41, David Heidelberg wrote:
> > 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.
>
> OK, I went way too fast, that's correct part. But splitting fix is still
> just confusing. Backporting to stable is a different thing than fixing
> issues.

Sure, I already droped the previous commit changing it for stable.

Btw. looking at gpiod_toggle_active_low(), would it make sense to do a series 
correcting panel reset logic? I see many panels keep "reset asserted" in the 
driver (but ofc not in the reality).

Thanks
David

> Best regards,
> Krzysztof