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

[David Heidelberg <david@ixit.cz>]

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@linaro.org>
>>>> Signed-off-by: David Heidelberg <david@ixit.cz>
>>>> ---
>>>>    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