Re: [PATCH v6 2/2] drm/bridge: Add Lontium LT9611C(EX/UXD) MIPI DSI to HDMI driver

[Krzysztof Kozlowski <krzk@kernel.org>]

On 25/06/2026 15:14, Sunyun Yang wrote:
> Krzysztof Kozlowski <krzk@kernel.org> 于2026年6月25日周四 20:54写道：
>>
>> On 08/05/2026 15:40, syyang@lontium.com wrote:
>>> +
>>> +static void lt9611c_reset(struct lt9611c *lt9611c)
>>> +{
>>> +     gpiod_set_value_cansleep(lt9611c->reset_gpio, 1);
>>> +     msleep(20);
>>> +
>>> +     gpiod_set_value_cansleep(lt9611c->reset_gpio, 0);
>>> +     msleep(20);
>>> +
>>> +     gpiod_set_value_cansleep(lt9611c->reset_gpio, 1);
>>
>> This is just plain wrong. Why do you assert, then de-assert and then
>> finally assert AGAIN the reset leaving the device in powerdown stage?
>>
> I am using software to emulate the hardware RESET button on our EVB.
> When the hardware RESET button is pressed while our chip is running,
> the signal level changes from HIGH to LOW and then back to HIGH.
> 
> Of course, we can also use the following:
> static void lt9611c_reset(struct lt9611c *lt9611c)
> {
>     gpiod_set_value_cansleep(lt9611c->reset_gpio, 0);
>     msleep(50);
>     gpiod_set_value_cansleep(lt9611c->reset_gpio, 1);
>     msleep(20);
> }

Makes no sense either and you just did not get the point and did not
answer my question. I asked WHY you leave asserted. Answer "we emulate"
is just plain wrong.

So again please answer:

Why do you leave device with reset asserted?

Best regards,
Krzysztof