Re: [PATCH v3 12/14] drm: bridge/analogix_dp: expand the delay time for hpd detect

[Jingoo Han]

On 2015. 8. 19., at PM 11:52, Yakir Yang <ykk@xxxxxxxxxxxxxx> wrote:
> 
> Some edp screen with no hpd signal would need some delay time
> to ensure that screen would be ready for work, so we can expand
> the delay time in hpd detect function, it works prefectly on my
> rk3288 sdk board.

Then, this delay has a dependency on the "rk3288 sdk" board.
Also, if the delay time is expanded, the booting time of some Exybos boards will be increased unnecessarily. :-(

So, please add new DT property such as 'hpd-delay' that can be added to board DT files.

If there is not that DT property in DT files, the default value '10' will written to a variable such as 'unsigned int hpd_delay'.
If there is the DT property in DT files, the delay value will written to the variable when parsing DT values
and will be used in analogix_dp_detect_hpd().

What I want to say is that there should not be harmful effect on the existing Exynos boards, due to unrelated reasons.

Best regards,
Jingoo Han

> Signed-off-by: Yakir Yang <ykk@xxxxxxxxxxxxxx>
> ---
> Changes in v3: None
> Changes in v2: None
> 
> drivers/gpu/drm/bridge/analogix_dp_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix_dp_core.c
> index 99870f7..75dd44a 100644
> --- a/drivers/gpu/drm/bridge/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix_dp_core.c
> @@ -68,7 +68,7 @@ static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
>            return 0;
> 
>        timeout_loop++;
> -        usleep_range(10, 11);
> +        usleep_range(100, 110);
>    }
> 
>    /*
> -- 
> 1.9.1
> 
> 
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