Re: [PATCH] drm/stm: ltdc: reset controller to avoid partial refresh

From: Philippe CORNU
Date: Fri Apr 05 2019 - 12:31:40 EST




On 4/3/19 11:24 AM, Yannick Fertrà wrote:
> Display controller reset must be done as soon as possible after enable
> the clock to avoid partial refresh on screen.
>
> Signed-off-by: Yannick Fertrà <yannick.fertre@xxxxxx>
> ---
> drivers/gpu/drm/stm/ltdc.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> index 32fd6a3..7bbe61c 100644
> --- a/drivers/gpu/drm/stm/ltdc.c
> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -1134,6 +1134,12 @@ int ltdc_load(struct drm_device *ddev)
> return -ENODEV;
> }
>
> + if (!IS_ERR(rstc)) {
> + reset_control_assert(rstc);
> + usleep_range(10, 20);
> + reset_control_deassert(rstc);
> + }
> +
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> ldev->regs = devm_ioremap_resource(dev, res);
> if (IS_ERR(ldev->regs)) {
> @@ -1156,12 +1162,6 @@ int ltdc_load(struct drm_device *ddev)
> }
> }
>
> - if (!IS_ERR(rstc)) {
> - reset_control_assert(rstc);
> - usleep_range(10, 20);
> - reset_control_deassert(rstc);
> - }
> -

Dear Yannick,
Thank you for your patch,

Acked-by: Philippe Cornu <philippe.cornu@xxxxxx>

Philippe :)

> /* Disable interrupts */
> reg_clear(ldev->regs, LTDC_IER,
> IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
>