Re: [RESEND PATCH v3 4/6] drm/ingenic: Set DMA descriptor chain register when starting CRTC

[Christophe Branchereau <cbranchereau@gmail.com>]

Reviewed-by: Christophe Branchereau <cbranchereau@gmail.com>

On Tue, Oct 26, 2021 at 8:13 PM Paul Cercueil <paul@crapouillou.net> wrote:
>
> Setting the DMA descriptor chain register in the probe function has been
> fine until now, because we only ever had one descriptor per foreground.
>
> As the driver will soon have real descriptor chains, and the DMA
> descriptor chain register updates itself to point to the current
> descriptor being processed, this register needs to be reset after a full
> modeset to point to the first descriptor of the chain.
>
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
> ---
>  drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
> index 5dbeca0f8f37..cbc76cede99e 100644
> --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
> +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
> @@ -186,6 +186,10 @@ static void ingenic_drm_crtc_atomic_enable(struct drm_crtc *crtc,
>
>         regmap_write(priv->map, JZ_REG_LCD_STATE, 0);
>
> +       /* Set address of our DMA descriptor chain */
> +       regmap_write(priv->map, JZ_REG_LCD_DA0, dma_hwdesc_addr(priv, 0));
> +       regmap_write(priv->map, JZ_REG_LCD_DA1, dma_hwdesc_addr(priv, 1));
> +
>         regmap_update_bits(priv->map, JZ_REG_LCD_CTRL,
>                            JZ_LCD_CTRL_ENABLE | JZ_LCD_CTRL_DISABLE,
>                            JZ_LCD_CTRL_ENABLE);
> --
> 2.33.0
>