[PATCH v3] drm/exynos: calculate vrefresh instead of use a fixed value

[Tobias Jakobi]

Gustavo Padovan wrote:
> From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> 
> When mode's vrefresh is zero we should ask DRM core to calculate vrefresh
> for us so we can get the correct value instead of relying on fixed value
> defined in a macro. But if vrefresh is still zero we should fail the
> update.
This works better for me:
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
index dc834b8..26e8ae4 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
@@ -346,11 +346,16 @@ static bool fimd_mode_fixup(struct exynos_drm_crtc
*crtc,
 static void fimd_commit(struct exynos_drm_crtc *crtc)
 {
        struct fimd_context *ctx = crtc->ctx;
-       struct drm_display_mode *mode = &crtc->base.mode;
+       struct drm_display_mode *mode;
        struct fimd_driver_data *driver_data = ctx->driver_data;
        void *timing_base = ctx->regs + driver_data->timing_base;
        u32 val, clkdiv;

+       if (crtc->base.state)
+               mode = &crtc->base.state->adjusted_mode;
+       else
+               mode = &crtc->base.mode;
+
        if (ctx->suspended)
                return;

Otherwise I get an oops (nullptr deref) on boot, so 'state' is probably
not initialized yet at this point.


With best wishes,
Tobias Jakobi


> 
> Suggested-by: Daniel Stone <daniels at collabora.com>
> Signed-off-by: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_fimd.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> index 9819fa6..3f9646d 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
> @@ -42,7 +42,6 @@
>   * CPU Interface.
>   */
>  
> -#define FIMD_DEFAULT_FRAMERATE 60
>  #define MIN_FB_WIDTH_FOR_16WORD_BURST 128
>  
>  /* position control register for hardware window 0, 2 ~ 4.*/
> @@ -329,7 +328,9 @@ static bool fimd_mode_fixup(struct exynos_drm_crtc *crtc,
>  		struct drm_display_mode *adjusted_mode)
>  {
>  	if (adjusted_mode->vrefresh == 0)
> -		adjusted_mode->vrefresh = FIMD_DEFAULT_FRAMERATE;
> +		adjusted_mode->vrefresh = drm_mode_vrefresh(mode);
> +	if (adjusted_mode->vrefresh == 0)
> +		return false;
>  
>  	return true;
>  }
> @@ -427,7 +428,7 @@ static void fimd_commit(struct exynos_drm_crtc *crtc)
>  	if (ctx->driver_data->has_clksel)
>  		val |= VIDCON0_CLKSEL_LCD;
>  
> -	clkdiv = fimd_calc_clkdiv(ctx, mode);
> +	clkdiv = fimd_calc_clkdiv(ctx, &crtc->base.state->adjusted_mode);
>  	if (clkdiv > 1)
>  		val |= VIDCON0_CLKVAL_F(clkdiv - 1) | VIDCON0_CLKDIR;
>  
>