Re: drm/exynos: Add atomic modesetting support

[Gustavo Padovan <gustavo@padovan.org>]

Hi Tobias,

2015-05-15 Tobias Jakobi <tjakobi@math.uni-bielefeld.de>:

> Hello,
> 
> I did another run with drm.debug=0xff and also tried to figure out where the
> div-by-zero comes from.
> 
> The only division I see is in fimd_calc_clkdiv() (which is called by
> fimd_commit()). So it looks like 'ideal_clk' is zero when calling
> DIV_ROUND_UP().
> 
> 'htotal' and 'vtotal' can't be zero, since this is checked early in
> fimd_commit(). So 'vrefresh' has to be zero. Maybe this helps?

What is is the output when you run with this patch:

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
index 12ab80c..f5d215d 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
@@ -310,6 +310,8 @@ static u32 fimd_calc_clkdiv(struct fimd_context *ctx,
        unsigned long ideal_clk = mode->htotal * mode->vtotal * mode->vrefresh;
        u32 clkdiv;
 
+       DRM_DEBUG_KMS("vrefresh %d\n", mode->vrefresh);
+
        if (ctx->i80_if) {
                /*
                 * The frame done interrupt should be occurred prior to the
@@ -328,6 +330,7 @@ static bool fimd_mode_fixup(struct exynos_drm_crtc *crtc,
                const struct drm_display_mode *mode,
                struct drm_display_mode *adjusted_mode)
 {
+       DRM_DEBUG_KMS("vrefresh %d\n", adjusted_mode->vrefresh);
        if (adjusted_mode->vrefresh == 0)
                adjusted_mode->vrefresh = FIMD_DEFAULT_FRAMERATE;