Message ID | 20150518195101.GA18856@joana (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Hi, On Monday, May 18, 2015, Gustavo Padovan <gustavo@padovan.org> wrote: > Hi Tobias, > > 2015-05-15 Tobias Jakobi <tjakobi@math.uni-bielefeld.de <javascript:;>>: > > 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; > vrefresh can legitimately be zero, which makes this FIMD_DEFAULT_FRAMERATE assignment problematic rather than harmless. If it's zero, you can find a vrefresh value with drm_mode_vrefresh, which will calculate it for you. Cheers, Daniel
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;