Hello Alex, Alex Deucher wrote: > On Sat, Apr 30, 2016 at 5:37 PM, Tobias Jakobi > <tjakobi@xxxxxxxxxxxxxxxxxxxxx> wrote: >> Hello, >> >> while playing around with FIMD enabled, I noticed that when first using >> the device a zero division was triggered in fimd_calc_clkdiv(). I >> remembered that I had a similar issue some time ago. >> >> I added a stub fimd_atomic_check() which shows that vrefresh is zero >> when fimd_calc_clkdiv() is called. >> >> [ 164.059361] [drm:exynos_plane_mode_set] plane : offset_x/y(0,0), >> width/height(1366,768) >> [ 164.067175] [drm:fimd_atomic_check] xres=1366, yres=768, refresh=0, >> intl=0 >> [ 164.074198] [drm:drm_atomic_helper_check_planes] [CRTC:24:crtc-0] >> atomic driver check failed >> >> I went back to the git log and noticed that some time ago in >> 50bbfbffa5c894def440ce8157dfe53e60960d35 the fimd_mode_fixup() call was >> removed. >> >> I'm now wondering where exactly vrefresh is set to a sane value. As far >> as I can see of_get_videomode() is used to fetch the video mode from the >> DT, and drm_display_mode_from_videomode() is used to convert it. However >> vrefresh is nowhere set. >> >> So is something broken here, or am I missing something? >> > > There is no guarantee that vrefresh is actually set. I think the only > way to reliably get it is to call drm_mode_vrefresh(). Well, my impression from studying the code currently is that vrefresh is _never_ set. In particular the Exynos specific DRM code only ever reads vrefresh. I was just wondering how this is supposed to function at all. - Tobias > > > Alex > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
 |