Hi Biju, On Wednesday, 28 November 2018 15:20:58 EET Biju Das wrote: > Hi all, > > On the past, I have tested vsp source on rcar gen2 koelsch board, using the > patches series below(Apart from the below patch series, I have enabled > "CONFIG_DRM_RCAR_VSP=y") > https://git.linuxtv.org/pinchartl/media.git/log/?h=drm/du/panels > > 1) [HACK] ARM: shmobile: r8a7791: Link the VSP1 and DU > 2) [HACK] v4l: vsp1: Disable UAPI for VSP1D > 3) [HACK] drm: rcar-du: Enable VSP source support for R8A7791 > > But on the latest renesas-dev branch looks like it is broken That doesn't surprise me too much as I don't actively maintain that code. For my information, what are your use cases ? Do you think this approach should be pursued and patches merged upstream ? The amount of work will be quite high though, given that it introduces a new userspace API, we will have to publish an open-source implementation in an X.org or Wayland driver. > The issue is kernel doesn't boot, if I connect display panel. Looks like it > is hanging in register_framebuffer. > > [ 5.344412] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013). > [ 5.364250] [drm] No driver support for vblank timestamp query. > > Have any one noticed this issue? This usually means that the kernel crashes with the console lock taken, preventing the oops from being printed. As a debugging hack you can comment out the locking calls in console_lock(), console_trylock() and console_unlock() (kernel/printk/printk.c). -- Regards, Laurent Pinchart
