On Thu, Jun 16, 2016 at 8:09 AM, Jose Abreu <Jose.Abreu@xxxxxxxxxxxx> wrote: > Hi Daniel, > > Sorry to bother you again. I promise this is the last time :) > > On 15-06-2016 11:15, Daniel Vetter wrote: >> On Wed, Jun 15, 2016 at 11:48 AM, Jose Abreu <Jose.Abreu@xxxxxxxxxxxx> wrote: >>> On 15-06-2016 09:52, Daniel Vetter wrote: >>>> On Tue, Jun 14, 2016 at 1:19 PM, Jose Abreu <Jose.Abreu@xxxxxxxxxxxx> wrote: >>>>>> I assume that xilinx VDMA is the only way to feed pixel data into your >>>>>> display pipeline. Under that assumption: >>>>>> >>>>>> drm_plane should map to Xilinx VDMA, and the drm_plane->drm_crtc link >>>>>> would represent the dma channel. With atomic you can subclass >>>>>> drm_plane/crtc_state structures to store all the runtime configuration in >>>>>> there. >>>>>> >>>>>> The actual buffer itsel would be represented by a drm_framebuffer, which >>>>>> either wraps a shmem gem or a cma gem object. >>>>>> >>>>>> If you want to know about the callbacks used by the atomic helpers to push >>>>>> out plane updates, look at the hooks drm_atomic_helper_commit_planes() >>>>>> (and the related functions, see kerneldoc) calls. >>>>>> >>>>>> I hope this helps a bit more. >>>>>> -Daniel >>>>> Thanks a lot! With your help I was able to implement all the >>>>> needed logic. Sorry to bother you but I have one more question. >>>>> Right now I can initialize and configure the vdma correctly but I >>>>> can only send one frame. I guess when the dma completes >>>>> transmission I need to ask drm for a new frame, right? Because >>>>> the commit function starts the vdma correctly but then the dma >>>>> halts waiting for a new descriptor. >>>> DRM has a continuous scanout model, i.e. when userspace doesn't give >>>> you a new frame you're supposed to keep scanning out the current one. >>>> So you need to rearm your upload code with the same drm_framebuffer if >>>> userspace hasn't supplied a new one since the last time before the >>>> vblank period starts. >>>> >>>> This is different to v4l, where userspace has to supply each frame >>>> (and the kernel gets angry when there's not enough frames and signals >>>> an underrun of the queue). This is because drm is geared at desktops, >>>> and there it's perfectly normal to show the exact same frame for a >>>> long time. >>>> -Daniel >>> Thanks, I was thinking this was similar to v4l. I am now able to >>> send multiple frames so it is finally working! I have one little >>> implementation detail: The controller that I am using supports >>> deep color mode but I am using FB CMA helpers to create the >>> framebuffer and I've seen that the supported bpp in these helpers >>> only goes up to 32, right? Does this means that with these >>> helpers I can't use deep color? Can I implement this deep color >>> mode (48bpp) using a custom fb or do I also need custom gem >>> allocation functions (Right now I am using GEM CMA helpers)? >> Suprising the cma doesn't take pixel_format into account. If this >> really doesn't work, pls fix up the cma helpers, not roll your own >> copypasta ;-) >> >> Note that the fbdev emulation itself (maybe that's what threw you off) >> only supports legacy rgb formats up to 32bits. But native kms can >> support anything, we just might need to add the DRM_FOURCC codes for >> that. >> -Daniel > > So, I ended up using 32bits and everything is working fine! I > tested using [1] and [2] but now I have kind of a dumb question: > I want to use the new driver that I created as a secondary output > of my desktop so that I can play videos using mplayer but I am > not being able to do this. If I check in my linux settings only > one display is being detected, although in /dev/dri the two video > cards are present (the native one and the one I added). Does the > driver needs something additional to do this or is it only in my > X configuration? I tried editing this configuration but still > doesn't work. I believe that because my driver is not being > probed at runtime the display is not being created by X. Is this > correct? Have a look at https://nouveau.freedesktop.org/wiki/Optimus/ specifically the section titled "Using outputs on discrete GPU". If you're still having trouble, please provide an Xorg log. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
