On Mon, Oct 24, 2016 at 3:12 AM, Daniel Vetter <daniel@xxxxxxxx> wrote: > On Mon, Oct 24, 2016 at 9:00 AM, Manasi Navare > <manasi.d.navare@xxxxxxxxx> wrote: >>> I guess we just need to do some additional work on top to make sure the >>> vblank ioctl can't see invalid state. Which would then again make upfront >>> link trainig possible ... >> >> Could you share some more details on what work would need to be done >> for vblank? Then I can investigate it a little bit more tomor during the day. > > So the trouble is that drm_irq.c is still from the old pre-kms days. > Which means it deals in int pipe instead of struct drm_crtc *, among > other things. But we can't simply switch over because some old drivers > (pre-kms ones) still depend upon that old code. Hence we need: > > 1. Duplicate most of the code in drm_irq.c into a new > drm_crtc_vblank.c, which is only used for kms drivers. Why duplicate all of this code? That seems a bit wasteful. Can't we just add the inverse of drm_crtc_pipe() (coincidentally, I also suggested we introduce this function in "drm: zte: add initial vou drm driver"), and use those to map between pipe and crtc where appropriate? The crtc locks could be acquired/dropped based on DRIVER_MODESET in drm_irq.c Unrelated to the vblank discussion: This functionality is pretty similar to what happens on suspend/resume. Any chance we can share? Sean > And in the > ioctl code have a DRIVER_MODESET check and either call the new kms > version (in drm_crtc_vblank.c) or the old one (still in drm_irq.c). > > 2. Convert the int pipe into a drm_crtc pointer in the new kms code. > For prettiness we could (try) to do that as much as possible. > > 3. Grab the drm_crtc->mutex in the ioctl code to block these races. > > -Daniel > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
