1. 23 Feb, 2015 6 commits
    • Daniel Vetter's avatar
      drm: WARN if drm_handle_vblank is called errornously · ee3c7795
      Daniel Vetter authored
      KMS drivers are in full control of their irq and vblank handling, if
      they get a vblank interrupt before drm_vblank_init or after
      drm_vblank_cleanup that's just a driver bug.
      
      For ums driver there's only r128 and radeon which support vblank, and
      they call drm_vblank_init in their driver load functions. Which again
      means that userspace can do whatever it wants with interrupt, vblank
      structures will always be there.
      
      So this should never happen, let's catch driver issues with a WARN_ON.
      Motivated by some discussions with Imre.
      
      v2: Use WARN_ON_ONCE as suggested by Imre.
      
      Cc: Imre Deak <imre.deak@intel.com>
      Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
      Acked-by: default avatarDave Airlie <airlied@redhat.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
      ee3c7795
    • Daniel Vetter's avatar
      drm/irq: Don't call ->get_vblank_counter directly from irq_uninstall/cleanup · 3bff93d6
      Daniel Vetter authored
      The pipe might already have been shut down, and then it's not a good
      idea to call hw accessor functions. Instead use the same logic as
      drm_vblank_off which has all the necessary checks to avoid troubles or
      inconsistency.
      
      Noticed by Imre while reviewing my patches to remove some sanity
      checks from ->get_vblank_counter.
      
      v2: Try harder. disable_and_save can still access the vblank stuff
      when vblank->enabled isn't set. It has to, since vlbank irq could be
      disable but the pipe is still on when being called from
      drm_vblank_off. But we still want to use that code for more code
      sharing. So add a check for vblank->enabled on top - if that's not set
      we shouldn't have anyone waiting for the vblank. If we have that's a
      pretty serious bug.
      
      The other issue that Imre spotted is drm_vblank_cleanup. That code
      again calls disable_and_save and so suffers from the same issues. But
      really drm_irq_uninstall should have cleaned that all up, so replace
      the code with WARN_ON. Note that we can't delete the timer cleanup
      since drivers aren't required to use drm_irq_install/uninstall, but
      can do their own irq handling.
      
      v3: Make it clear that all that gunk in drm_irq_uninstall is really
      just bandaids for UMS races between the irq/vblank code. In UMS
      userspace is in control of enabling/disabling interrupts in general
      and vblanks specifically.
      
      v4: Imre observed that KMS drivers all call drm_vblank_cleanup before
      drm_irq_uninstall (as they should), so again the code in there is dead
      for KMS (due to dev->num_crtcs == 0 after drm_vblank_cleanup). Or
      should be, so only WARN for KMS - with UMS userspace could try to do
      evil things.
      
      v5: After more discussion on irc we've gone back to v3: the
      del_timer_sync is required in all cases in drm_vblank_cleanup, but
      let's restrict the WARN_ON to kms drivers only. Imre was also
      concerned that bad things could happen without the disable_and_save
      call. But we immediately free vblank structures afterwards which makes
      the save useless. And drm_handle_vblank has a check for dev->num_crtcs
      to avoid surprises with ums.
      
      Cc: Imre Deak <imre.deak@intel.com>
      Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
      Acked-by: default avatarDave Airlie <airlied@redhat.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
      3bff93d6
    • Daniel Vetter's avatar
      drm/i915: Switch to drm_crtc variants of vblank functions · 1e3feefd
      Daniel Vetter authored
      Where possible right now. Just a small step towards nirvana ...
      
      v2: git add. Uggh. Noticed by Imre.
      
      Cc: Imre Deak <imre.deak@intel.com>
      Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
      1e3feefd
    • Daniel Vetter's avatar
      drm/i915: Flatten DRIVER_MODESET checks in i915_irq.c · f3a5c3f6
      Daniel Vetter authored
      UMS is no more!
      
      Cc: Imre Deak <imre.deak@intel.com>
      Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
      f3a5c3f6
    • Daniel Vetter's avatar
      drm/i915: Drop pipe_enable checks in vblank funcs · 1efa2e35
      Daniel Vetter authored
      With Ville's rework to use drm_crtc_vblank_on/off the core will take
      care of rejecting drm_vblank_get calls when the pipe is off. Also the
      core won't call the get_vblank_counter hooks in that case either. And
      since we've dropped ums support recently we can now remove these
      hacks, yay!
      
      Noticed while trying to answer questions Laurent had about how the new
      atomic helpers work.
      
      Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
      Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
      1efa2e35
    • Daniel Vetter's avatar
      drm/irq: Add drm_crtc_vblank_reset · 9625604c
      Daniel Vetter authored
      At driver load we need to tell the vblank code about the state of the
      pipes, so that the logic around reject vblank_get when the pipe is off
      works correctly.
      
      Thus far i915 used drm_vblank_off, but one of the side-effects of it
      is that it also saves the vblank counter. And for that it calls down
      into the ->get_vblank_counter hook. Which isn't really a good idea
      when the pipe is off for a few reasons:
      - With runtime pm the register might not respond.
      - If the pipe is off some datastructures might not be around or
        unitialized.
      
      The later is what blew up on gen3: We look at intel_crtc->config to
      compute the vblank counter, and for a disabled pipe at boot-up that's
      just not there. Thus far this was papered over by a check for
      intel_crtc->active, but I want to get rid of that (since it's fairly
      race, vblank hooks are called from all kinds of places).
      
      So prep for that by adding a _reset functions which only does what we
      really need to be done at driver load: Mark the vblank pipe as off,
      but don't do any vblank counter saving or event flushing - neither of
      that is required.
      
      v2: Clarify the code flow slightly as suggested by Ville.
      
      v3: Fix kerneldoc spelling, spotted by Laurent.
      
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
      Cc: Imre Deak <imre.deak@intel.com>
      Reviewed-by: Imre Deak <imre.deak@intel.com> (v2)
      Acked-by: default avatarDave Airlie <airlied@redhat.com>
      Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
      9625604c
  2. 13 Feb, 2015 34 commits