LKML Archive on
help / color / mirror / Atom feed
* [BUG, bisect] drm/i915: mouse pointer lags and overshoots
@ 2015-01-17 10:06 Jeremiah Mahler
  2015-01-18 13:57 ` Andrey Skvortsov
  2015-01-19  9:08 ` [Intel-gfx] " Ville Syrjälä
  0 siblings, 2 replies; 12+ messages in thread
From: Jeremiah Mahler @ 2015-01-17 10:06 UTC (permalink / raw)
  To: Matt Roper
  Cc: Daniel Vetter, Jani Nikula, David Airlie, Alex Deucher,
	Dave Airlie, Ander Conselvan de Oliveira, linux-kernel,
	intel-gfx, dri-devel

Matt, all,

Commit ea2c67bb4aff introduces a bug which causes the mouse to move in a
very unusual way, as if it has a lot of inertia.  It will lag behind and
then overshoot the expected position.

I reproduced this bug on all my machines which use the drm/i915 drivers
and it affects all forms of mouse pointers including both touchpads and
usb mice.  The patch is present in linux-next 20150116.

  commit ea2c67bb4affa84080c616920f3899f123786e56
  Author: Matt Roper <>
  Date:   Tue Dec 23 10:41:52 2014 -0800
      drm/i915: Move to atomic plane helpers (v9)
      Switch plane handling to use the atomic plane helpers.  This means that
      rather than provide our own implementations of .update_plane() and
      .disable_plane(), we expose the lower-level check/prepare/commit/cleanup
      entrypoints and let the DRM core implement update/disable for us using
      those entrypoints.
      The other main change that falls out of this patch is that our
      drm_plane's will now always have a valid plane->state that contains the
      relevant plane state (initial state is allocated at plane creation).
      The base drm_plane_state pointed to holds the requested source/dest
      coordinates, and the subclassed intel_plane_state holds the adjusted
      values that our driver actually uses.
       - Renamed file from intel_atomic.c to intel_atomic_plane.c (Daniel)
       - Fix a copy/paste comment mistake (Bob)
       - Use prepare/cleanup functions that we've already factored out
       - Use newly refactored pre_commit/commit/post_commit to avoid sleeping
         during vblank evasion
       - Rebase to latest di-nightly requires adding an 'old_state' parameter
         to atomic_update;
       - Must have botched a rebase somewhere and lost some work.  Restore
         state 'dirty' flag to let begin/end code know which planes to
         run the pre_commit/post_commit hooks for.  This would have actually
         shown up as broken in the next commit rather than this one.
       - Squash kerneldoc patch into this one.
       - Previous patches have now already taken care of most of the
         infrastructure that used to be in this patch.  All we're adding here
         now is some thin wrappers.
       - Check return of intel_plane_duplicate_state() for allocation
       - Drop unused drm_plane_state -> intel_plane_state cast.  (Ander)
       - Squash in actual transition to plane helpers.  Significant
         refactoring earlier in the patchset has made the combined
         prep+transition much easier to swallow than it was in earlier
         iterations. (Ander)
       - s/track_fbs/disabled_planes/ in the atomic crtc flags.  The only fb's
         we need to update frontbuffer tracking for are those on a plane about
         to be disabled (since the atomic helpers never call prepare_fb() when
         disabling a plane), so the new name more accurately describes what
         we're actually tracking.
      Testcase: igt/kms_plane
      Testcase: igt/kms_universal_plane
      Testcase: igt/kms_cursor_crc
      Signed-off-by: Matt Roper <>
      Reviewed-by: Ander Conselvan de Oliveira <>
      Signed-off-by: Daniel Vetter <>

- Jeremiah Mahler

^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2015-01-24 20:27 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-01-17 10:06 [BUG, bisect] drm/i915: mouse pointer lags and overshoots Jeremiah Mahler
2015-01-18 13:57 ` Andrey Skvortsov
2015-01-19  9:08 ` [Intel-gfx] " Ville Syrjälä
2015-01-19 10:51   ` Daniel Vetter
2015-01-19 11:04     ` Chris Wilson
2015-01-19 16:40       ` Matt Roper
2015-01-19 20:43         ` Chris Wilson
2015-01-20  5:48         ` Daniel Vetter
2015-01-24  6:57           ` Jeremiah Mahler
2015-01-24 11:24             ` Daniel Vetter
2015-01-24 20:27               ` Jeremiah Mahler
2015-01-19 11:14     ` Ville Syrjälä

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).