1. 04 May, 2015 1 commit
    • Daniel Vetter's avatar
      drm/vblank: Fixup and document timestamp update/read barriers · 99264a61
      Daniel Vetter authored
      This was a bit too much cargo-culted, so lets make it solid:
      - vblank->count doesn't need to be an atomic, writes are always done
        under the protection of dev->vblank_time_lock. Switch to an unsigned
        long instead and update comments. Note that atomic_read is just a
        normal read of a volatile variable, so no need to audit all the
        read-side access specifically.
      
      - The barriers for the vblank counter seqlock weren't complete: The
        read-side was missing the first barrier between the counter read and
        the timestamp read, it only had a barrier between the ts and the
        counter read. We need both.
      
      - Barriers weren't properly documented. Since barriers only work if
        you have them on boths sides of the transaction it's prudent to
        reference where the other side is. To avoid duplicating the
        write-side comment 3 times extract a little store_vblank() helper.
        In that helper also assert that we do indeed hold
        dev->vblank_time_lock, since in some cases the lock is acquired a
        few functions up in the callchain.
      
      Spotted while reviewing a patch from Chris Wilson to add a fastpath to
      the vblank_wait ioctl.
      
      v2: Add comment to better explain how store_vblank works, suggested by
      Chris.
      
      v3: Peter noticed that as-is the 2nd smp_wmb is redundant with the
      implicit barrier in the spin_unlock. But that can only be proven by
      auditing all callers and my point in extracting this little helper was
      to localize all the locking into just one place. Hence I think that
      additional optimization is too risky.
      
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Cc: Mario Kleiner <mario.kleiner.de@gmail.com>
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: Michel Dänzer <michel@daenzer.net>
      Cc: Peter Hurley <peter@hurleysoftware.com>
      Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
      Reviewed-and-tested-by: default avatarMario Kleiner <mario.kleiner.de@gmail.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
      99264a61
  2. 20 Apr, 2015 2 commits
    • Josef Holzmayr's avatar
      DRM: Don't re-poll connector for disconnect · a3c6d686
      Josef Holzmayr authored
      DRM probe should not repoll a connector if it is already
      connected and the DRM_CONNECTOR_POLL_DISCONNECT flag is not set.
      Signed-off-by: default avatarJosef Holzmayr <holzmayr@rsi-elektrotechnik.de>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      a3c6d686
    • Todd Previte's avatar
      drm: Fix for DP CTS test 4.2.2.5 - I2C DEFER handling · 396aa445
      Todd Previte authored
      For test 4.2.2.5 to pass per the Link CTS Core 1.2 rev1.1 spec, the source
      device must attempt at least 7 times to read the EDID when it receives an
      I2C defer. The normal DRM code makes only 7 retries, regardless of whether
      or not the response is a native defer or an I2C defer. Test 4.2.2.5 fails
      since there are native defers interspersed with the I2C defers which
      results in less than 7 EDID read attempts.
      
      The solution is to add the numer of defers to the retry counter when an I2C
      DEFER is returned such that another read attempt will be made. This situation
      should normally only occur in compliance testing, however, as a worse case
      real-world scenario, it would result in 13 attempts ( 6 native defers, 7 I2C
      defers) for a single transaction to complete. The net result is a slightly
      slower response to an EDID read that shouldn't significantly impact overall
      performance.
      
      V2:
      - Added a check on the number of I2C Defers to limit the number
        of times that the retries variable will be decremented. This
        is to address review feedback regarding possible infinite loops
        from misbehaving sink devices.
      V3:
      - Fixed the limit value to 7 instead of 8 to get the correct retry
        count.
      - Combined the increment of the defer count into the if-statement
      V4:
      - Removed i915 tag from subject as the patch is not i915-specific
      V5:
      - Updated the for-loop to add the number of i2c defers to the retry
        counter such that the correct number of retry attempts will be
        made
      Signed-off-by: default avatarTodd Previte <tprevite@gmail.com>
      Cc: dri-devel@lists.freedesktop.org
      Reviewed-by: default avatarPaulo Zanoni <paulo.r.zanoni@intel.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      396aa445
  3. 16 Apr, 2015 2 commits
  4. 14 Apr, 2015 2 commits
    • John Hunter's avatar
      drm: fix trivial typo mistake · 2b1193d5
      John Hunter authored
      Signed-off-by: default avatarJohn Hunter <zhjwpku@gmail.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      2b1193d5
    • Matt Roper's avatar
      drm: Make integer overflow checking cover universal cursor updates (v2) · 3968be94
      Matt Roper authored
      Our legacy SetPlane updates perform integer overflow checking on a
      plane's destination rectangle in drm_mode_setplane(), and atomic updates
      handled as part of a drm_atomic_state transaction do the same checking
      in drm_atomic_plane_check().  However legacy cursor updates that get
      routed through universal plane interfaces may bypass this overflow
      checking if the driver's .update_plane is serviced by the transitional
      plane helpers rather than the full atomic plane helpers.
      
      Move the check for destination rectangle integer overflow from the
      drm_mode_setplane() to __setplane_internal() so that it also covers
      cursor operations.
      
      This fixes an issue first noticed with i915 commit:
      
              commit ff42e093
              Author: Daniel Vetter <daniel.vetter@ffwll.ch>
              Date:   Mon Mar 2 16:35:20 2015 +0100
      
                  Revert "drm/i915: Switch planes from transitional helpers to full
                  atomic helpers"
      
      The above revert switched us from full atomic helpers back to the
      transitional helpers, and in doing so we lost the overflow checking here
      for universal cursor updates.  Even though such extreme cursor positions
      are unlikely to actually happen in the wild, we still don't want there
      to be a change of behavior when drivers switch from transitional helpers
      to full helpers.
      
      v2: Move check from setplane ioctl to setplane_internal rather than
          adding an additional copy of the checks to the transitional plane
          helpers.  (Daniel)
      
      Cc: Daniel Vetter <daniel@ffwll.ch>
      Testcase: igt/kms_cursor_crc
      Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84269Signed-off-by: default avatarMatt Roper <matthew.d.roper@intel.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      3968be94
  5. 13 Apr, 2015 4 commits
  6. 11 Apr, 2015 1 commit
  7. 07 Apr, 2015 9 commits
  8. 01 Apr, 2015 1 commit
  9. 31 Mar, 2015 6 commits
  10. 30 Mar, 2015 3 commits
  11. 29 Mar, 2015 7 commits
  12. 28 Mar, 2015 2 commits