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  1. 05 12月, 2015 7 次提交
    • M
      drm/radeon: Fixup hw vblank counter/ts for new drm_update_vblank_count() (v2) · 5b5561b3
      由 Mario Kleiner 提交于 
      commit 4dfd6486 "drm: Use vblank timestamps to guesstimate how many
vblanks were missed" introduced in Linux 4.4-rc1 makes the drm core
more fragile to drivers which don't update hw vblank counters and
vblank timestamps in sync with firing of the vblank irq and
essentially at leading edge of vblank.

This exposed a problem with radeon-kms/amdgpu-kms which do not
satisfy above requirements:

The vblank irq fires a few scanlines before start of vblank, but
programmed pageflips complete at start of vblank and
vblank timestamps update at start of vblank, whereas the
hw vblank counter increments only later, at start of vsync.

This leads to problems like off by one errors for vblank counter
updates, vblank counters apparently going backwards or vblank
timestamps apparently having time going backwards. The net result
is stuttering of graphics in games, or little hangs, as well as
total failure of timing sensitive applications.

See bug #93147 for an example of the regression on Linux 4.4-rc:

https://bugs.freedesktop.org/show_bug.cgi?id=93147

This patch tries to align all above events better from the
viewpoint of the drm core / of external callers to fix the problem:

1. The apparent start of vblank is shifted a few scanlines earlier,
so the vblank irq now always happens after start of this extended
vblank interval and thereby drm_update_vblank_count() always samples
the updated vblank count and timestamp of the new vblank interval.

To achieve this, the reporting of scanout positions by
radeon_get_crtc_scanoutpos() now operates as if the vblank starts
radeon_crtc->lb_vblank_lead_lines before the real start of the hw
vblank interval. This means that the vblank timestamps which are based
on these scanout positions will now update at this earlier start of
vblank.

2. The driver->get_vblank_counter() function will bump the returned
vblank count as read from the hw by +1 if the query happens after
the shifted earlier start of the vblank, but before the real hw increment
at start of vsync, so the counter appears to increment at start of vblank
in sync with the timestamp update.

3. Calls from vblank irq-context and regular non-irq calls are now
treated identical, always simulating the shifted vblank start, to
avoid inconsistent results for queries happening from vblank irq vs.
happening from drm_vblank_enable() or vblank_disable_fn().

4. The radeon_flip_work_func will delay mmio programming a pageflip until
the start of the real vblank iff it happens to execute inside the shifted
earlier start of the vblank, so pageflips now also appear to execute at
start of the shifted vblank, in sync with vblank counter and timestamp
updates. This to avoid some races between updates of vblank count and
timestamps that are used for swap scheduling and pageflip execution which
could cause pageflips to execute before the scheduled target vblank.

The lb_vblank_lead_lines "fudge" value is calculated as the size of
the display controllers line buffer in scanlines for the given video
mode: Vblank irq's are triggered by the line buffer logic when the line
buffer refill for a video frame ends, ie. when the line buffer source read
position enters the hw vblank. This means that a vblank irq could fire at
most as many scanlines before the current reported scanout position of the
crtc timing generator as the number of scanlines the line buffer can
maximally hold for a given video mode.

This patch has been successfully tested on a RV730 card with DCE-3 display
engine and on a evergreen card with DCE-4 display engine, in single-display
and dual-display configuration, with different video modes.

A similar patch is needed for amdgpu-kms to fix the same problem.

Limitations:

- Line buffer sizes in pixels are hard-coded on < DCE-4 to a value
  i just guessed to be high enough to work ok, lacking info on the true
  sizes atm.

Fixes: fdo#93147
Signed-off-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Michel Dänzer <michel.daenzer@amd.com>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>

(v1) Tested-by: Dave Witbrodt <dawitbro@sbcglobal.net>

(v2) Refine radeon_flip_work_func() for better efficiency:

     In radeon_flip_work_func, replace the busy waiting udelay(5)
     with event lock held by a more performance and energy efficient
     usleep_range() until at least predicted true start of hw vblank,
     with some slack for scheduler happiness. Release the event lock
     during waits to not delay other outputs in doing their stuff, as
     the waiting can last up to 200 usecs in some cases.

     Retested on DCE-3 and DCE-4 to verify it still works nicely.

(v2) Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
      5b5561b3
    • L
      drm/radeon: Retry DDC probing on DVI on failure if we got an HPD interrupt · cb5d4166
      由 Lyude 提交于 
      HPD signals on DVI ports can be fired off before the pins required for
DDC probing actually make contact, due to the pins for HPD making
contact first. This results in a HPD signal being asserted but DDC
probing failing, resulting in hotplugging occasionally failing.

This is somewhat rare on most cards (depending on what angle you plug
the DVI connector in), but on some cards it happens constantly. The
Radeon R5 on the machine used for testing this patch for instance, runs
into this issue just about every time I try to hotplug a DVI monitor and
as a result hotplugging almost never works.

Rescheduling the hotplug work for a second when we run into an HPD
signal with a failing DDC probe usually gives enough time for the rest
of the connector's pins to make contact, and fixes this issue.
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NLyude <cpaul@redhat.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
      cb5d4166
    • J
      drm/amdgpu: add spin lock to protect freed list in vm (v2) · 81d75a30
      由 jimqu 提交于 
      there is a protection fault about freed list when OCL test.
add a spin lock to protect it.

v2: drop changes in vm_fini
Signed-off-by: NJimQu <jim.qu@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
      81d75a30
    • C
      drm/amdgpu: partially revert "drm/amdgpu: fix VM_CONTEXT*_PAGE_TABLE_END_ADDR" v2 · 9c97b5ab
      由 Christian König 提交于 
      The gtt_end is already inclusive, we don't need to subtract one here.

v2 (chk): keep the fix for the VM code, cause here it really applies.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAnatoli Antonovitch <anatoli.antonovitch@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
      9c97b5ab
    • C
      drm/amdgpu: take a BO reference for the user fence · f3f17692
      由 Christian König 提交于 
      No need for a GEM reference here.
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
      f3f17692
    • C
      drm/amdgpu: take a BO reference in the display code · e9d951a8
      由 Christian König 提交于 
      No need for the GEM reference here.
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
      e9d951a8
    • C
      drm/amdgpu: set snooped flags only on system addresses v2 · 6d99905a
      由 Christian König 提交于 
      Not necessary for VRAM.

v2: no need to check if ttm is NULL.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
      6d99905a
  3. 03 12月, 2015 2 次提交
  5. 01 12月, 2015 3 次提交
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