linux/drivers/gpu/drm
John Harrison dbe4646d6e drm/i915: Fix for ringbuf space wait in LRC mode
The legacy and LRC code paths have an almost identical procedure for waiting for
space in the ring buffer. They both search for a request in the free list that
will advance the tail to a point where sufficient space is available. They then
wait for that request, retire it and recalculate the free space value.

Unfortunately, a bug in the LRC side meant that the resulting free space might
not be as large as expected and indeed, might not be sufficient. This is because
it was testing against the value of request->tail not request->postfix. Whereas,
when a request is retired, ringbuf->tail is updated to req->postfix not
req->tail.

Another significant difference between the two is that the LRC one did not trust
the wait for request to work! It redid the is there enough space available test
and would fail the call if insufficient. Whereas, the legacy version just said
'return 0' - it assumed the preceeding code works. This difference meant that
the LRC version still worked even with the bug - it just fell back to the
polling wait path.

For: VIZ-5115
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Thomas Daniel <thomas.daniel@intel.com>
Reviewed-by: Tomas Elf <tomas.elf@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-04-01 07:54:43 +02:00
..
amd drm/amdkfd: Fix SDMA queue init. in non-HWS mode 2015-03-16 23:36:58 +02:00
armada Merge tag 'topic/core-stuff-2014-12-19' of git://anongit.freedesktop.org/drm-intel into drm-next 2015-01-09 09:13:41 +10:00
ast drm/fb-helper: Propagate errors from initial config failure 2015-01-21 14:57:03 +01:00
atmel-hlcdc Linux 4.0-rc3 2015-03-09 19:58:30 +10:00
bochs drm/fb-helper: Propagate errors from initial config failure 2015-01-21 14:57:03 +01:00
bridge drm/bridge: dw-hdmi: Adapt to bridge API change 2015-01-28 10:01:30 +01:00
cirrus Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-02-16 15:48:00 -08:00
exynos drm/exynos: fix the initialization order in FIMD 2015-03-18 20:41:19 +09:00
gma500 drm/fb-helper: Propagate errors from initial config failure 2015-01-21 14:57:03 +01:00
i2c drm: Fix trivial typos in comments 2015-03-10 09:59:34 +01:00
i810
i915 drm/i915: Fix for ringbuf space wait in LRC mode 2015-04-01 07:54:43 +02:00
imx DRM: i.MX: parallel display: Support probe deferral for finding DRM panel 2015-02-23 17:19:25 +01:00
mga
mgag200 drm/fb-helper: Propagate errors from initial config failure 2015-01-21 14:57:03 +01:00
msm Linux 4.0-rc3 2015-03-09 19:58:30 +10:00
nouveau drm/nouveau/bios: fix i2c table parsing for dcb 4.1 2015-03-17 09:44:23 +10:00
omapdrm drm/fb-helper: Propagate errors from initial config failure 2015-01-21 14:57:03 +01:00
panel drm: panel/simple: add backlight dependency 2015-01-31 10:11:45 +10:00
qxl drm/fb-helper: Propagate errors from initial config failure 2015-01-21 14:57:03 +01:00
r128
radeon Merge tag 'drm-amdkfd-fixes-2015-03-19' of git://people.freedesktop.org/~gabbayo/linux into drm-fixes 2015-03-20 17:32:01 +10:00
rcar-du drm: rcar-du: Fix race condition in hardware plane allocator 2015-03-03 16:16:30 +02:00
rockchip Revert "drm/rockchip: Flip select/depends in Kconfig" 2015-03-03 21:11:34 +10:00
savage
shmobile drm: Kconfig: Let all DRM_GEM_CMA_HELPER related macros depend on HAVE_DMA_ATTRS 2015-02-03 11:12:37 +10:00
sis
sti drm: sti: HDMI add audio infoframe 2015-02-05 16:21:19 +01:00
tdfx
tegra Linux 4.0-rc3 2015-03-09 19:58:30 +10:00
tilcdc drm: Kconfig: Let all DRM_GEM_CMA_HELPER related macros depend on HAVE_DMA_ATTRS 2015-02-03 11:12:37 +10:00
ttm drm/ttm: device address space != CPU address space 2015-03-05 09:04:39 +10:00
udl drm/udl: properly set active_16 flag in udl_crtc_page_flip(). (v2) 2015-01-31 10:12:23 +10:00
via
vmwgfx drm/vmwgfx: Fix an issue with the device losing its irq line on module unload 2015-03-11 11:47:41 -07:00
ati_pcigart.c
drm_agpsupport.c
drm_atomic_helper.c drm/atomic-helper: Fix kerneldoc for prepare_planes 2015-03-10 09:59:31 +01:00
drm_atomic.c drm: Share plane pixel format check code between legacy and atomic 2015-03-10 09:59:35 +01:00
drm_auth.c
drm_bridge.c drm/bridge: make bridge registration independent of drm flow 2015-01-28 08:45:40 +01:00
drm_bufs.c
drm_cache.c drm/cache: Use wbinvd helpers 2014-12-16 08:56:55 +01:00
drm_context.c
drm_crtc_helper.c drm: add support for tiled/compressed/etc modifier in addfb2 2015-02-13 23:28:12 +01:00
drm_crtc_internal.h drm/atomic: Hide drm.ko internal interfaces 2015-01-05 13:55:30 +01:00
drm_crtc.c drm: Fixup racy refcounting in plane_force_disable 2015-03-24 12:04:35 +10:00
drm_debugfs.c
drm_dma.c
drm_dp_helper.c drm/dp: add drm_dp_link_power_down() helper 2015-02-01 15:06:42 -05:00
drm_dp_mst_topology.c drm/mst: fix recursive sleep warning on qlock 2015-03-10 13:44:31 +10:00
drm_drv.c drm: add atomic properties 2015-01-05 13:54:38 +01:00
drm_edid_load.c
drm_edid.c Merge tag 'topic/core-stuff-2014-12-10' of git://anongit.freedesktop.org/drm-intel into drm-next 2014-12-11 10:12:57 +10:00
drm_encoder_slave.c
drm_fb_cma_helper.c
drm_fb_helper.c Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-02-16 15:48:00 -08:00
drm_flip_work.c
drm_fops.c drm: Make drm_read() more robust against multithreaded races 2015-01-21 14:57:03 +01:00
drm_gem_cma_helper.c
drm_gem.c
drm_global.c
drm_hashtab.c
drm_info.c drm/info: Remove unused code 2014-12-16 18:44:34 +01:00
drm_internal.h drm/info: Remove unused code 2014-12-16 18:44:34 +01:00
drm_ioc32.c
drm_ioctl.c drm: add support for tiled/compressed/etc modifier in addfb2 2015-02-13 23:28:12 +01:00
drm_irq.c Merge tag 'drm-intel-next-2015-02-27' of git://anongit.freedesktop.org/drm-intel into drm-next 2015-03-09 19:41:15 +10:00
drm_legacy.h
drm_lock.c
drm_memory.c
drm_mipi_dsi.c drm/mipi-dsi: Avoid potential NULL pointer dereference 2015-01-28 08:45:37 +01:00
drm_mm.c [PATCH] drm/mm: Fix support 4 GiB and larger ranges 2015-03-16 06:28:50 +10:00
drm_modes.c drm: Fix trivial typos in comments 2015-03-10 09:59:34 +01:00
drm_modeset_lock.c
drm_of.c
drm_panel.c
drm_pci.c
drm_plane_helper.c drm: Check in setcrtc if the primary plane supports the fb pixel format 2015-03-10 09:59:36 +01:00
drm_platform.c
drm_prime.c
drm_probe_helper.c drm/probe-helper: clamp unknown connector status in the poll work 2015-01-22 06:11:39 +01:00
drm_rect.c
drm_scatter.c
drm_sysfs.c drm: Lighten sysfs connector 'status' 2015-03-10 09:59:36 +01:00
drm_trace_points.c
drm_trace.h
drm_vm.c
drm_vma_manager.c mm: remove rest usage of VM_NONLINEAR and pte_file() 2015-02-10 14:30:31 -08:00
Kconfig drm: Kconfig: Let all DRM_GEM_CMA_HELPER related macros depend on HAVE_DMA_ATTRS 2015-02-03 11:12:37 +10:00
Makefile drm/bridge: make bridge registration independent of drm flow 2015-01-28 08:45:40 +01:00