Chris Wilson 7c34bb0398 drm/i915: Tighten atomicity of i915_active_acquire vs i915_active_release ... As we use a mutex to serialise the first acquire (as it may be a lengthy operation), but only an atomic decrement for the release, we have to be careful in case a second thread races and completes both acquire/release as the first finishes its acquire. Thread A Thread B i915_active_acquire i915_active_acquire atomic_read() == 0 atomic_read() == 0 mutex_lock() mutex_lock() atomic_read() == 0 ref->active(); atomic_inc() mutex_unlock() atomic_read() == 1 i915_active_release atomic_dec_and_test() -> 0 ref->retire() atomic_inc() -> 1 mutex_unlock() So thread A has acquired the ref->active_count but since the ref was still active at the time, it did not initialise it. By switching the check inside the mutex to an atomic increment only if already active, we close the race. Fixes: c9ad602fea ("drm/i915: Split i915_active.mutex into an irq-safe spinlock for the rbtree") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200126102346.1877661-3-chris@chris-wilson.co.uk (cherry picked from commit ac0e331a62) Signed-off-by: Jani Nikula <jani.nikula@intel.com>		2020-02-12 13:24:44 +02:00
..
amd	drm/amd/dm/mst: Ignore payload update failures	2020-02-04 23:30:39 -05:00
arc	DRM: ARC: PGU: add ARGB8888 format to supported format list	2019-12-16 13:53:05 +03:00
arm	Linux 5.5-rc7	2020-01-20 11:42:57 +10:00
armada
aspeed
ast	drm/vram-helper: Remove BO device from public interface	2020-01-07 11:53:19 +01:00
atmel-hlcdc	Revert "drm: atmel-hlcdc: enable sys_clk during initalization."	2020-01-06 19:54:27 +01:00
bochs	drm/bochs: Remove unneeded semicolon	2019-12-16 12:39:50 +01:00
bridge	Revert "drm/bridge: Patch atomic hooks to take a drm_bridge_state"	2020-01-08 00:34:28 +01:00
cirrus
etnaviv	Merge tag 'amd-drm-next-5.6-2020-01-09' of git://people.freedesktop.org/~agd5f/linux into drm-next	2020-01-13 16:49:02 +10:00
exynos	drm/exynos: Rename Exynos to lowercase	2020-01-21 09:09:42 +09:00
fsl-dcu
gma500	drm/gma500: remove set but not used variables 'hist_reg'	2020-01-08 10:07:58 +01:00
hisilicon	drm/vram-helper: Remove BO device from public interface	2020-01-07 11:53:19 +01:00
i2c
i810
i915	drm/i915: Tighten atomicity of i915_active_acquire vs i915_active_release	2020-02-12 13:24:44 +02:00
imx
ingenic	gpu/drm: ingenic: Add support for the JZ4770	2019-12-14 19:26:55 +01:00
lib
lima	Merge tag 'amd-drm-next-5.6-2020-01-09' of git://people.freedesktop.org/~agd5f/linux into drm-next	2020-01-13 16:49:02 +10:00
mcde	drm-misc-next for v5.6:	2020-01-03 11:43:44 +10:00
mediatek	Linux 5.5-rc7	2020-01-20 11:42:57 +10:00
meson	drm: meson: fix address type confusion	2020-01-08 13:51:56 +01:00
mga
mgag200	drm/mgag200: Add module parameter to pin all buffers at offset 0	2020-01-07 11:53:19 +01:00
msm	Merge tag 'drm-msm-next-2020-01-14' of https://gitlab.freedesktop.org/drm/msm into drm-next	2020-01-20 14:09:43 +10:00
mxsfb
nouveau	drm/nouveau/kms/gv100-: avoid sending a core update until the first modeset	2020-02-03 21:36:54 +10:00
omapdrm	drm/omapdrm: use BUG_ON macro for error debugging.	2020-01-08 18:35:36 +01:00
panel	drm/panel: simple: Add Satoz SAT050AT40H12R2 panel support	2020-01-09 20:27:06 +01:00
panfrost	drm/scheduler: rework entity creation	2019-12-18 16:09:12 -05:00
pl111
qxl
r128
radeon	radeon: completely remove lut leftovers	2020-01-30 17:15:43 -05:00
rcar-du	Revert "drm/bridge: Patch atomic hooks to take a drm_bridge_state"	2020-01-08 00:34:28 +01:00
rockchip	Linux 5.5-rc7	2020-01-20 11:42:57 +10:00
savage
scheduler	drm/amdgpu: fix doc by clarifying sched_list definition	2020-01-27 16:46:44 -05:00
selftests	Merge tag 'amd-drm-next-5.6-2020-01-10-dp-mst-dsc' of git://people.freedesktop.org/~agd5f/linux into drm-next	2020-01-13 17:14:34 +10:00
shmobile
sis
sti
stm	drm/stm: ltdc: move pinctrl to encoder mode set	2019-12-20 13:30:42 +01:00
sun4i	Linux 5.5-rc7	2020-01-20 11:42:57 +10:00
tdfx
tegra	drm/tegra: Fixes for v5.6-rc1	2020-02-07 12:22:30 +10:00
tilcdc	drm/tilcdc: Remove obsolete bundled tilcdc tfp410 driver	2019-12-16 10:45:43 +02:00
tiny
ttm	mm, drm/ttm: Fix vm page protection handling	2020-01-16 10:32:41 +01:00
tve200
udl	drm/udl: Make udl driver depend on CONFIG_USB	2020-01-09 15:02:48 +01:00
v3d	drm/scheduler: rework entity creation	2019-12-18 16:09:12 -05:00
vboxvideo
vc4	drm/vc4: dsi: Fix bridge chain handling	2020-01-08 09:09:48 +01:00
vgem
via
virtio	Linux 5.5-rc7	2020-01-20 11:42:57 +10:00
vkms
vmwgfx	drm/vmwgfx: Use VM_PFNMAP instead of VM_MIXEDMAP when possible	2020-01-15 14:34:49 +01:00
xen
zte	drm: zte: Provide ddc symlink in vga connector sysfs directory	2020-01-07 20:26:02 +01:00
drm_agpsupport.c
drm_atomic_helper.c	Revert "drm/bridge: Add a drm_bridge_state object"	2020-01-08 00:34:34 +01:00
drm_atomic_state_helper.c	drm: Add __drm_atomic_helper_crtc_state_reset() & co.	2019-12-18 16:47:34 +02:00
drm_atomic_uapi.c	drm/atomic: Spell CRTC consistently	2019-12-22 11:13:00 +01:00
drm_atomic.c	Revert "drm/bridge: Add a drm_bridge_state object"	2020-01-08 00:34:34 +01:00
drm_auth.c
drm_blend.c
drm_bridge.c	Revert "drm/bridge: Add a drm_bridge_state object"	2020-01-08 00:34:34 +01:00
drm_bufs.c
drm_cache.c
drm_client_modeset.c	drm/fbdev: Fallback to non tiled mode if all tiles not present	2019-12-29 23:55:23 -08:00
drm_client.c	drm/client: convert to drm device based logging	2019-12-19 15:52:44 +02:00
drm_color_mgmt.c
drm_connector.c
drm_context.c
drm_crtc_helper_internal.h
drm_crtc_helper.c
drm_crtc_internal.h
drm_crtc.c
drm_damage_helper.c
drm_debugfs_crc.c	drm: Set crc->opened to false before setting crc source to NULL.	2020-01-07 15:29:40 -05:00
drm_debugfs.c
drm_dma.c
drm_dp_aux_dev.c	drm/dp_mst: Add MST support to DP DPCD R/W functions	2020-01-09 18:07:46 -05:00
drm_dp_cec.c
drm_dp_dual_mode_helper.c
drm_dp_helper.c	drm: add dp helper to initialize remote aux channel.	2020-01-09 18:07:48 -05:00
drm_dp_mst_topology_internal.h
drm_dp_mst_topology.c	Linux 5.5-rc7	2020-01-20 11:42:57 +10:00
drm_drv.c	drm: remove duplicate check on parent and avoid BUG_ON	2019-12-17 17:26:08 +01:00
drm_dsc.c
drm_dumb_buffers.c
drm_edid_load.c
drm_edid.c	drm: Fix a couple of typos, punctation and whitespace issues	2019-12-22 11:09:46 +01:00
drm_encoder_slave.c
drm_encoder.c
drm_fb_cma_helper.c	drm/fb-cma-helpers: Fix include issue	2020-01-09 17:33:41 +01:00
drm_fb_helper.c	Linux 5.5-rc7	2020-01-20 11:42:57 +10:00
drm_file.c	i915 features for v5.6:	2019-12-27 15:25:04 +10:00
drm_flip_work.c
drm_format_helper.c
drm_fourcc.c
drm_framebuffer.c
drm_gem_cma_helper.c
drm_gem_framebuffer_helper.c	drm/gem-fb-helper: convert to drm device based logging	2019-12-19 15:55:10 +02:00
drm_gem_shmem_helper.c
drm_gem_ttm_helper.c
drm_gem_vram_helper.c	drm/vram-helper: Support struct drm_driver.gem_create_object	2020-01-07 11:53:19 +01:00
drm_gem.c	drm-misc-next for v5.6:	2019-12-17 13:57:54 +01:00
drm_hashtab.c
drm_hdcp.c
drm_internal.h
drm_ioc32.c
drm_ioctl.c
drm_irq.c
drm_kms_helper_common.c
drm_lease.c
drm_legacy_misc.c
drm_legacy.h
drm_lock.c	gpu/drm: clean up white space in drm_legacy_lock_master_cleanup()	2020-01-08 19:51:11 +01:00
drm_memory.c
drm_mipi_dbi.c	drm/mipi_dbi: Fix off-by-one bugs in mipi_dbi_blank()	2020-01-02 15:35:56 +01:00
drm_mipi_dsi.c
drm_mm.c
drm_mode_config.c
drm_mode_object.c
drm_modes.c	drm/modes: tag unused variables to avoid warnings	2020-01-09 17:17:28 +01:00
drm_modeset_helper.c
drm_modeset_lock.c
drm_of.c	drm: of: Add drm_of_lvds_get_dual_link_pixel_order	2019-12-18 02:40:16 +02:00
drm_panel_orientation_quirks.c
drm_panel.c	drm/drm_panel: Fix EXPORT of drm_panel_of_backlight() one more time	2019-12-17 20:39:33 +01:00
drm_pci.c
drm_plane_helper.c
drm_plane.c
drm_prime.c
drm_print.c
drm_probe_helper.c
drm_property.c
drm_rect.c
drm_scatter.c
drm_scdc_helper.c
drm_self_refresh_helper.c
drm_simple_kms_helper.c
drm_syncobj.c
drm_sysfs.c
drm_trace_points.c
drm_trace.h
drm_vblank.c
drm_vm.c
drm_vma_manager.c
drm_vram_helper_common.c
drm_writeback.c
Kconfig	drm/Kconfig: add missing 'depends on DRM' for DRM_DP_CEC	2020-01-09 10:16:35 +01:00
Makefile