Back in April, I posted an RFC patch set to help mitigate a common issue
where a timer gets armed just before it is freed, and when the timer
goes off, it crashes in the timer code without any evidence of who the
culprit was. I got side tracked and never finished up on that patch set.
Since this type of crash is still our #1 crash we are seeing in the field,
it has become a priority again to finish it.
This is v3 of that patch set. Thomas Gleixner posted an untested version
that makes timer->function NULL as the flag that it is shutdown. I took that
code, tested it (fixed it up), added more comments, and changed the
name to timer_shutdown_sync(). I also converted it to use WARN_ON_ONCE()
instead of just WARN_ON() as Linus asked for.
I then created a trivial coccinelle script to find where del_timer*()
is called before being freed, and converted them all to timer_shutdown*()
(There was a couple that still used del_timer() instead of del_timer_sync()).
I also updated DEBUG_OBJECTS_TIMERS to check from where the timer is ever
armed, to calling of timer_shutdown_sync(), and it will trigger if a timer
is freed in between. The current way is to only check if the timer is armed,
but that means it only triggers if the race condition is hit, and with
experience, it's not run on enough machines to catch all of them. By triggering
it from the time the timer is armed to the time it is shutdown, it catches
all potential cases even if the race condition is not hit.
I went though the result of the cocinelle script, and updated the locations.
Some locations were caught by DEBUG_OBJECTS_TIMERS as the coccinelle script
only checked for timers being freed in the same function as the del_timer*().
Ideally, I would have the first patch go into this rc cycle, which is mostly
non functional as it will allow the other patches to come in via the respective
subsystems in the next merge window.
Changes since v2: https://lore.kernel.org/all/20221027150525.753064657@goodmis.org/
- Talking with Thomas Gleixner, he wanted a better name space and to remove
the "del_" portion of the API.
- Since there's now a shutdown interface that does not synchronize, to keep
it closer to del_timer() and del_timer_sync(), the API is now:
timer_shutdown() - same as del_timer() but deactivates the timer.
timer_shutdown_sync() - same as del_timer_sync() but deactivates the timer.
- Added a few more locations that got converted.
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace/timers
Head SHA1: 25106f0bb7968b3e8c746a7853f44b51840746c3
Steven Rostedt (Google) (33):
timers: Add timer_shutdown_sync() and timer_shutdown() to be called before freeing timers
timers: s390/cmm: Use timer_shutdown_sync() before freeing timer
timers: sh: Use timer_shutdown_sync() before freeing timer
timers: block: Use timer_shutdown_sync() before freeing timer
timers: ACPI: Use timer_shutdown_sync() before freeing timer
timers: atm: Use timer_shutdown_sync() before freeing timer
timers: PM: Use timer_shutdown_sync()
timers: Bluetooth: Use timer_shutdown_sync() before freeing timer
timers: hangcheck: Use timer_shutdown_sync() before freeing timer
timers: ipmi: Use timer_shutdown_sync() before freeing timer
random: use timer_shutdown_sync() before freeing timer
timers: dma-buf: Use timer_shutdown_sync() before freeing timer
timers: drm: Use timer_shutdown_sync() before freeing timer
timers: HID: Use timer_shutdown_sync() before freeing timer
timers: Input: Use timer_shutdown_sync() before freeing timer
timers: mISDN: Use timer_shutdown_sync() before freeing timer
timers: leds: Use timer_shutdown_sync() before freeing timer
timers: media: Use timer_shutdown_sync() before freeing timer
timers: net: Use timer_shutdown_sync() before freeing timer
timers: usb: Use timer_shutdown_sync() before freeing timer
timers: cgroup: Use timer_shutdown_sync() before freeing timer
timers: workqueue: Use timer_shutdown_sync() before freeing timer
timers: nfc: pn533: Use timer_shutdown_sync() before freeing timer
timers: pcmcia: Use timer_shutdown_sync() before freeing timer
timers: scsi: Use timer_shutdown_sync() and timer_shutdown() before freeing timer
timers: tty: Use timer_shutdown_sync() before freeing timer
timers: ext4: Use timer_shutdown_sync() before freeing timer
timers: fs/nilfs2: Use timer_shutdown_sync() before freeing timer
timers: ALSA: Use timer_shutdown_sync() before freeing timer
timers: jbd2: Use timer_shutdown() before freeing timer
timers: sched/psi: Use timer_shutdown_sync() before freeing timer
timers: x86/mce: Use __init_timer() for resetting timers
timers: Expand DEBUG_OBJECTS_TIMER to check if it ever was used
----
.../RCU/Design/Requirements/Requirements.rst | 2 +-
Documentation/core-api/local_ops.rst | 2 +-
Documentation/kernel-hacking/locking.rst | 5 +
arch/s390/mm/cmm.c | 4 +-
arch/sh/drivers/push-switch.c | 2 +-
arch/x86/kernel/cpu/mce/core.c | 14 ++-
block/blk-iocost.c | 2 +-
block/blk-iolatency.c | 2 +-
block/blk-stat.c | 2 +-
block/blk-throttle.c | 2 +-
block/kyber-iosched.c | 2 +-
drivers/acpi/apei/ghes.c | 2 +-
drivers/atm/idt77105.c | 4 +-
drivers/atm/idt77252.c | 4 +-
drivers/atm/iphase.c | 2 +-
drivers/base/power/wakeup.c | 7 +-
drivers/block/drbd/drbd_main.c | 2 +-
drivers/block/loop.c | 2 +-
drivers/block/sunvdc.c | 2 +-
drivers/bluetooth/hci_bcsp.c | 2 +-
drivers/bluetooth/hci_h5.c | 2 +-
drivers/bluetooth/hci_qca.c | 4 +-
drivers/char/hangcheck-timer.c | 4 +-
drivers/char/ipmi/ipmi_msghandler.c | 2 +-
drivers/char/ipmi/ipmi_ssif.c | 4 +-
drivers/char/random.c | 2 +-
drivers/dma-buf/st-dma-fence.c | 2 +-
drivers/gpu/drm/gud/gud_pipe.c | 2 +-
drivers/gpu/drm/i915/i915_sw_fence.c | 2 +-
drivers/hid/hid-wiimote-core.c | 2 +-
drivers/input/keyboard/locomokbd.c | 2 +-
drivers/input/keyboard/omap-keypad.c | 2 +-
drivers/input/mouse/alps.c | 2 +-
drivers/input/serio/hil_mlc.c | 2 +-
drivers/input/serio/hp_sdc.c | 2 +-
drivers/isdn/hardware/mISDN/hfcmulti.c | 6 +-
drivers/isdn/mISDN/l1oip_core.c | 4 +-
drivers/isdn/mISDN/timerdev.c | 4 +-
drivers/leds/trigger/ledtrig-activity.c | 2 +-
drivers/leds/trigger/ledtrig-heartbeat.c | 2 +-
drivers/leds/trigger/ledtrig-pattern.c | 2 +-
drivers/leds/trigger/ledtrig-transient.c | 2 +-
drivers/media/pci/ivtv/ivtv-driver.c | 2 +-
drivers/media/usb/pvrusb2/pvrusb2-hdw.c | 18 ++--
drivers/media/usb/s2255/s2255drv.c | 4 +-
drivers/net/ethernet/intel/i40e/i40e_main.c | 6 +-
drivers/net/ethernet/marvell/sky2.c | 2 +-
drivers/net/ethernet/sun/sunvnet.c | 2 +-
drivers/net/usb/sierra_net.c | 2 +-
drivers/net/wireless/intel/iwlwifi/iwl-dbg-tlv.c | 2 +-
drivers/net/wireless/intersil/hostap/hostap_ap.c | 2 +-
drivers/net/wireless/marvell/mwifiex/main.c | 2 +-
drivers/net/wireless/microchip/wilc1000/hif.c | 8 +-
drivers/nfc/pn533/pn533.c | 2 +-
drivers/nfc/pn533/uart.c | 2 +-
drivers/pcmcia/bcm63xx_pcmcia.c | 2 +-
drivers/pcmcia/electra_cf.c | 2 +-
drivers/pcmcia/omap_cf.c | 2 +-
drivers/pcmcia/pd6729.c | 4 +-
drivers/pcmcia/yenta_socket.c | 4 +-
drivers/scsi/qla2xxx/qla_edif.c | 4 +-
drivers/scsi/scsi_lib.c | 1 +
drivers/staging/media/atomisp/i2c/atomisp-lm3554.c | 2 +-
drivers/tty/n_gsm.c | 2 +-
drivers/tty/sysrq.c | 2 +-
drivers/usb/gadget/udc/m66592-udc.c | 2 +-
drivers/usb/serial/garmin_gps.c | 2 +-
drivers/usb/serial/mos7840.c | 2 +-
fs/ext4/super.c | 2 +-
fs/jbd2/journal.c | 2 +
fs/nilfs2/segment.c | 2 +-
include/linux/timer.h | 100 +++++++++++++++++--
include/linux/workqueue.h | 4 +-
kernel/cgroup/cgroup.c | 2 +-
kernel/sched/psi.c | 1 +
kernel/time/timer.c | 106 ++++++++++++++-------
kernel/workqueue.c | 4 +-
net/802/garp.c | 2 +-
net/802/mrp.c | 2 +-
net/bridge/br_multicast.c | 6 +-
net/bridge/br_multicast_eht.c | 4 +-
net/core/gen_estimator.c | 2 +-
net/core/neighbour.c | 2 +
net/ipv4/inet_connection_sock.c | 2 +-
net/ipv4/inet_timewait_sock.c | 3 +-
net/ipv4/ipmr.c | 2 +-
net/ipv6/ip6mr.c | 2 +-
net/mac80211/mesh_pathtbl.c | 2 +-
net/netfilter/ipset/ip_set_list_set.c | 2 +-
net/netfilter/ipvs/ip_vs_lblc.c | 2 +-
net/netfilter/ipvs/ip_vs_lblcr.c | 2 +-
net/netfilter/xt_LED.c | 2 +-
net/rxrpc/conn_object.c | 2 +-
net/sched/cls_flow.c | 2 +-
net/sunrpc/svc.c | 2 +-
net/sunrpc/xprt.c | 2 +-
net/tipc/discover.c | 2 +-
net/tipc/monitor.c | 2 +-
sound/i2c/other/ak4117.c | 2 +-
sound/synth/emux/emux.c | 2 +-
100 files changed, 310 insertions(+), 175 deletions(-)
From: Rob Clark <robdclark(a)chromium.org>
The workaround was initially necessary due to dma_resv having only a
single exclusive fence slot, yet whe don't necessarily know what order
the gpu scheduler will schedule jobs. Unfortunately this workaround
also has the result of forcing implicit sync, even when userspace does
not want it.
However, since commit 047a1b877ed4 ("dma-buf & drm/amdgpu: remove
dma_resv workaround") the workaround is no longer needed. So remove
it. This effectively reverts commit f1b3f696a084 ("drm/msm: Don't
break exclusive fence ordering")
Signed-off-by: Rob Clark <robdclark(a)chromium.org>
---
drivers/gpu/drm/msm/msm_gem_submit.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 5599d93ec0d2..cc48f73adadf 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -334,8 +334,7 @@ static int submit_fence_sync(struct msm_gem_submit *submit, bool no_implicit)
if (ret)
return ret;
- /* exclusive fences must be ordered */
- if (no_implicit && !write)
+ if (no_implicit)
continue;
ret = drm_sched_job_add_implicit_dependencies(&submit->base,
--
2.38.1
The use of kmap() is being deprecated in favor of kmap_local_page().
There are two main problems with kmap(): (1) It comes with an overhead as
the mapping space is restricted and protected by a global lock for
synchronization and (2) it also requires global TLB invalidation when the
kmap’s pool wraps and it might block when the mapping space is fully
utilized until a slot becomes available.
With kmap_local_page() the mappings are per thread, CPU local, can take
page faults, and can be called from any context (including interrupts).
It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore,
the tasks can be preempted and, when they are scheduled to run again, the
kernel virtual addresses are restored and still valid.
Therefore, replace kmap() with kmap_local_page() in radeon_ttm_gtt_read().
Cc: "Venkataramanan, Anirudh" <anirudh.venkataramanan(a)intel.com>
Suggested-by: Ira Weiny <ira.weiny(a)intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco(a)gmail.com>
---
drivers/gpu/drm/radeon/radeon_ttm.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index d33fec488713..bdb4c0e0736b 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -869,11 +869,11 @@ static ssize_t radeon_ttm_gtt_read(struct file *f, char __user *buf,
page = rdev->gart.pages[p];
if (page) {
- ptr = kmap(page);
+ ptr = kmap_local_page(page);
ptr += off;
r = copy_to_user(buf, ptr, cur_size);
- kunmap(rdev->gart.pages[p]);
+ kunmap_local(ptr);
} else
r = clear_user(buf, cur_size);
--
2.37.3
Hello,
This series moves all drivers to a dynamic dma-buf locking specification.
From now on all dma-buf importers are made responsible for holding
dma-buf's reservation lock around all operations performed over dma-bufs
in accordance to the locking specification. This allows us to utilize
reservation lock more broadly around kernel without fearing of a potential
deadlocks.
This patchset passes all i915 selftests. It was also tested using VirtIO,
Panfrost, Lima, Tegra, udmabuf, AMDGPU and Nouveau drivers. I tested cases
of display+GPU, display+V4L and GPU+V4L dma-buf sharing (where appropriate),
which covers majority of kernel drivers since rest of the drivers share
same or similar code paths.
Changelog:
v6: - Added r-b from Michael Ruhl to the i915 patch.
- Added acks from Sumit Semwal and updated commit message of the
"Move dma_buf_vmap() to dynamic locking specification" patch like
was suggested by Sumit.
- Added "!dmabuf" check to dma_buf_vmap_unlocked() to match the locked
variant of the function, for consistency.
v5: - Added acks and r-bs that were given to v4.
- Changed i915 preparation patch like was suggested by Michael Ruhl.
The scope of reservation locking is smaller now.
v4: - Added dma_buf_mmap() to the "locking convention" documentation,
which was missed by accident in v3.
- Added acks from Christian König, Tomasz Figa and Hans Verkuil that
they gave to couple v3 patches.
- Dropped the "_unlocked" postfix from function names that don't have
the locked variant, as was requested by Christian König.
- Factored out the per-driver preparations into separate patches
to ease reviewing of the changes, which is now doable without the
global dma-buf functions renaming.
- Factored out the dynamic locking convention enforcements into separate
patches which add the final dma_resv_assert_held(dmabuf->resv) to the
dma-buf API functions.
v3: - Factored out dma_buf_mmap_unlocked() and attachment functions
into aseparate patches, like was suggested by Christian König.
- Corrected and factored out dma-buf locking documentation into
a separate patch, like was suggested by Christian König.
- Intel driver dropped the reservation locking fews days ago from
its BO-release code path, but we need that locking for the imported
GEMs because in the end that code path unmaps the imported GEM.
So I added back the locking needed by the imported GEMs, updating
the "dma-buf attachment locking specification" patch appropriately.
- Tested Nouveau+Intel dma-buf import/export combo.
- Tested udmabuf import to i915/Nouveau/AMDGPU.
- Fixed few places in Etnaviv, Panfrost and Lima drivers that I missed
to switch to locked dma-buf vmapping in the drm/gem: Take reservation
lock for vmap/vunmap operations" patch. In a result invalidated the
Christian's r-b that he gave to v2.
- Added locked dma-buf vmap/vunmap functions that are needed for fixing
vmappping of Etnaviv, Panfrost and Lima drivers mentioned above.
I actually had this change stashed for the drm-shmem shrinker patchset,
but then realized that it's already needed by the dma-buf patches.
Also improved my tests to better cover these code paths.
v2: - Changed locking specification to avoid problems with a cross-driver
ww locking, like was suggested by Christian König. Now the attach/detach
callbacks are invoked without the held lock and exporter should take the
lock.
- Added "locking convention" documentation that explains which dma-buf
functions and callbacks are locked/unlocked for importers and exporters,
which was requested by Christian König.
- Added ack from Tomasz Figa to the V4L patches that he gave to v1.
Dmitry Osipenko (21):
dma-buf: Add unlocked variant of vmapping functions
dma-buf: Add unlocked variant of attachment-mapping functions
drm/gem: Take reservation lock for vmap/vunmap operations
drm/prime: Prepare to dynamic dma-buf locking specification
drm/armada: Prepare to dynamic dma-buf locking specification
drm/i915: Prepare to dynamic dma-buf locking specification
drm/omapdrm: Prepare to dynamic dma-buf locking specification
drm/tegra: Prepare to dynamic dma-buf locking specification
drm/etnaviv: Prepare to dynamic dma-buf locking specification
RDMA/umem: Prepare to dynamic dma-buf locking specification
misc: fastrpc: Prepare to dynamic dma-buf locking specification
xen/gntdev: Prepare to dynamic dma-buf locking specification
media: videobuf2: Prepare to dynamic dma-buf locking specification
media: tegra-vde: Prepare to dynamic dma-buf locking specification
dma-buf: Move dma_buf_vmap() to dynamic locking specification
dma-buf: Move dma_buf_attach() to dynamic locking specification
dma-buf: Move dma_buf_map_attachment() to dynamic locking
specification
dma-buf: Move dma_buf_mmap() to dynamic locking specification
dma-buf: Document dynamic locking convention
media: videobuf2: Stop using internal dma-buf lock
dma-buf: Remove obsoleted internal lock
Documentation/driver-api/dma-buf.rst | 6 +
drivers/dma-buf/dma-buf.c | 214 +++++++++++++++---
drivers/gpu/drm/armada/armada_gem.c | 8 +-
drivers/gpu/drm/drm_client.c | 4 +-
drivers/gpu/drm/drm_gem.c | 24 ++
drivers/gpu/drm/drm_gem_dma_helper.c | 6 +-
drivers/gpu/drm/drm_gem_framebuffer_helper.c | 6 +-
drivers/gpu/drm/drm_gem_ttm_helper.c | 9 +-
drivers/gpu/drm/drm_prime.c | 6 +-
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_object.c | 14 ++
.../drm/i915/gem/selftests/i915_gem_dmabuf.c | 16 +-
drivers/gpu/drm/lima/lima_sched.c | 4 +-
drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 4 +-
drivers/gpu/drm/panfrost/panfrost_dump.c | 4 +-
drivers/gpu/drm/panfrost/panfrost_perfcnt.c | 6 +-
drivers/gpu/drm/qxl/qxl_object.c | 17 +-
drivers/gpu/drm/qxl/qxl_prime.c | 4 +-
drivers/gpu/drm/tegra/gem.c | 17 +-
drivers/infiniband/core/umem_dmabuf.c | 7 +-
.../common/videobuf2/videobuf2-dma-contig.c | 22 +-
.../media/common/videobuf2/videobuf2-dma-sg.c | 19 +-
.../common/videobuf2/videobuf2-vmalloc.c | 17 +-
.../platform/nvidia/tegra-vde/dmabuf-cache.c | 6 +-
drivers/misc/fastrpc.c | 6 +-
drivers/xen/gntdev-dmabuf.c | 8 +-
include/drm/drm_gem.h | 3 +
include/linux/dma-buf.h | 17 +-
29 files changed, 323 insertions(+), 155 deletions(-)
--
2.37.3
From: Liviu Dudau <liviu.dudau(a)arm.com>
[ Upstream commit eaa225b6b52233d45457fd33730e1528c604d92d ]
Komeda driver relies on the generic DRM atomic helper functions to handle
commits. It only implements an atomic_commit_tail hook for the
mode_config_helper_funcs and even that one is pretty close to the generic
implementation with the exception of additional dma_fence signalling.
What the generic helper framework doesn't do is waiting for the actual
hardware to signal that the commit parameters have been written into the
appropriate registers. As we signal CRTC events only on the irq handlers,
we need to flush the configuration and wait for the hardware to respond.
Add the Komeda specific implementation for atomic_commit_hw_done() that
flushes and waits for flip done before calling drm_atomic_helper_commit_hw_done().
The fix was prompted by a patch from Carsten Haitzler where he was trying to
solve the same issue but in a different way that I think can lead to wrong
event signaling to userspace.
Reported-by: Carsten Haitzler <carsten.haitzler(a)arm.com>
Tested-by: Carsten Haitzler <carsten.haitzler(a)arm.com>
Reviewed-by: Carsten Haitzler <carsten.haitzler(a)arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau(a)arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220722122139.288486-1-liviu…
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
.../gpu/drm/arm/display/komeda/komeda_crtc.c | 4 ++--
.../gpu/drm/arm/display/komeda/komeda_kms.c | 21 ++++++++++++++++++-
.../gpu/drm/arm/display/komeda/komeda_kms.h | 2 ++
3 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index 59172acb9738..292f533d8cf0 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -235,7 +235,7 @@ void komeda_crtc_handle_event(struct komeda_crtc *kcrtc,
crtc->state->event = NULL;
drm_crtc_send_vblank_event(crtc, event);
} else {
- DRM_WARN("CRTC[%d]: FLIP happen but no pending commit.\n",
+ DRM_WARN("CRTC[%d]: FLIP happened but no pending commit.\n",
drm_crtc_index(&kcrtc->base));
}
spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
@@ -286,7 +286,7 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc,
komeda_crtc_do_flush(crtc, old);
}
-static void
+void
komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc,
struct completion *input_flip_done)
{
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
index 93b7f09b96ca..327051bba5b6 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
@@ -69,6 +69,25 @@ static const struct drm_driver komeda_kms_driver = {
.minor = 1,
};
+static void komeda_kms_atomic_commit_hw_done(struct drm_atomic_state *state)
+{
+ struct drm_device *dev = state->dev;
+ struct komeda_kms_dev *kms = to_kdev(dev);
+ int i;
+
+ for (i = 0; i < kms->n_crtcs; i++) {
+ struct komeda_crtc *kcrtc = &kms->crtcs[i];
+
+ if (kcrtc->base.state->active) {
+ struct completion *flip_done = NULL;
+ if (kcrtc->base.state->event)
+ flip_done = kcrtc->base.state->event->base.completion;
+ komeda_crtc_flush_and_wait_for_flip_done(kcrtc, flip_done);
+ }
+ }
+ drm_atomic_helper_commit_hw_done(state);
+}
+
static void komeda_kms_commit_tail(struct drm_atomic_state *old_state)
{
struct drm_device *dev = old_state->dev;
@@ -81,7 +100,7 @@ static void komeda_kms_commit_tail(struct drm_atomic_state *old_state)
drm_atomic_helper_commit_modeset_enables(dev, old_state);
- drm_atomic_helper_commit_hw_done(old_state);
+ komeda_kms_atomic_commit_hw_done(old_state);
drm_atomic_helper_wait_for_flip_done(dev, old_state);
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
index 456f3c435719..bf6e8fba5061 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
@@ -182,6 +182,8 @@ void komeda_kms_cleanup_private_objs(struct komeda_kms_dev *kms);
void komeda_crtc_handle_event(struct komeda_crtc *kcrtc,
struct komeda_events *evts);
+void komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc,
+ struct completion *input_flip_done);
struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev *mdev);
void komeda_kms_detach(struct komeda_kms_dev *kms);
--
2.35.1
From: Liviu Dudau <liviu.dudau(a)arm.com>
[ Upstream commit eaa225b6b52233d45457fd33730e1528c604d92d ]
Komeda driver relies on the generic DRM atomic helper functions to handle
commits. It only implements an atomic_commit_tail hook for the
mode_config_helper_funcs and even that one is pretty close to the generic
implementation with the exception of additional dma_fence signalling.
What the generic helper framework doesn't do is waiting for the actual
hardware to signal that the commit parameters have been written into the
appropriate registers. As we signal CRTC events only on the irq handlers,
we need to flush the configuration and wait for the hardware to respond.
Add the Komeda specific implementation for atomic_commit_hw_done() that
flushes and waits for flip done before calling drm_atomic_helper_commit_hw_done().
The fix was prompted by a patch from Carsten Haitzler where he was trying to
solve the same issue but in a different way that I think can lead to wrong
event signaling to userspace.
Reported-by: Carsten Haitzler <carsten.haitzler(a)arm.com>
Tested-by: Carsten Haitzler <carsten.haitzler(a)arm.com>
Reviewed-by: Carsten Haitzler <carsten.haitzler(a)arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau(a)arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220722122139.288486-1-liviu…
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
.../gpu/drm/arm/display/komeda/komeda_crtc.c | 4 ++--
.../gpu/drm/arm/display/komeda/komeda_kms.c | 21 ++++++++++++++++++-
.../gpu/drm/arm/display/komeda/komeda_kms.h | 2 ++
3 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index 59172acb9738..292f533d8cf0 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -235,7 +235,7 @@ void komeda_crtc_handle_event(struct komeda_crtc *kcrtc,
crtc->state->event = NULL;
drm_crtc_send_vblank_event(crtc, event);
} else {
- DRM_WARN("CRTC[%d]: FLIP happen but no pending commit.\n",
+ DRM_WARN("CRTC[%d]: FLIP happened but no pending commit.\n",
drm_crtc_index(&kcrtc->base));
}
spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
@@ -286,7 +286,7 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc,
komeda_crtc_do_flush(crtc, old);
}
-static void
+void
komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc,
struct completion *input_flip_done)
{
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
index 93b7f09b96ca..327051bba5b6 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
@@ -69,6 +69,25 @@ static const struct drm_driver komeda_kms_driver = {
.minor = 1,
};
+static void komeda_kms_atomic_commit_hw_done(struct drm_atomic_state *state)
+{
+ struct drm_device *dev = state->dev;
+ struct komeda_kms_dev *kms = to_kdev(dev);
+ int i;
+
+ for (i = 0; i < kms->n_crtcs; i++) {
+ struct komeda_crtc *kcrtc = &kms->crtcs[i];
+
+ if (kcrtc->base.state->active) {
+ struct completion *flip_done = NULL;
+ if (kcrtc->base.state->event)
+ flip_done = kcrtc->base.state->event->base.completion;
+ komeda_crtc_flush_and_wait_for_flip_done(kcrtc, flip_done);
+ }
+ }
+ drm_atomic_helper_commit_hw_done(state);
+}
+
static void komeda_kms_commit_tail(struct drm_atomic_state *old_state)
{
struct drm_device *dev = old_state->dev;
@@ -81,7 +100,7 @@ static void komeda_kms_commit_tail(struct drm_atomic_state *old_state)
drm_atomic_helper_commit_modeset_enables(dev, old_state);
- drm_atomic_helper_commit_hw_done(old_state);
+ komeda_kms_atomic_commit_hw_done(old_state);
drm_atomic_helper_wait_for_flip_done(dev, old_state);
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
index 456f3c435719..bf6e8fba5061 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
@@ -182,6 +182,8 @@ void komeda_kms_cleanup_private_objs(struct komeda_kms_dev *kms);
void komeda_crtc_handle_event(struct komeda_crtc *kcrtc,
struct komeda_events *evts);
+void komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc,
+ struct completion *input_flip_done);
struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev *mdev);
void komeda_kms_detach(struct komeda_kms_dev *kms);
--
2.35.1
From: Liviu Dudau <liviu.dudau(a)arm.com>
[ Upstream commit eaa225b6b52233d45457fd33730e1528c604d92d ]
Komeda driver relies on the generic DRM atomic helper functions to handle
commits. It only implements an atomic_commit_tail hook for the
mode_config_helper_funcs and even that one is pretty close to the generic
implementation with the exception of additional dma_fence signalling.
What the generic helper framework doesn't do is waiting for the actual
hardware to signal that the commit parameters have been written into the
appropriate registers. As we signal CRTC events only on the irq handlers,
we need to flush the configuration and wait for the hardware to respond.
Add the Komeda specific implementation for atomic_commit_hw_done() that
flushes and waits for flip done before calling drm_atomic_helper_commit_hw_done().
The fix was prompted by a patch from Carsten Haitzler where he was trying to
solve the same issue but in a different way that I think can lead to wrong
event signaling to userspace.
Reported-by: Carsten Haitzler <carsten.haitzler(a)arm.com>
Tested-by: Carsten Haitzler <carsten.haitzler(a)arm.com>
Reviewed-by: Carsten Haitzler <carsten.haitzler(a)arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau(a)arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220722122139.288486-1-liviu…
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
.../gpu/drm/arm/display/komeda/komeda_crtc.c | 4 ++--
.../gpu/drm/arm/display/komeda/komeda_kms.c | 21 ++++++++++++++++++-
.../gpu/drm/arm/display/komeda/komeda_kms.h | 2 ++
3 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
index 59172acb9738..292f533d8cf0 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_crtc.c
@@ -235,7 +235,7 @@ void komeda_crtc_handle_event(struct komeda_crtc *kcrtc,
crtc->state->event = NULL;
drm_crtc_send_vblank_event(crtc, event);
} else {
- DRM_WARN("CRTC[%d]: FLIP happen but no pending commit.\n",
+ DRM_WARN("CRTC[%d]: FLIP happened but no pending commit.\n",
drm_crtc_index(&kcrtc->base));
}
spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
@@ -286,7 +286,7 @@ komeda_crtc_atomic_enable(struct drm_crtc *crtc,
komeda_crtc_do_flush(crtc, old);
}
-static void
+void
komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc,
struct completion *input_flip_done)
{
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
index 93b7f09b96ca..327051bba5b6 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
@@ -69,6 +69,25 @@ static const struct drm_driver komeda_kms_driver = {
.minor = 1,
};
+static void komeda_kms_atomic_commit_hw_done(struct drm_atomic_state *state)
+{
+ struct drm_device *dev = state->dev;
+ struct komeda_kms_dev *kms = to_kdev(dev);
+ int i;
+
+ for (i = 0; i < kms->n_crtcs; i++) {
+ struct komeda_crtc *kcrtc = &kms->crtcs[i];
+
+ if (kcrtc->base.state->active) {
+ struct completion *flip_done = NULL;
+ if (kcrtc->base.state->event)
+ flip_done = kcrtc->base.state->event->base.completion;
+ komeda_crtc_flush_and_wait_for_flip_done(kcrtc, flip_done);
+ }
+ }
+ drm_atomic_helper_commit_hw_done(state);
+}
+
static void komeda_kms_commit_tail(struct drm_atomic_state *old_state)
{
struct drm_device *dev = old_state->dev;
@@ -81,7 +100,7 @@ static void komeda_kms_commit_tail(struct drm_atomic_state *old_state)
drm_atomic_helper_commit_modeset_enables(dev, old_state);
- drm_atomic_helper_commit_hw_done(old_state);
+ komeda_kms_atomic_commit_hw_done(old_state);
drm_atomic_helper_wait_for_flip_done(dev, old_state);
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
index 7889e380ab23..7339339ef6b8 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
@@ -183,6 +183,8 @@ void komeda_kms_cleanup_private_objs(struct komeda_kms_dev *kms);
void komeda_crtc_handle_event(struct komeda_crtc *kcrtc,
struct komeda_events *evts);
+void komeda_crtc_flush_and_wait_for_flip_done(struct komeda_crtc *kcrtc,
+ struct completion *input_flip_done);
struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev *mdev);
void komeda_kms_detach(struct komeda_kms_dev *kms);
--
2.35.1