diff mbox series

[v2] ath10k: skip ath10k_halt during suspend for driver state RESTARTING

Message ID 20220426221859.v2.1.I650b809482e1af8d0156ed88b5dc2677a0711d46@changeid
State Superseded
Headers show
Series [v2] ath10k: skip ath10k_halt during suspend for driver state RESTARTING | expand

Commit Message

Abhishek Kumar April 26, 2022, 10:19 p.m. UTC 
Double free crash is observed when FW recovery(caused by wmi
timeout/crash) is followed by immediate suspend event. The FW recovery
is triggered by ath10k_core_restart() which calls driver clean up via
ath10k_halt(). When the suspend event occurs between the FW recovery,
the restart worker thread is put into frozen state until suspend completes.
The suspend event triggers ath10k_stop() which again triggers ath10k_halt()
The double invocation of ath10k_halt() causes ath10k_htt_rx_free() to be
called twice(Note: ath10k_htt_rx_alloc was not called by restart worker
thread because of its frozen state), causing the crash.

To fix this, during the suspend flow, skip call to ath10k_halt() in
ath10k_stop() when the current driver state is ATH10K_STATE_RESTARTING.
Also, for driver state ATH10K_STATE_RESTARTING, call
ath10k_wait_for_suspend() in ath10k_stop(). This is because call to
ath10k_wait_for_suspend() is skipped later in
[ath10k_halt() > ath10k_core_stop()] for the driver state
ATH10K_STATE_RESTARTING.

The frozen restart worker thread will be cancelled during resume when the
device comes out of suspend.

Below is the crash stack for reference:

[  428.469167] ------------[ cut here ]------------
[  428.469180] kernel BUG at mm/slub.c:4150!
[  428.469193] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[  428.469219] Workqueue: events_unbound async_run_entry_fn
[  428.469230] RIP: 0010:kfree+0x319/0x31b
[  428.469241] RSP: 0018:ffffa1fac015fc30 EFLAGS: 00010246
[  428.469247] RAX: ffffedb10419d108 RBX: ffff8c05262b0000
[  428.469252] RDX: ffff8c04a8c07000 RSI: 0000000000000000
[  428.469256] RBP: ffffa1fac015fc78 R08: 0000000000000000
[  428.469276] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  428.469285] Call Trace:
[  428.469295]  ? dma_free_attrs+0x5f/0x7d
[  428.469320]  ath10k_core_stop+0x5b/0x6f
[  428.469336]  ath10k_halt+0x126/0x177
[  428.469352]  ath10k_stop+0x41/0x7e
[  428.469387]  drv_stop+0x88/0x10e
[  428.469410]  __ieee80211_suspend+0x297/0x411
[  428.469441]  rdev_suspend+0x6e/0xd0
[  428.469462]  wiphy_suspend+0xb1/0x105
[  428.469483]  ? name_show+0x2d/0x2d
[  428.469490]  dpm_run_callback+0x8c/0x126
[  428.469511]  ? name_show+0x2d/0x2d
[  428.469517]  __device_suspend+0x2e7/0x41b
[  428.469523]  async_suspend+0x1f/0x93
[  428.469529]  async_run_entry_fn+0x3d/0xd1
[  428.469535]  process_one_work+0x1b1/0x329
[  428.469541]  worker_thread+0x213/0x372
[  428.469547]  kthread+0x150/0x15f
[  428.469552]  ? pr_cont_work+0x58/0x58
[  428.469558]  ? kthread_blkcg+0x31/0x31

Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00288-QCARMSWPZ-1
Co-developed-by: Wen Gong <quic_wgong@quicinc.com>
Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Signed-off-by: Abhishek Kumar <kuabhs@chromium.org>
---

Changes in v2:
- Fixed typo, replaced ath11k by ath10k in the comments.
- Adjusted the position of my S-O-B tag.
- Added the Tested-on tag.

 drivers/net/wireless/ath/ath10k/mac.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

Comments

Brian Norris April 27, 2022, 8:27 p.m. UTC | #1 
On Tue, Apr 26, 2022 at 10:20 PM Abhishek Kumar <kuabhs@chromium.org> wrote:
> On Tue, Apr 26, 2022 at 3:34 PM Brian Norris <briannorris@chromium.org> wrote:
> > You could have retained my:
> >
> > Reviewed-by: Brian Norris <briannorris@chromium.org>
> >
> > but no worries; it's just a few characters ;)
> Oh! sorry about that, I was under the impression that if the next
> iteration is posted, then I cannot just add the Reviewed-by tag
> provided in the previous iteration by myself.

You certainly *can* add it, but it's a judgment call on whether you
should. In this case, you were only making cosmetic changes (commit
message and comments, requested by reviewers) between versions, so IMO
that's totally fine. If there are more substantial changes between
versions, it may be better to skip it, and let the reviewer re-review.
Sometimes a reviewer might even explicitly say, "with changes X and Y,
consider this Reviewed-by: foo <foo@bar.tld>", which is a pretty
strong indication you can add it.

Anyway, it's probably better to omit a review line that should have
been included, rather than include one that should not have been
(e.g., because undesirable changes were made). So again, no worries
from me!

Brian
diff mbox series

Patch

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index d804e19a742a..e9c1f11fef0a 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -5345,8 +5345,22 @@  static void ath10k_stop(struct ieee80211_hw *hw)
 
 	mutex_lock(&ar->conf_mutex);
 	if (ar->state != ATH10K_STATE_OFF) {
-		if (!ar->hw_rfkill_on)
-			ath10k_halt(ar);
+		if (!ar->hw_rfkill_on) {
+			/* If the current driver state is RESTARTING but not yet
+			 * fully RESTARTED because of incoming suspend event,
+			 * then ath10k_halt is already called via
+			 * ath10k_core_restart and should not be called here.
+			 */
+			if (ar->state != ATH10K_STATE_RESTARTING)
+				ath10k_halt(ar);
+			else
+				/* Suspending here, because when in RESTARTING
+				 * state, ath10k_core_stop skips
+				 * ath10k_wait_for_suspend.
+				 */
+				ath10k_wait_for_suspend(ar,
+							WMI_PDEV_SUSPEND_AND_DISABLE_INTR);
+		}
 		ar->state = ATH10K_STATE_OFF;
 	}
 	mutex_unlock(&ar->conf_mutex);