From: Baochen Qiang <quic_bqiang@quicinc.com>
To: <ath11k@lists.infradead.org>
Cc: <linux-wireless@vger.kernel.org>
Subject: [PATCH] wifi: ath11k: fix race due to setting ATH11K_FLAG_EXT_IRQ_ENABLED too early
Date: Fri, 17 Nov 2023 08:39:19 +0800 [thread overview]
Message-ID: <20231117003919.26218-1-quic_bqiang@quicinc.com> (raw)
We are seeing below error randomly in the case where only
one MSI vector is configured:
kernel: ath11k_pci 0000:03:00.0: wmi command 16387 timeout
The reason is, currently, in ath11k_pcic_ext_irq_enable(),
ATH11K_FLAG_EXT_IRQ_ENABLED is set before NAPI is enabled.
This results in a race condition: after
ATH11K_FLAG_EXT_IRQ_ENABLED is set but before NAPI enabled,
CE interrupt breaks in. Since IRQ is shared by CE and data
path, ath11k_pcic_ext_interrupt_handler() is also called
where we call disable_irq_nosync() to disable IRQ. Then
napi_schedule() is called but it does nothing because NAPI
is not enabled at that time, meaning
ath11k_pcic_ext_grp_napi_poll() will never run, so we have
no chance to call enable_irq() to enable IRQ back. Finally
we get above error.
Fix it by setting ATH11K_FLAG_EXT_IRQ_ENABLED after all
NAPI and IRQ work are done. With the fix, we are sure that
by the time ATH11K_FLAG_EXT_IRQ_ENABLED is set, NAPI is
enabled.
Note that the fix above also introduce some side effects:
if ath11k_pcic_ext_interrupt_handler() breaks in after NAPI
enabled but before ATH11K_FLAG_EXT_IRQ_ENABLED set, nothing
will be done by the handler this time, the work will be
postponed till the next time the IRQ fires.
Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23
Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
---
drivers/net/wireless/ath/ath11k/pcic.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ath/ath11k/pcic.c b/drivers/net/wireless/ath/ath11k/pcic.c
index 16d1e332193f..e602d4130105 100644
--- a/drivers/net/wireless/ath/ath11k/pcic.c
+++ b/drivers/net/wireless/ath/ath11k/pcic.c
@@ -460,8 +460,6 @@ void ath11k_pcic_ext_irq_enable(struct ath11k_base *ab)
{
int i;
- set_bit(ATH11K_FLAG_EXT_IRQ_ENABLED, &ab->dev_flags);
-
for (i = 0; i < ATH11K_EXT_IRQ_GRP_NUM_MAX; i++) {
struct ath11k_ext_irq_grp *irq_grp = &ab->ext_irq_grp[i];
@@ -471,6 +469,8 @@ void ath11k_pcic_ext_irq_enable(struct ath11k_base *ab)
}
ath11k_pcic_ext_grp_enable(irq_grp);
}
+
+ set_bit(ATH11K_FLAG_EXT_IRQ_ENABLED, &ab->dev_flags);
}
EXPORT_SYMBOL(ath11k_pcic_ext_irq_enable);
base-commit: 9a36440d929d134c56030a8492405708a143f580
--
2.25.1
--
ath11k mailing list
ath11k@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/ath11k
next reply other threads:[~2023-11-17 0:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-17 0:39 Baochen Qiang [this message]
2023-11-17 1:30 ` [PATCH] wifi: ath11k: fix race due to setting ATH11K_FLAG_EXT_IRQ_ENABLED too early Jeff Johnson
2023-11-30 17:04 ` Kalle Valo
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231117003919.26218-1-quic_bqiang@quicinc.com \
--to=quic_bqiang@quicinc.com \
--cc=ath11k@lists.infradead.org \
--cc=linux-wireless@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).