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authorBaochen Qiang <quic_bqiang@quicinc.com>2023-11-17 08:39:19 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-02-05 20:14:20 +0000
commit5b34e76bbaab1e011c912c0170e1fe69bfedb2b3 (patch)
treed364d816e3621d0c4839aba3f15020d6e946bc05
parente4f4bac7d3b64eb75f70cd3345712de6f68a215d (diff)
wifi: ath11k: fix race due to setting ATH11K_FLAG_EXT_IRQ_ENABLED too early
[ Upstream commit 5082b3e3027eae393a4e86874bffb4ce3f83c26e ] 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> Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com> Link: https://lore.kernel.org/r/20231117003919.26218-1-quic_bqiang@quicinc.com Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/net/wireless/ath/ath11k/pcic.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/wireless/ath/ath11k/pcic.c b/drivers/net/wireless/ath/ath11k/pcic.c
index c63083633b37..011cf5fb8023 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);