6.6-stable review patch. If anyone has any objections, please let me know.
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From: Baochen Qiang quic_bqiang@quicinc.com
[ 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 --- 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 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);