On 11/16/2023 4:39 PM, Baochen Qiang wrote: > 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@xxxxxxxxxxx> Acked-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>
