Summary:
- During Wi-Fi audio streaming test, I found a deadlock in nxtask_exit()
- Actually, nxtask_exit() was called and tried to enter critical section
- In enter_critical_section(), there is a deadlock avoidance logic
- However, if switched to a new rtcb with irqcount=0, the logic did not work
- Because the 2nd critical section was treated as if it were the 1st one
- Actually, it tried to run the deadlock avoidance logic
- But nxtask_exit() was called with critical section (i.e. IRQ already disabled)
- So the logic did not work as expected because up_irq_restore() did not enable the IRQ.
- This commit fixes this issue by incrementing irqcount before calling nxtask_terminate()
- Also it adjusts g_cpu_irqlock and g_cpu_lockset
Impact:
- Affects SMP only
Testing:
- Tested with spresense:wifi_smp (smp, ostest, nxplayer, telnetd)
- Tested with sabre-6quad:smp with QEMU (smp, ostest)
- Tested with maix-bit:smp with QEMU (smp, ostest)
- Tested with esp32-core:smp with QEMU (smp, ostest)
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>