Messages in this thread | | | Date | Fri, 18 Sep 2015 19:56:45 +0900 | Subject | Re: [PATCH] genirq: Fix bad IRQ_ONSHOT in forced IRQ setting | From | Kohji Okuno <> |
| |
From: Marc Zyngier <marc.zyngier@arm.com> Date: Fri, 18 Sep 2015 11:03:12 +0100 > On Fri, 18 Sep 2015 18:22:07 +0900 > Kohji Okuno <okuno.kohji@jp.panasonic.com> wrote: > >> From: Thomas Gleixner <tglx@linutronix.de> >> Date: Fri, 18 Sep 2015 11:04:23 +0200 >> > That's weird. The flow is: >> > >> > interrupt() >> > mask() >> > ret = primary_handler() >> > if (ret == WAKE_THREAD) >> > wake_thread() >> > else >> > unmask() >> > >> > thread_handler() >> > .... >> > unmask() >> > >> > So if an interrupt is triggered on the device while the interrupt is >> > masked it should be raised again immediately when the unmask happens >> > because its level type. >> > >> > I'm wondering why that doesn't work. >> >> Yes. I think so. And, I have just found that sdhci_thread_irq() don't >> finish in this case. I'm analyzing about this now. But, after I apply >> my patch, sdhci_thread_irq() can finish. I will share the result with >> you. > > What do you mean exactly by "don't finish"? Does it hang somewhere? Or > keeps processing data but never drains? > > Thanks, > > M.
Hi Marc and tglx,
irq thread(runs sdhci_thread_irq()) is waiting on drivers/mmc/core/core.c:mmc_wait_for_req_done() in order to access a SDIO register. And, this thread shoud be woken up from sdhci_irq() after the completion of the register access. But, since the IRQ is masked, sdhci_irq() is not called and irq thread can not wake up. This is root cause, I think. What do you think about this?
Best regards, Kohji Okuno
| |