Messages in this thread | | | Date | Sat, 19 Sep 2015 22:24:15 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH] genirq: Fix bad IRQ_ONSHOT in forced IRQ setting |
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On Sun, 20 Sep 2015, Kohji Okuno wrote: > From: Thomas Gleixner <tglx@linutronix.de> > Date: Fri, 18 Sep 2015 16:46:24 +0200 > > On Fri, 18 Sep 2015, Kohji Okuno wrote: > >> > >> 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? > > > > Ah, that explains it. Let me think about it a bit. > > If something is not clear please let me know. > By the way, even if other issue exists, we should change > irq_setup_forced_threading() as my patch, I think.
No, we can't. We can only do that if the interrupt is not shared.
Assume the following scenario:
request_irq(irq, handler, IRQF_SHARED, "devA", devidA);
In case of force threading that sets the oneshot flag for the irq descriptor.
Now the sdhci driver is initialized
request_thread_irq(irq, handler, thandler, IRQF_SHARED, "sdhci", devidSDHCI);
The oneshot flag sticks and you run into exactly the same issue as now.
Shared interrupts are a major pain, but we have to deal with them.
I'm working on a solution for that issue.
Thanks,
tglx
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