Messages in this thread | | | Date | Mon, 17 Dec 2012 17:06:43 +0100 | From | Marcos Lois Bermúdez <> | Subject | Re: Question about using new request_threaded_irq |
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Hi,
I lot of thanks for you fast reply. It seem that i swap the mean of handler parameters, so i now see it correct. :).
Excuse for my newbie question.
handler is the primary handler, and if NULL a default primary handler is installed, and thread_fn is the thread handler.
I'm a bit confusing because i see a outdated page that talks about this new IRQ API, but now i see that it's very outdated:
http://lwn.net/Articles/302043/
Regards.
El 17/12/2012 16:37, Jonathan Corbet escribió: > On Mon, 17 Dec 2012 16:11:22 +0100 > Marcos Lois Bermúdez <marcos.discalis@gmail.com> wrote: > >> For my understand if i call for example: >> >> request_threaded_irq(irqmum, NULL, irq_handle, IRQF_TRIGGER_FALLING, >> DEVICE_NAME, priv); >> >> This seem to make a old Hard IRQ handler, and inside of this handler >> sleep APIs can't be used, but i see some SPI drivers that seem to >> register a IRQ of this form and make API calls that can sleep in the >> handler. > > Not quite. The prototype for request_threaded_irq() is: > > int request_threaded_irq(unsigned int irq, irq_handler_t handler, > irq_handler_t thread_fn, unsigned long irqflags, > const char *devname, void *dev_id) > > Note the presents of *two* handlers, called "handler" and "thread_fn". > The first, "handler", is called in interrupt context; it's job is usually > to quiet the device and return; it cannot sleep. If it's return value is > IRQ_WAKE_THREAD, the thread_fn() will be called in process context; it > *can* sleep. In the example you cite, there is no immediate handler, only > the thread_fn(); the call to a blocking function from within the > thread_fn() is correct. > > Hope that helps, > > jon > > Jonathan Corbet / LWN.net / corbet@lwn.net >
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