Hans> Hello, I noticed the change in request_irq and free_irq
Hans> together with the introduction of shared interrupts.
Hans> As writing a section of the Kernel Korner in Linux Journal,
Hans> I wondered what the new "device id" meant.
Hans> As Shared Interrupts are a concept supported by PCI, which
Hans> introduces device ids as well, I saw those to concepts
Hans> together and believed that the device id should is only
Hans> useful when SA_SHIRQ is set (when calling
Hans> request_irq). Howether, when looking at patch-1.3.74.gz, I
Hans> noticed that the calls to "request_irq" and "free_irq" don't
Hans> support shared irqs, but anyway set the device id. This
Hans> should not be harmful, but who understood the new
Hans> irq-concept wrong, me or the "patcher"?
Beeing pratical, the new dev_id field adds a new void * to the irq
action struture that is very handy to use in device drivers even if
you are not sharing interrupts since it allows you to get a pointer to
your dev struture without going through an irq_to_dev map (these days
device drivers are designed to support multiple instances of a
driver).
I've checked the code and it seams to me that the kernel doesn't make
any assumptions on the dev_id field so is up to the driver to use it
as a pointer to whatever it wants....
I can be wrong of course....
regards,
Pedro.