English is also my mother language.
i think your handle should check your device interrupt status
register,check if this interrupt is yours or others.if yours,handle it
.if others,should return IRQ_NONE.
But your code :
// find out which board got an interrupt
for (i = 0; i < MAX_BOARDS; i++)
if (dev_id == &my_boards[i]) {
board = dev_id;
break;
}
// Check if interrupt was issued by another device (in case of shared
// interrupt line).
if (i == MAX_BOARDS)
goto handled;
if (board == NULL)
goto handled;
Maybe scenario is wrong.Others come in a interrupt ,your handle dev_id
== my_boards[0]
,so i == 0 && board !=NULL so not jump to your label handled.
So i think your condition to check maybe is wrong.you only should
check your device interrupt status register flag-bit.
2009/2/25 Denis Borisevich <dennisfen@xxxxxxxxx>:
> Hi!
> I've done some tests and here is what I figured out: the interrupts
> assigned to the device controlled by the ahci driver keep going even
> without my driver loaded and even with all my boards removed from
> system physically. So it seems that everything ok.
> But I have another question concerning interrupts:
> Let's take the situation I described in my first and second posts - I
> have a system with the PCI board which I develop driver for. This
> board shares interrupt with the device controlled by ahci driver. The
> question is why every interrupt I got on this line is interpreted by
> my driver as the interrupt which belongs to it? Here is the code I
> use:
>
> === CODE BELOW ===
>
> to register ISR:
> struct my_dev *board;
> request_irq(board->irq, my_interrupt_handler, IRQF_SHARED, "my_module", board);
>
> ISR:
> static irqreturn_t my_interrupt_handler(int irq, void *dev_id)
> {
> struct my_dev *board;
> int i, retval = IRQ_NONE;
>
> // find out which board got an interrupt
> for (i = 0; i < MAX_BOARDS; i++)
> if (dev_id == &my_boards[i]) {
> board = dev_id;
> break;
> }
>
> // Check if interrupt was issued by another device (in case of shared
> // interrupt line).
> if (i == MAX_BOARDS)
> goto handled;
> if (board == NULL)
> goto handled;
>
> // if we are here then it's our interrupt
> retval = IRQ_HANDLED;
>
> /* here goes some checks on the device registers
> to know if there is interrupts pending in it.
> these checks are sure to be right. If there's no
> interrupt, then debug message "no interrupt" is
> printed.
> */
> .......
> /* here goes the interrupt handling, if the previous check
> was successful
> */
> .......
>
> handled:
> return retval;
> }
>
> === CODE ABOVE ===
>
> So, what do I have now. When no program touches my device (it is
> idling) and the ahci driver is loaded I have this "no interrupt"
> message in dmesg output 20-30 times per second. When some application
> uses my device I have the proper printouts (the kind of interrupt and
> so on) and bunch of these "no interrupt". When I install my board into
> another PCI slot (and get another interrupt line) I never see these
> "no interrupt" messages, but only the ones concerning to the actual
> interrupt handling in my driver. Which indicates that driver works as
> intended. The questions is why the dev_id parameter of
> my_interrupt_handler() holds the data which belongs to one of the
> boards controlled by my driver (which is the reason why the check in
> the very beginning of ISR routine is passed)?
>
> P.S.: I hope that you got what I tried to explain=) English is not my
> native language=)
>
> --
> Denis
>
> --
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