RE: [PATCH 1/3] staging: comedi: amplc_dio200_common: prevent extra free_irq()

From: Hartley Sweeten
Date: Fri Jul 25 2014 - 14:23:15 EST


On Friday, July 25, 2014 10:07 AM, Ian Abbott wrote:
> `dio200_detach()` in "amplc_dio200.c" calls
> `amplc_dio200_common_detach()` in "amplc_dio200_common.c", followed by
> `comedi_legacy_detach()` in "../drivers.c". Both of those functions
> call `free_irq()` if `dev->irq` is non-zero. The second call produces a
> warning message because the handler has already been freed. Prevent
> that by setting `dev->irq = 0` in `amplc_dio200_common_detach()`.
>
> Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
> ---
> drivers/staging/comedi/drivers/amplc_dio200_common.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/staging/comedi/drivers/amplc_dio200_common.c b/drivers/staging/comedi/drivers/amplc_dio200_common.c
> index 78700e8..3592e58 100644
> --- a/drivers/staging/comedi/drivers/amplc_dio200_common.c
> +++ b/drivers/staging/comedi/drivers/amplc_dio200_common.c
> @@ -1202,8 +1202,10 @@ void amplc_dio200_common_detach(struct comedi_device *dev)
>
> if (!thisboard || !devpriv)
> return;
> - if (dev->irq)
> + if (dev->irq) {
> free_irq(dev->irq, dev);
> + dev->irq = 0;
> + }
> }
> EXPORT_SYMBOL_GPL(amplc_dio200_common_detach);

Ian,

I have already gave a Reviewed-by signoff for this series.

After looking over the code I think a cleaner solution would be to:

1) Use comedi_legacy_detach() directly for the (*detach) in the
legacy ISA driver.
2) Move the code from amplc_dio200_common_detach() into the
(*detach) function for the PCI driver.
3) Remove the exported function amplc_dio200_common_detach().

Regards,
Hartley

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