On Wed, 2012-03-14 at 10:23 +0100, Julia Lawall wrote:
>
> On Wed, 14 Mar 2012, Guan Xuetao wrote:
>
> > On Wed, 2012-03-14 at 11:19 +0300, Dan Carpenter wrote:
> >> On Wed, Mar 14, 2012 at 04:07:24PM +0800, Guan Xuetao wrote:
> >>> puv3_init_dma() is called ONCE when initializing.
> >>> In logical, if request_irq(IRQ_DMAERR, *) failed, free_irq(IRQ_DMA, *)
> >>> is unnecessary, and dma device/driver can keep on working.
> >>> The patch could be:
> >>> ret = request_irq(IRQ_DMAERR, dma_err_handler, 0, "DMAERR", NULL);
> >>> if (ret) {
> >>> printk(KERN_CRIT "Can't register IRQ for DMAERR\n");
> >>> - free_irq(IRQ_DMA, "DMA");
> >>> return ret;
> >>> }
> >>
> >> It seems like you should remove the error return as well?
> >>
> >> regards,
> >> dan carpenter
> >>
> > The error return value will only generate an extra warning message, and
> > have no side-effect.
>
> The whole thing seems a little strange. I guess your point is that the
> call site never looks at the return value? Wouldn't it be better to make
> there be no return value in that case? If there is a return value, some
> calling context in the future might take that into account and then the
> lack of a free_irq would be a memory leak. Also if the first request_irq
> can never fail, perhaps that should be made explicit by not testing the
> return value?
>
> julia
This function is an init_call, not a probe function, and it is only
called ONCE.
The dma device here has two interrupts, one IRQ_DMA, another IRQ_DMAERR.
And the device could work without IRQ_DMAERR.
The return value should indicate whether there is something wrong during
initialization, so the function needs return errno when any request_irq
is failed.
For the first request_irq, some code has prepared its resources before
this call, so I suppose it successful. However, the return value must be
tested.
Regards,
Guan Xuetao
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