Re: [PATCH 1/2] dmaengine: mv_xor_v2: Fix an error code.

[Christophe JAILLET]

Le 29/03/2023 à 12:27, Dan Carpenter a écrit :
> On Sun, Mar 26, 2023 at 09:06:37AM +0200, Christophe JAILLET wrote:
> > If the probe is deferred, -EPROBE_DEFER should be returned, not
> > +EPROBE_DEFER.
> >
> > Fixes: 3cd2c313f1d6 ("dmaengine: mv_xor_v2: Fix clock resource by adding a register clock")
> > Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> > ---
> >   drivers/dma/mv_xor_v2.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
> > index 89790beba305..0991b8265829 100644
> > --- a/drivers/dma/mv_xor_v2.c
> > +++ b/drivers/dma/mv_xor_v2.c
> > @@ -752,7 +752,7 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
> >   
> >   	xor_dev->clk = devm_clk_get(&pdev->dev, NULL);
> >   	if (PTR_ERR(xor_dev->clk) == -EPROBE_DEFER) {
> > -		ret = EPROBE_DEFER;
> > +		ret = -EPROBE_DEFER;
> >   		goto disable_reg_clk;
>
> Heh.  Looking through the Smatch results, I don't think this actually
> affects runtime because driver_probe_device() checks for both positive
> and negatives.  People shouldn't be returning positives, of course, but
> it appears there is a work around for bugs built in already.

Correct, but weird.

I've tried to look at the history of [1], but couldn't find any rational 
for it.

Apparently it was already in the v1 of the serie. [2]

CJ

[1]: 
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=45ddcb42949f825f0caa25352e825cede94b6aba
[2]: https://lore.kernel.org/all/20210614150846.4111871-5-hch@xxxxxx/

> regards,
> dan carpenter