Re: [PATCH] usb: bdc: Remove duplicate error message in bdc_probe()

[Tang Bin]

Hi Balbi：

在 2020/9/28 17:40, Felipe Balbi 写道:
> Hi,
>
> Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx> writes:
> > Hi Greg KH:
> >
> > 在 2020/9/27 21:45, Greg KH 写道:
> > > On Sun, Sep 27, 2020 at 09:42:18PM +0800, Tang Bin wrote:
> > > > In this function, we don't need dev_err() message because
> > > > when something goes wrong, devm_platform_ioremap_resource()
> > > > can print an error message itself, so remove the redundant
> > > > one.
> > > >
> > > > Signed-off-by: Zhang Shengju <zhangshengju@xxxxxxxxxxxxxxxxxxxx>
> > > > Signed-off-by: Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx>
> > > > ---
> > > >    drivers/usb/gadget/udc/bdc/bdc_core.c | 4 +---
> > > >    1 file changed, 1 insertion(+), 3 deletions(-)
> > > >
> > > > diff --git a/drivers/usb/gadget/udc/bdc/bdc_core.c b/drivers/usb/gadget/udc/bdc/bdc_core.c
> > > > index 02a3a7746..9454f179e 100644
> > > > --- a/drivers/usb/gadget/udc/bdc/bdc_core.c
> > > > +++ b/drivers/usb/gadget/udc/bdc/bdc_core.c
> > > > @@ -508,10 +508,8 @@ static int bdc_probe(struct platform_device *pdev)
> > > >    	bdc->clk = clk;
> > > >    
> > > >    	bdc->regs = devm_platform_ioremap_resource(pdev, 0);
> > > > -	if (IS_ERR(bdc->regs)) {
> > > > -		dev_err(dev, "ioremap error\n");
> > > > +	if (IS_ERR(bdc->regs))
> > > >    		return -ENOMEM;
> > > Why not return the error given to us?
> > Because when get ioremap failed, devm_platform_ioremap_resource() can
> > print error message
> >
> > "dev_err(dev, "ioremap failed for resource %pR\n", res)" in it's called
> > function. So I think this's place's
> >
> > dev_err(dev, "ioremap error\n") is redundant.
> that's not what Greg point you at, though. Greg's concern is valid in
> that instead of passing along the error within bdc->regs, you always
> return -ENOMEM. OTW, your code should read like so:
>
> 	if (IS_ERR(bdc->regs))
>          	return PTR_ERR(bdc->regs);

Thanks for your explain，when I send the patch yesterday, my point is at 
dev_err(), and not aimed at IS_ERR() & PTR_ERR(),

if it's Greg's point, I will change this patch after his reply.


Thank you very much.

Tang Bin