Re: [PATCH 04/13] ARM: k3: r5: add proper error handling

[Sascha Hauer <s.hauer@pengutronix.de>]

On Mon, Mar 10, 2025 at 07:52:17PM +0100, Marco Felsch wrote:
> On 25-02-28, Sascha Hauer wrote:
> > Add missing error handling in the image loading code. Properly check for
> > errors and panic when mandatory binaries are missing instead of blindly
> > continuing.
> > 
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > ---
> >  arch/arm/mach-k3/r5.c | 57 ++++++++++++++++++++++++++++-----------------------
> >  1 file changed, 31 insertions(+), 26 deletions(-)
> > 
> > diff --git a/arch/arm/mach-k3/r5.c b/arch/arm/mach-k3/r5.c
> > index 2418e9ae73..e12c888afa 100644
> > --- a/arch/arm/mach-k3/r5.c
> > +++ b/arch/arm/mach-k3/r5.c
> > @@ -283,7 +283,7 @@ static int load_fip(const char *filename, off_t offset)
> >  	return 0;
> >  }
> >  
> > -static void do_dfu(void)
> > +static int do_dfu(void)
> >  {
> >  	struct usbgadget_funcs funcs = {};
> >  	int ret;
> > @@ -293,37 +293,24 @@ static void do_dfu(void)
> >  	funcs.dfu_opts = "/fip.img(fip)cs";
> >  
> >  	ret = usbgadget_prepare_register(&funcs);
> > -	if (ret)
> > -		goto err;
> > +	if (ret) {
> > +		pr_err("DFU failed with: %pe\n", ERR_PTR(ret));
> > +		return ret;
> > +	}
> >  
> >  	while (1) {
> >  		ret = stat("/fip.img", &s);
> >  		if (!ret) {
> >  			printf("Downloaded FIP image, DFU done\n");
> > -			load_fip("/fip.img", 0);
> > -			break;
> > +			ret = load_fip("/fip.img", 0);
> > +			if (!ret)
> > +				return 0;
> >  		}
> >  
> >  		command_slice_release();
> >  		mdelay(50);
> >  		command_slice_acquire();
> >  	};
> > -
> > -	return;
> > -
> > -err:
> > -	pr_err("DFU failed with: %pe\n", ERR_PTR(ret));
> > -}
> > -
> > -static int load_images(void)
> > -{
> > -	int err;
> > -
> > -	err = load_fip("/boot/k3.fip", 0);
> > -	if (!err)
> > -		return 0;
> > -
> > -	return 0;
> >  }
> 
> Removing load_images should go into patch-3.

I deliberately did it in this patch because load_images already does
error checking, but up to now the return value of load_images() wasn't
checked. By doing it like you suggest I would either end up calling
load_fip() without checking the error, or I would introduce an
incomplete error checking in k3_r5_start_image() where the return value
of load_fip() is checked, but not the return values of do_dfu and
load_fip_emmc().

> >  static int load_fip_emmc(void)
> > @@ -332,6 +319,7 @@ static int load_fip_emmc(void)
> >  	struct mci *mci;
> >  	char *fname;
> >  	const char *mmcdev = "mmc0";
> > +	int ret;
> 
> Nit: Sometimes you do use ret, sometimes err. I would like to align it
> if possible.

Changed to 'ret' consistently.

Sascha

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