Re: [PATCH 3/7] soc: aspeed: lpc-snoop: Ensure model_data is valid

[Andrew Jeffery <andrew@codeconstruct.com.au>]

On Wed, 2025-04-16 at 14:19 +0200, Jean Delvare wrote:
> On Fri, 11 Apr 2025 10:38:33 +0930, Andrew Jeffery wrote:
> > of_device_get_match_data() can return NULL, though shouldn't in
> > current
> > circumstances. Regardless, initialise model_data closer to use so
> > it's
> > clear we need to test for validity prior to dereferencing.
> > 
> > Fixes: 2dee584bc9e3 ("drivers/misc: (aspeed-lpc-snoop): Add ast2400
> > to compat")
> > Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
> > ---
> >  drivers/soc/aspeed/aspeed-lpc-snoop.c | 13 +++++++------
> >  1 file changed, 7 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c
> > b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> > index
> > e9d9a8e60a6f062c0b53c9c02e5d73768453998d..28f034b8a3b7226efe20cbe30
> > a7da0c2b49fbd96 100644
> > --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
> > +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> > @@ -186,10 +186,10 @@ static int aspeed_lpc_enable_snoop(struct
> > aspeed_lpc_snoop *lpc_snoop,
> >                                    struct device *dev,
> >                                    int channel, u16 lpc_port)
> >  {
> > -       int rc = 0;
> > +       const struct aspeed_lpc_snoop_model_data *model_data;
> >         u32 hicr5_en, snpwadr_mask, snpwadr_shift, hicrb_en;
> > -       const struct aspeed_lpc_snoop_model_data *model_data =
> > -               of_device_get_match_data(dev);
> > +       int rc = 0;
> > +
> 
> Duplicate blank line.

I'll clean that up.

> 
> >  
> >         if (lpc_snoop->chan[channel].enabled)
> >                 return -EBUSY;
> > @@ -236,9 +236,10 @@ static int aspeed_lpc_enable_snoop(struct
> > aspeed_lpc_snoop *lpc_snoop,
> >         regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en,
> > hicr5_en);
> >         regmap_update_bits(lpc_snoop->regmap, SNPWADR,
> > snpwadr_mask,
> >                            lpc_port << snpwadr_shift);
> > -       if (model_data->has_hicrb_ensnp)
> > -               regmap_update_bits(lpc_snoop->regmap, HICRB,
> > -                               hicrb_en, hicrb_en);
> > +
> > +       model_data = of_device_get_match_data(dev);
> > +       if (model_data && model_data->has_hicrb_ensnp)
> > +               regmap_update_bits(lpc_snoop->regmap, HICRB,
> > hicrb_en, hicrb_en);
> >  
> >         lpc_snoop->chan[channel].enabled = true;
> >  
> > 
> 
> Acked-by: Jean Delvare <jdelvare@suse.de>
> 

Thanks,

Andrew