Re: [PATCH v1 1/1] gpio: pca953x: enfore type for i2c_smbus_write_word_data()

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Wed, 2016-06-01 at 12:44 +0800, Yong Li wrote:
> Hi Andy,
> 
> Could you let me know which build system you are using? I am using
> Ubuntu 1604(64 bit) to build the kernel source, but I did not find the
> warning.

Hmm... I'm confused what exactly you are asking here. My host system is
Debian unstable, kernel is built by it's own KBuild infrastructure.

I'm pretty sure you are talking about this:

https://lwn.net/Articles/205624/

> 
> Thanks,
> Yong
> 
> 2016-06-01 3:03 GMT+08:00 Andy Shevchenko <andriy.shevchenko@linux.int
> el.com>:
> > The commit 9b8e3ec34318 ("gpio: pca953x: Use correct u16 value for
> > register
> > word write") fixed regression in pca953x_write_regs(). At the same
> > time the
> > solution introduced a sparse warning:
> > 
> > drivers/gpio/gpio-pca953x.c:168:39: warning: incorrect type in
> > argument 3 (different base types)
> > drivers/gpio/gpio-pca953x.c:168:39:    expected unsigned short
> > [unsigned] [usertype] value
> > drivers/gpio/gpio-pca953x.c:168:39:    got restricted __le16
> > [usertype] <noident>
> > 
> > Fix the code by enforcing the type of i2c_smbus_write_word_data()
> > parameter.
> > 
> > Cc: Yong Li <sdliyong@gmail.com>
> > Cc: Phil Reid <preid@electromag.com.au>
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > ---
> >  drivers/gpio/gpio-pca953x.c | 9 ++++++---
> >  1 file changed, 6 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-
> > pca953x.c
> > index d8233be..21b21cd 100644
> > --- a/drivers/gpio/gpio-pca953x.c
> > +++ b/drivers/gpio/gpio-pca953x.c
> > @@ -163,10 +163,13 @@ static int pca953x_write_regs(struct
> > pca953x_chip *chip, int reg, u8 *val)
> >                                         NBANK(chip), val);
> >         } else {
> >                 switch (chip->chip_type) {
> > -               case PCA953X_TYPE:
> > -                       ret = i2c_smbus_write_word_data(chip-
> > >client,
> > -                           reg << 1, cpu_to_le16(get_unaligned((u16
> > *)val)));
> > +               case PCA953X_TYPE: {
> > +                       __le16 word = cpu_to_le16(get_unaligned((u16
> > *)val));
> > +
> > +                       ret = i2c_smbus_write_word_data(chip-
> > >client, reg << 1,
> > +                                                       (__force
> > u16)word);
> >                         break;
> > +               }
> >                 case PCA957X_TYPE:
> >                         ret = i2c_smbus_write_byte_data(chip-
> > >client, reg << 1,
> >                                                         val[0]);
> > --
> > 2.8.1
> > 

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy
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