On Tue, Jan 31, 2023 at 06:22:23AM +0100, Greg Kroah-Hartman wrote:
> On Tue, Jan 31, 2023 at 03:11:38AM +0100, Guru Mehar Rachaputi wrote:
> > (struct pi433_tx_cfg)->bit_rate is modified from u16 to u32 to
> > support bit rates up to 300kbps per the spec
>
> What spec?
>
> And how can changing the size of a variable that crosses the user/kernel
> boundry like this change the bit rate max?
>
Honestly, I followed the TODO file suggestion.
> >
> > Signed-off-by: Guru Mehar Rachaputi <gurumeharrachaputi@xxxxxxxxx>
> > ---
> > drivers/staging/pi433/pi433_if.h | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/staging/pi433/pi433_if.h b/drivers/staging/pi433/pi433_if.h
> > index 25ee0b77a32c..1f8ffaf02d99 100644
> > --- a/drivers/staging/pi433/pi433_if.h
> > +++ b/drivers/staging/pi433/pi433_if.h
> > @@ -51,7 +51,7 @@ enum option_on_off {
> > #define PI433_TX_CFG_IOCTL_NR 0
> > struct pi433_tx_cfg {
> > __u32 frequency;
> > - __u16 bit_rate;
> > + __u32 bit_rate;
> > __u32 dev_frequency;
> > enum modulation modulation;
> > enum mod_shaping mod_shaping;
>
> And didn't you just break existing userspace code? If not, how? If so,
> how did you test this?
>
My apologies, I did not study code. While testing, the probe function of
pi433 driver didn't appear in the lsmod operation. I suspected my
testing was wrong.
> thanks,
>
> greg k-h
