On Tue, Jan 31, 2023 at 11:19:36AM +0100, Guru Mehar Rachaputi wrote:
> 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.
Do you have this hardware to test with?
> > > 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.
You have to test the existing applications that talk to the device to
ensure that this works properly. This change just breaks the
user/kernel api and doesn't actually change anything to work different
than that :(
thanks,
greg k-h
