Re: [PATCH] staging: pi433: #define shift constants in rf69.c

[Josh Abraham]

On Wed, Nov 08, 2017 at 02:52:30PM +0300, Dan Carpenter wrote:
> On Wed, Nov 08, 2017 at 06:25:06AM -0500, Joshua Abraham wrote:
> > This patch completes TODO improvements in rf69.c to change shift
> > constants to a define.
> > 
> > Signed-off-by: Joshua Abraham <j.abraham1776@xxxxxxxxx>
> > ---
> >  drivers/staging/pi433/rf69.c           | 4 ++--
> >  drivers/staging/pi433/rf69_registers.h | 4 ++++
> >  2 files changed, 6 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/staging/pi433/rf69.c b/drivers/staging/pi433/rf69.c
> > index e69a2153c999..cfcace195be9 100644
> > --- a/drivers/staging/pi433/rf69.c
> > +++ b/drivers/staging/pi433/rf69.c
> > @@ -102,7 +102,7 @@ enum modulation rf69_get_modulation(struct spi_device *spi)
> >  
> >  	currentValue = READ_REG(REG_DATAMODUL);
> >  
> > -	switch (currentValue & MASK_DATAMODUL_MODULATION_TYPE >> 3) { // TODO improvement: change 3 to define
> > +	switch (currentValue & MASK_DATAMODUL_MODULATION_TYPE >> SHIFT_DATAMODUL_MODE) {
> 
> You've send a few of mechanical patches without waiting for feedback and
> you should probably slow down...
> 

Understood. I am just excited about submitting patches.

> The first thing to notice is that the original code is probably buggy
> and needs parenthesis.
> 
> 	switch ((currentValue & MASK_DATAMODUL_MODULATION_TYPE) >> 3) {
> 
> But that still doesn't fix the problem that x18 >> 3 is never going to
> equal to DATAMODUL_MODULATION_TYPE_OOK which is 0x8...  So there are a
> couple bugs here.
> 
> The line is over 80 characters, so checkpatch will complain about your
> patch.  Please run checkpatch.pl on all your patches.  Really, I hate
> all the naming here...  Surely we can think of a better name than
> MASK_DATAMODUL_MODULATION_TYPE?  Normally the "MASK" and "SHIFT" part of
> the name go at the end instead of the start.
> 

I named the define to be consistent with the extant code, but I agree
that the names could be better.

> >  /* RegDataModul */
> > +#define  SHIFT_DATAMODUL_MODE				0x03
> > +
> >  #define  MASK_DATAMODUL_MODE			0x06
> 
> Why did you add a blank line?  Don't use hex values for shifting, use
> normal numbers.  The 0x3 is indented too far.
> 

I added the blank line to separate shifts from masks, but since the shift
will only be performed on the mask I supposed it isn't needed.

> Anyway, take your time and really think about patches before you send
> them.  Normally, I write a patch, then wait overnight, then review it
> and again in the morning before I send it.
> 
> regards,
> dan carpenter
> 

Thanks for the criticism.  I will be better.