Re: [PATCH] mwifiex: Using %*phD instead of print_hex_dump_bytes

[Andrei Emeltchenko <Andrei.Emeltchenko.news@gmail.com>]

Hi Andy,

On Fri, Oct 05, 2012 at 10:00:28AM +0300, Andy Shevchenko wrote:
> On Fri, 2012-10-05 at 09:53 +0300, Andy Shevchenko wrote: 
> > On Thu, 2012-10-04 at 09:32 -0700, Joe Perches wrote: 
> > > On Thu, 2012-10-04 at 12:16 +0300, Andrei Emeltchenko wrote:
> > > > From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
> > > > 
> > > > Make output more readable and remove unneeded function call.
> > > > 
> > > > ...
> > > > mwifiex_sdio mmc0:0001:1: last_cmd_index = 3
> > > > last_cmd_id: 00000000: 28 00 28 00 28                            (.(.(
> > > > ...
> > > > 
> > > > would be changed to:
> > > > 
> > > > ...
> > > > mwifiex_sdio mmc0:0001:1: last_cmd_index = 3
> > > > mwifiex_sdio mmc0:0001:1: last_cmd_id: 28 00 28 00 28
> > > > ...
> > > 
> > > (added Andy Shevchenko)
> > > 
> > > Hi Andrei.  That's probably a better output style too
> > > as the ascii isn't likely useful.
> > > 
> > > One non-nit as a style issue for Andy Shevchenko:
> > > 
> > > > diff --git a/drivers/net/wireless/mwifiex/cmdevt.c b/drivers/net/wireless/mwifiex/cmdevt.c
> > > []
> > > > @@ -917,21 +917,20 @@ mwifiex_cmd_timeout_func(unsigned long function_context)
> > > []
> > > > +		dev_err(adapter->dev, "last_cmd_id: %*ph\n", DBG_CMD_NUM,
> > > > +			adapter->dbg.last_cmd_id);
> > > > +		dev_err(adapter->dev, "last_cmd_act: %*ph\n", DBG_CMD_NUM,
> > > > +			adapter->dbg.last_cmd_act);
> > > 
> > > When the number of bytes is fixed, it might be nicer
> > > to use a format like "%<num>ph" so that the function
> > > argument stack doesn't have the width pushed but it's
> > > fixed in the format.
> > > 
> > > This case would definitely not work well though as it's
> > > a #define rather than a simple number and I think
> > > using "%" stringize(some_define) "ph" is not nice.
> > > 
> > > Maybe this case argues more for always using "%*ph".
> > > At least that's easily greppable.
> > > 
> > > Andy?
> > First of all, the current linux-next has at least two definitions of
> > that constant:
> > drivers/net/wireless/mwifiex/ioctl.h:175:#define DBG_CMD_NUM    5
> > drivers/net/wireless/mwifiex/main.h:118:#define DBG_CMD_NUM 5
> > 
> > I checked briefly the code and found that the constant is heavily used
> > as a definition for the length of static byte arrays. So, in that case
> > probably better to use %*ph, but apply sizeof(cool_var) instead of
> (int)sizeof(cool_var) of course
> 
> > putting constant there.
> 
> And one finding more: buffers are defined as u16. I'm afraid the both
> previous and proposed versions are printing something interesting, like
> only half of the defined data.

The patch only changes printing format. The other logical change would
come better in other patch, maybe Bing could comment here.

Best regards 
Andrei Emeltchenko