On Thursday 02 August 2007, Alan Stern wrote:
> On Thu, 2 Aug 2007, David Brownell wrote:
>
> > Clean up the file storage gadget, using newer APIs and conventions:
> >
> > - gadget_is_dualspeed() and gadget_is_otg() ... #ifdef removal
> >
> > - Remove many now-needless #includes
> >
> > - Use the DEBUG (from Kconfig+Makefile) and VERBOSE_DEBUG conventions.
> >
> > - Remove some "sparse" warnings (it still dislikes the __user annotations)
> >
> > This gave only a minor object code shrinkage.
>
> I'd rather expect to see a minor increase in object code size, since a
> few data structures and lines of code are now compiled in that
> previously would have been #ifdef'ed out.
GCC dead code optimization ensures they don't cluter up
the generated object code. Briefly, in;
static struct ... somedata = { ... };
static void fn1(...) { accesses somedata }
void fn2(...)
{
...
if (0)
fn1(...);
...
}
then fn2() will be in the object, but not fn1 or somedata.
> Why do you think the code size shrank?
In this case, because runtime "is this an OTG gadget?" test
was replaced by a compile time "of course not, it couldn't be"
result ... so GCC could detect the dead code.
> > --- g26.orig/drivers/usb/gadget/file_storage.c 2007-08-01
> > 23:16:10.000000000 -0700
> > +++ g26/drivers/usb/gadget/file_storage.c 2007-08-01 23:29:00.000000000
> > -0700
> > @@ -289,57 +275,51 @@ MODULE_LICENSE("Dual BSD/GPL");
> >
> >
> > /*-------------------------------------------------------------------------*/
> >
> > -#define xprintk(f,level,fmt,args...) \
> > - dev_printk(level , &(f)->gadget->dev , fmt , ## args)
> > #define yprintk(l,level,fmt,args...) \
> > dev_printk(level , &(l)->dev , fmt , ## args)
>
> Is there any particular reason you expanded xprintk inline but not
> yprintk?
Because I was doing a quick conversion, copy/paste from other
code where the "xprintk" thing got removed. You're right that
there's still additional cleanup that can be done.
> Despite these questions, ACK.
Thanks.
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