[PATCH v3 02/11] ALSA: firewire-lib/motu: use int type for the value of bitwise OR with enumerator-constant

[Takashi Iwai]

On Tue, 18 May 2021 10:13:34 +0200,
Takashi Sakamoto wrote:
> 
> On Tue, May 18, 2021 at 09:02:54AM +0200, Takashi Iwai wrote:
> > On Tue, 18 May 2021 04:43:17 +0200,
> > Takashi Sakamoto wrote:
> > > 
> > > It brings some inconvenience in practice to use enumerated type for
> > > variable to which bitwise OR with enumerator constant is assigned.
> > > 
> > > This commit replaces declarations of enumerated type with int type.
> > 
> > Better to use unsigned int for bit flags.  Otherwise the highest bit
> > becomes harder to use.
> 
> I can't imagine such situation that the signed value causes issue. Would
> I request actual example with such issue? At least, the highest bit is
> still available as bit even if the value is negative by assigning
> 0x80000000...

It's available in signed int, but this is inconvenient, e.g. if you
shift the bit.  Maybe I forgot something else, too.

You may still use signed int if you are sure that you'll never reach
to the highest number, but other than that, using unsigned for bit
flags is a *VERY* common practice in the kernel programming, so there
is no reason to ignore it.


Takashi