Re: [Outreachy kernel] Re: [PATCH] staging: octeon-usb: Prefer using BIT macro

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Mon, Oct 03, 2016 at 11:25:27AM +0200, Greg Kroah-Hartman wrote:
> On Mon, Oct 03, 2016 at 11:20:49AM +0300, Aaro Koskinen wrote:
> > Hi,
> > 
> > On Mon, Oct 03, 2016 at 09:01:36AM +0200, Greg Kroah-Hartman wrote:
> > > On Mon, Oct 03, 2016 at 03:03:13AM +0300, Aaro Koskinen wrote:
> > > > On Mon, Oct 03, 2016 at 12:03:25AM +0530, Namrata A Shettar wrote:
> > > > > -	CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_XI		= 1 << 0,
> > > > > -	CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND		= 1 << 1,
> > > > > +	CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_XI		= BIT(0),
> > > > > +	CVMX_USB_INITIALIZE_FLAGS_CLOCK_XO_GND		= BIT(1),
> > > > >  	CVMX_USB_INITIALIZE_FLAGS_CLOCK_MHZ_MASK	= 3 << 3,
> > > > > -	CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ		= 1 << 3,
> > > > > +	CVMX_USB_INITIALIZE_FLAGS_CLOCK_12MHZ		= BIT(3),
> > > > >  	CVMX_USB_INITIALIZE_FLAGS_CLOCK_24MHZ		= 2 << 3,
> > > > >  	CVMX_USB_INITIALIZE_FLAGS_CLOCK_48MHZ		= 3 << 3,
> > > > >  	/* Bits 3-4 used to encode the clock frequency */
> > > > > -	CVMX_USB_INITIALIZE_FLAGS_NO_DMA		= 1 << 5,
> > > > > +	CVMX_USB_INITIALIZE_FLAGS_NO_DMA		= BIT(5),
> > > > 
> > > > All entries should be converted to use BIT.
> > > 
> > > The ones that could be, were, right?  What else should be done here?
> > 
> > 24MHZ is BIT(4).
> 
> Oh yeah, nice catch.
> 
> > > Well, there are bit mask macros now in the kernel tree, perhaps those
> > > should be used, but I don't see how BIT() could be used for "3 << 3", do
> > > you?
> > 
> > BIT(3) | BIT(4)?
> 
> Maybe, but it's not an automatic conversion :)

But it could be, if you use GENMASK() instead, I'm sure you can write up
a transformation rule to do that in an automated way so that you know it
works properly...

thanks,

greg k-h