Re: [PATCH v4 02/10] ufs: sysfs: device descriptor

From: gregkh@xxxxxxxxxxxxxxxxxxx
Date: Sun Feb 04 2018 - 06:29:17 EST


On Sun, Feb 04, 2018 at 09:03:25AM +0000, Stanislav Nijnikov wrote:
> > -----Original Message-----
> > From: Bart Van Assche
> > Sent: Friday, February 2, 2018 6:32 PM
> > To: gregkh@xxxxxxxxxxxxxxxxxxx
> > Cc: linux-scsi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> > jaegeuk@xxxxxxxxxx; Alex Lemberg <Alex.Lemberg@xxxxxxx>; Stanislav
> > Nijnikov <Stanislav.Nijnikov@xxxxxxx>
> > Subject: Re: [PATCH v4 02/10] ufs: sysfs: device descriptor
> >
> > On Fri, 2018-02-02 at 08:17 +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
> > > On Fri, Feb 02, 2018 at 12:25:46AM +0000, Bart Van Assche wrote:
> > > > On Thu, 2018-02-01 at 18:15 +0200, Stanislav Nijnikov wrote:
> > > > > +enum ufs_desc_param_size {
> > > > > + UFS_PARAM_BYTE_SIZE = 1,
> > > > > + UFS_PARAM_WORD_SIZE = 2,
> > > > > + UFS_PARAM_DWORD_SIZE = 4,
> > > > > + UFS_PARAM_QWORD_SIZE = 8,
> > > > > +};
> > > >
> > > > Please do not copy bad naming choices from the Windows kernel into
> > > > the Linux kernel. Using names like WORD / DWORD / QWORD is much less
> > > > readable than using the numeric constants 2, 4, 8. Hence my proposal
> > > > to leave out the above enum completely.
> > >
> > > Are you sure those do not come from the spec itself? It's been a
> > > while since I last read it, but for some reason I remember those types
> > > of names being in there. But I might be confusing specs here.
> >
> > Hello Greg,
> >
> > That's a good question. However, a quick search on the Internet for the
> > search phrase "Universal Flash Storage" "qword" did not yield any results
> > about UFS in the first ten search hits. And I haven't found any references to
> > the DWORD / QWORD terminology in the "UNIVERSAL FLASH STORAGE HOST
> > CONTROLLER INTERFACE (UFSHCI), UNIFIED MEMORY EXTENSION, Version
> > 1.1" document either. Maybe that means that I was looking at the wrong
> > document?
> >
> > Thanks,
> >
> > Bart.
> >
> >
> The UFS spec 2.1 specifies size as first letter in names of the descriptor parameters and attributes (e.g. bDeviceClass, wSpecVersion, dPSAMaxDataSize, qTotalRawDeviceCapacity, ...). But usage of the enum could be easily removed.

It matches the naming scheme of the spec, so in my opinion, it's fine
as-is. But as I'm not the author here, it's up to you what you want to
use, you have to maintain this, not me :)

thanks,

greg k-h