Re: [PATCH v2,5/5] drivers: uio: new driver for fsl_85xx_cache_sram
From: Scott Wood
Date: Thu Apr 16 2020 - 15:38:29 EST
On Thu, 2020-04-16 at 08:30 +0200, Greg KH wrote:
> On Wed, Apr 15, 2020 at 02:27:51PM -0500, Scott Wood wrote:
> > > > + dev_err(&pdev->dev, "error no valid uio-map
> > > > configured\n");
> > > > + ret = -EINVAL;
> > > > + goto err_info_free_internel;
> > > > + }
> > > > +
> > > > + info->version = "0.1.0";
> > >
> > > Could you define some DRIVER_VERSION in the top of the file next to
> > > DRIVER_NAME instead of hard coding in the middle on a function ?
> >
> > That's what v1 had, and Greg KH said to remove it. I'm guessing that he
> > thought it was the common-but-pointless practice of having the driver
> > print a
> > version number that never gets updated, rather than something the UIO API
> > (unfortunately, compared to a feature query interface) expects. That
> > said,
> > I'm not sure what the value is of making it a macro since it should only
> > be
> > used once, that use is self documenting, it isn't tunable, etc. Though if
> > this isn't a macro, UIO_NAME also shouldn't be (and if it is made a macro
> > again, it should be UIO_VERSION, not DRIVER_VERSION).
> >
> > Does this really need a three-part version scheme? What's wrong with a
> > version of "1", to be changed to "2" in the hopefully-unlikely event that
> > the
> > userspace API changes? Assuming UIO is used for this at all, which
> > doesn't
> > seem like a great fit to me.
>
> No driver version numbers at all please, they do not make any sense when
> the driver is included in the kernel tree.
Again, reporting a version string is part of the UIO API. It might not be a
good API, but if it's left as NULL the registration will fail.
-Scott