On Sun, Jan 06, 2013 at 11:57:48AM -0800, Dmitry Torokhov wrote:
> On Sun, Jan 06, 2013 at 08:27:39PM +0100, Thierry Reding wrote:
> > On Sat, Jan 05, 2013 at 12:06:58AM -0800, Dmitry Torokhov wrote:
> > > On Sat, Jan 05, 2013 at 01:15:08PM +0530, Laxman Dewangan wrote:
> > [...]
> > > > @@ -735,25 +738,16 @@ static int tegra_kbc_probe(struct platform_device
> > > > *pdev)
> > > > spin_lock_init(&kbc->lock);
> > > > setup_timer(&kbc->timer, tegra_kbc_keypress_timer, (unsigned
> > > > long)kbc);
> > > >
> > > > - res = request_mem_region(res->start, resource_size(res),
> > > > pdev->name);
> > > > - if (!res) {
> > > > - dev_err(&pdev->dev, "failed to request I/O memory\n");
> > > > - err = -EBUSY;
> > > > - goto err_free_mem;
> > > > - }
> > > > -
> > > > - kbc->mmio = ioremap(res->start, resource_size(res));
> > > > + kbc->mmio = devm_request_and_ioremap(&pdev->dev, res);
> > > > if (!kbc->mmio) {
> > > > - dev_err(&pdev->dev, "failed to remap I/O memory\n");
> > > > - err = -ENXIO;
> > > > - goto err_free_mem_region;
> > > > + dev_err(&pdev->dev, "Cannot request memregion/iomap
> > > > address\n");
> > > > + return -EADDRNOTAVAIL;
> > >
> > > Erm, no, -EBUSY please.
> >
> > EADDRNOTAVAIL is the canonical error for devm_request_and_ioremap()
> > failure. The kerneldoc comment in lib/devres.c even gives a short
> > example that uses this error code.
>
> I am sorry, but I do not consider a function that was added a little
> over a year ago as a canon. If you look at the uses of EADDRNOTAVAIL it
> is used predominantly in networking code to indicate that attempted
> _network_ address is not available.
EBUSY might be misleading, though. devm_request_and_ioremap() can fail
in both the request_mem_region() and ioremap() calls. Furthermore it'd
be good to settle on a consistent error-code instead of doing it
differently depending on subsystem and/or driver. Currently the various
error codes used are:
EBUSY, EADDRNOTAVAIL, ENXIO, ENOMEM, ENODEV, ENOENT, EINVAL,
EIO, EFAULT, EADDRINUSE
Also if we can settle on one error code we should follow up with a patch
to make it consistent across the tree and also update that kerneldoc
comment. I volunteer to do that if nobody else steps up. I'm also Cc'ing
Wolfram (the original author), maybe he has some thoughts on this.
Thierry
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