On Tue, 25 Jan 2022 09:18:59 -0600, Terry Bowman wrote:
> On 1/25/22 7:45 AM, Jean Delvare wrote:
> > On Tue, 18 Jan 2022 14:22:32 -0600, Terry Bowman wrote:
> >> +static int __sp5100_tco_prepare_base(struct sp5100_tco *tco,
> >> + u32 mmio_addr,
> >> + const char *dev_name)
> >> +{
> >> + struct device *dev = tco->wdd.parent;
> >> + int ret = 0;
> >> +
> >> + if (!mmio_addr)
> >> + return -ENOMEM;
> >
> > Can this actually happen? If it does, is -ENOMEM really the best error
> > value?
>
> This can happen if mmio_addr is not assigned in sp5100_tco_setupdevice_mmio()
> before calling sp5100_tco_prepare_base() and __sp5100_tco_prepare_base().
Ah yes, I can see it now.
> I can move the NULL check out of __sp5100_tco_prepare_base() and into
> sp5100_tco_prepare_base() before calling __sp5100_tco_prepare_base().
> As you describe below.
>
> The ENOMEM return value should be interpreted as the mmio_addr is not
> available. EBUSY does not describe the failure correctly because EBUSY
> implies the resource is present and normally available but not available
> at this time. Do you have a return value preference ?
Well, if one mmio_addr isn't set, you shouldn't call
__sp5100_tco_prepare_base() for it so there's no error to return. If
neither mmio_addr is set then the hardware is simply not configured to
be used, so that would be a -NODEV returned by
sp5100_tco_prepare_base() I suppose?
BTW...
> >> (...)
> >> + if (ret)
> >> + dev_err(dev, "Failed to reserve-map MMIO (%X) and alternate MMIO (%X) regions. ret=%X",
> >> + mmio_addr, alt_mmio_addr, ret);
... I think that should be a "or" rather than "and", and singular
"region", in this error message? I mean, the plan was never to
reserve-map both of them, if I understand correctly.
--
Jean Delvare
SUSE L3 Support
