[Linux-kernel-mentees] [RFC PATCH 00/17] Drop uses of pci_read_config_*() return value

Borislav Petkov bp at alien8.de
Sat Aug 1 12:56:57 UTC 2020

On Sat, Aug 01, 2020 at 01:24:29PM +0200, Saheed O. Bolarinwa wrote:
> The return value of pci_read_config_*() may not indicate a device error.
> However, the value read by these functions is more likely to indicate
> this kind of error. This presents two overlapping ways of reporting
> errors and complicates error checking.

So why isn't the *value check done in the pci_read_config_* functions
instead of touching gazillion callers?

For example, pci_conf{1,2}_read() could check whether the u32 *value it
just read depending on the access method, whether that value is ~0 and
return proper PCIBIOS_ error in that case.

The check you're replicating

	if (val32 == (u32)~0)

everywhere, instead, is just ugly and tests a naked value ~0 which
doesn't mean anything...



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