Re: [RFC PATCH 00/35] Move all PCIBIOS* definitions into arch/x86

[Benjamin Herrenschmidt]

On Wed, 2020-07-15 at 08:47 +0200, Arnd Bergmann wrote:
> drivers/misc/cardreader/rts5261.c:      retval =
> rtsx_pci_write_config_dword(pcr, PCR_SETTING_REG2, lval);
> 
> That last one is interesting because I think this is a case in which
> we
> actually want to check for errors, as the driver seems to use it
> to ensure that accessing extended config space at offset 0x814
> works before relying on the value. Unfortunately the implementation
> seems buggy as it a) keeps using the possibly uninitialized value
> after
> printing a warning and b) returns the PCIBIOS_* value in place of a
> negative errno and then ignores it in the caller.

In cases like this, usually checking against ~0 is sufficient

Cheers,
Ben.