Message ID | 20200801112446.149549-1-refactormyself@gmail.com (mailing list archive) |
---|---|
Headers | show |
Series | Drop uses of pci_read_config_*() return value | expand |
On 8/1/20 2:56 PM, Borislav Petkov wrote: > 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? Because the value ~0 has a meaning to some drivers and only drivers have this knowledge. For those cases more checks will be needed to ensure that it is an error that has actually happened. > 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 primary goal is to make pci_config_read*() return void, so that there is *only* one way to check for error i.e. through the obtained value. Again, only the drivers can determine if ~0 is a valid value. This information is not available inside pci_config_read*(). - Saheed