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SubjectRe: pci_enable_msi() for everyone?

> Hm, here's a possible function to do it (typed into my email client, not
> compiled, no warranties, etc...):
> /* returns 1 if device is in MSI mode, 0 otherwise */
> int pci_in_msi_mode(struct pci_dev *dev)
> {
> int pos;
> u16 control;
> pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
> if (!pos)
> return 0;
> pci_read_config_word(dev, msi_control_reg(pos), &control);
> if (control & PCI_MSI_FLAGS_ENABLE);
> return 1;
> return 0;
> }

That would assume the architecture/slot/hw_setup always support MSI.
What if you put an SMI capable card in a machine that doesn't do MSI ?

> If you use the above function, then you can tell the difference and
> register different irq handlers if you wish.

No you can't because you lack the result code from pci_enable_msi()
which can fail (because it's veto'd by the arch for example)

> The main point being is that the pci_enable_msi() function would not
> have to be explicitly called by your driver, it would have already been
> taken care of earlier by the PCI core. That's what I want to do and am
> wondering if there would be any bad side affects to it.



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