Messages in this thread | | | Date | Mon, 25 Jan 2010 15:52:34 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH 1/4] pci: Update pci_set_vga_state to call arch functions |
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On Mon, 18 Jan 2010 12:34:13 -0600 Mike Travis <travis@sgi.com> wrote:
> Update pci_set_vga_state to call arch dependent functions to enable > Legacy VGA I/O transactions to be redirected to correct target. >
Changelog doesn't explain the reason for doing this, but it looks like that becomes clearer in later patches.
> > +/* Some architectures require additional programming to enable VGA */ > +static arch_set_vga_state_t arch_set_vga_state; > + > +void pci_register_set_vga_state(arch_set_vga_state_t func) > +{ > + arch_set_vga_state = func; /* NULL disables */ > +} > + > +static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode, > + unsigned int command_bits, bool change_bridge) > +{ > + if (arch_set_vga_state) > + return arch_set_vga_state(dev, decode, command_bits, > + change_bridge); > + return 0; > +}
hm, that's not terribly elegant. It's racy too, although it seems unlikely that an arch will call pci_set_vga_state_arch() more than once.
Still, a neater solution might be
int arch_pci_set_vga_state(...) __weak { return 0; }
and then resolve it at linkage time?
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