On Wed, 2005-11-16 at 10:06 -0800, Greg KH wrote: > On Wed, Nov 16, 2005 at 02:26:04AM -0500, Adam Belay wrote: > > On Tue, 2005-11-15 at 22:31 -0800, Greg KH wrote: > > > On Tue, Nov 15, 2005 at 10:31:42PM -0500, Adam Belay wrote: > > > > This patch makes some improvements to pci_save_state and > > > > pci_restore_state. Instead of saving and restoring all standard > > > > registers (even read-only ones), it only restores necessary registers. > > > > Also, the command register is handled more carefully. Let me know if > > > > I'm missing anything important. > > > > > > > > > > > > --- a/drivers/pci/pm.c 2005-11-13 20:32:24.000000000 -0500 > > > > +++ b/drivers/pci/pm.c 2005-11-13 20:29:32.000000000 -0500 > > > > @@ -53,10 +53,13 @@ > > > > */ > > > > int pci_save_state(struct pci_dev *dev) > > > > { > > > > - int i; > > > > - /* XXX: 100% dword access ok here? */ > > > > - for (i = 0; i < 16; i++) > > > > - pci_read_config_dword(dev, i * 4,&dev->saved_config_space[i]); > > > > + struct pci_dev_config * conf = &dev->saved_config; > > > > + > > > > + pci_read_config_word(dev, PCI_COMMAND, &conf->command); > > > > + pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &conf->cacheline_size); > > > > + pci_read_config_byte(dev, PCI_LATENCY_TIMER, &conf->latency_timer); > > > > + pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &conf->interrupt_line); > > > > > > Why are we saving and restoring smaller ammounts of config space now? > > > > After looking at the spec, it seems that most of the registers we were > > restoring were read-only and couldn't possibly need to be restored. > > Also, the PCI PM spec suggests that only a subset of the registers > > should be restored. Finally, things like BIST should probably never be > > touched. > > Ok, but be aware that this _might_ cause problems for some cards/drivers > that were relying on the old way... As long as you don't mind me > assigning those bugs to you, I don't have a problem with this :) I'm probably going to regret this, but I'd be happy to take on any PCI PM subsystem bug reports. Unless I forgot a register we need to restore, I'm not expecting this to cause too many problems. A little time in -mm should shake out any issues out rather quickly. Thanks, Adam