[PATCH] pci: only call pci_restore_bars at boot (32a36585) · Commits · 戴 / test

Certain (SGI?) ia64 boxes object to having their PCI BARs restored unless absolutely necessary. This patch restricts calling pci_restore_bars from pci_set_power_state unless the current state is PCI_UNKNOWN, the actual (i.e. physical) state of the device is PCI_D3hot, and the device indicates that it will lose its configuration when transitioning to PCI_D0. Signed-off-by:

John W. Linville <linville@tuxdriver.com> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

drivers/pci/pci.c

+12 −4

Original line number	Diff line number	Diff line
		@@ -309,17 +309,25 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state)

		pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);

		/* If we're in D3, force entire word to 0.
		/* If we're (effectively) in D3, force entire word to 0.
		* This doesn't affect PME_Status, disables PME_En, and
		* sets PowerState to 0.
		*/
		if (dev->current_state >= PCI_D3hot) {
		if (!(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
		switch (dev->current_state) {
		case PCI_UNKNOWN: /* Boot-up */
		if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot
		&& !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
		need_restore = 1;
		/* Fall-through: force to D0 */
		case PCI_D3hot:
		case PCI_D3cold:
		case PCI_POWER_ERROR:
		pmcsr = 0;
		} else {
		break;
		default:
		pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
		pmcsr \|= state;
		break;
		}

		/* enter specified state */

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