[PATCH] pci: fixup parent subordinate busnr (12f44f46) · Commits · 戴 / test

I believe the change that broke things is introduction of pci_fixup_parent_subordinate_busnr(). The patch here does two things: - hunk #1 should fix the problems you've seen when you boot without additional "pci" kernel options; - hunk #2 supposedly fixes boot with "pci=assign-busses" option which otherwise hangs Acer TM81xx machines as reported. Please try this with and without "pci=assign-busses". If it boots, I'd like to see 'lspci -vvx' for both cases. Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

drivers/pci/probe.c

+17 −1

Original line number	Diff line number	Diff line
		@@ -402,6 +402,12 @@ static void pci_enable_crs(struct pci_dev *dev)
		static void __devinit pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max)
		{
		struct pci_bus *parent = child->parent;

		/* Attempts to fix that up are really dangerous unless
		we're going to re-assign all bus numbers. */
		if (!pcibios_assign_all_busses())
		return;

		while (parent->parent && parent->subordinate < max) {
		parent->subordinate = max;
		pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS, max);
		@@ -478,8 +484,18 @@ int __devinit pci_scan_bridge(struct pci_bus bus, struct pci_dev dev, int max
		* We need to assign a number to this bus which we always
		* do in the second pass.
		*/
		if (!pass)
		if (!pass) {
		if (pcibios_assign_all_busses())
		/* Temporarily disable forwarding of the
		configuration cycles on all bridges in
		this bus segment to avoid possible
		conflicts in the second pass between two
		bridges programmed with overlapping
		bus ranges. */
		pci_write_config_dword(dev, PCI_PRIMARY_BUS,
		buses & ~0xffffff);
		return max;
		}

		/* Clear errors */
		pci_write_config_word(dev, PCI_STATUS, 0xffff);

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