| Message ID | 1307307517-28365-1-git-send-email-jslaby@suse.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c index 4a29763..feac720 100644 --- a/drivers/acpi/pci_link.c +++ b/drivers/acpi/pci_link.c @@ -557,7 +557,7 @@ static int acpi_pci_link_allocate(struct acpi_pci_link *link) * the use of IRQs 9, 10, 11, and >15. */ for (i = (link->irq.possible_count - 1); i >= 0; i--) { - if (acpi_irq_penalty[irq] > + if (acpi_irq_penalty[irq] >= acpi_irq_penalty[link->irq.possible[i]]) irq = link->irq.possible[i]; }
On IBM Bartolo machines, the serial board enumerated as 00:09.0 is defunct (if uses interrupts). The board has probably incorrectly set IRQ routing in BIOS. DSDT says that this slot (with function 0, i.e. pin A) is routed to \_SB_.PCI0.PIB_.LNKB. But it doesn't look like that. If a quirk is added to override this to LNKC, it works OK. What's interesting is that Windows (with ACPI enabled) work with this system without problems. So it does with ACPI routing disabled in Linux. By investigating further we found out (there are two boards with two ports each): * acpi routing enabled (no kernel parameter) => ports 4+5 defunct. ports 4+5+6+7 are all on irq 11 * acpi routing disabled (acpi=noirq) => all ports working, 4+5 on irq 10, 6+7 on irq 11 * with the quirk and acpi routing enabled => all ports working, ports 4+5 on irq 10, 6+7 on irq 11 * with this patch and acpi routing enabled => all ports working, ports 4+5 on irq 10, 6+7 on irq 11 * in windows (ACPI enabled) => 4+5+6+7 are all on irq 9 and the ports are all working. As Windows seem to use the lowest possible IRQ, let's do the same thing. However they perhaps enumerate the buses in a different order so they end up with different IRQs. References: https://bugzilla.kernel.org/show_bug.cgi?id=18092 References: https://bugzilla.novell.com/show_bug.cgi?id=595683 References: https://lkml.org/lkml/2011/4/12/323 Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Len Brown <lenb@kernel.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Matthew Garrett <mjg59@srcf.ucam.org> --- drivers/acpi/pci_link.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)