From 5cd130c7a0ec6bdd04d837be9e2d7ab6c2e1dfd0 Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Fri, 22 Aug 2008 09:47:17 -0600 Subject: [PATCH] PNPACPI: ignore the producer/consumer bit for extended IRQ descriptors The Extended Interrupt descriptor has a producer/consumer bit, but it's not clear what that would mean, and existing BIOSes use the bit inconsistently. This patch makes Linux PNPACPI ignore the bit. The ACPI spec contains examples of PCI Interrupt Link devices marked as ResourceProducers, but many BIOSes mark them as ResourceConsumers. I also checked with a Windows contact, who said: Windows uses only "resource consumer" when dealing with interrupts. There's no useful way of looking at a resource producer of interrupts. ... NT-based Windows largely infers the producer/consumer stuff from the device type and ignores the bits in the namespace. This was necessary because Windows 98 ignored them and early namespaces contained random junk. The reason I want to change this is because if PNPACPI devices exclude ResourceProducer IRQ resources, we can't write PNP drivers for those devices. For example, on machines such as the the HP rx7620, rx7640, rx8620, rx8640, and Superdome, HPET interrupts are ResourceProducers. The HPET driver currently has to use acpi_bus_register_driver() and do its own _CRS parsing, even though it requires absolutely no ACPI-specific functionality. It would be better if the HPET driver were a PNP driver and took advantage of the _CRS parsing built into PNPACPI. This producer/consumer check was originally added here: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=4360309b5baa48bb6139c5cb28f2df2f0bf21cef to fix this bug: http://bugzilla.kernel.org/show_bug.cgi?id=6292 However, the bug was related only to memory and I/O port resources, where the distinction is sensible and important to Linux. Given that the distinction is muddled for IRQ resources, I think it was a mistake to add the check there. Signed-off-by: Bjorn Helgaas Signed-off-by: Andi Kleen --- drivers/pnp/pnpacpi/rsparser.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c index d7e9f2152df09..95015cbfd33f4 100644 --- a/drivers/pnp/pnpacpi/rsparser.c +++ b/drivers/pnp/pnpacpi/rsparser.c @@ -405,8 +405,6 @@ static acpi_status pnpacpi_allocated_resource(struct acpi_resource *res, case ACPI_RESOURCE_TYPE_EXTENDED_IRQ: extended_irq = &res->data.extended_irq; - if (extended_irq->producer_consumer == ACPI_PRODUCER) - return AE_OK; if (extended_irq->interrupt_count == 0) pnp_add_irq_resource(dev, 0, IORESOURCE_DISABLED); -- 2.39.5