Re: [ACPI] Re: Fw: Anybody? 2.6.11 (stable and -rc) ACPI breaks USB

[Bjorn Helgaas <bjorn.helgaas@hp.com>]

On Thu, 2005-03-17 at 09:33 +0800, Li Shaohua wrote:
> The comments in previous quirk said it's required only in PIC mode.
...
> I feel we concerned too much. Changing the interrupt line isn't harmful,
> right? Linux actually ignored interrupt line. Maybe just a
> PCI_FIXUP_ENABLE(PCI_VENDOR_ID_VIA, PCI_ANY_ID, quirk_via_irq) is
> sufficient.

I think it's good to limit the scope of the quirk as much as
possible because that makes it easier to do future restructuring,
such as device-specific interrupt routers.

The comment (before quirk_via_acpi(), nowhere near quirk_via_irqpic())
says *on-chip devices* have this unusual behavior when the interrupt
line is written.  That makes sense to me.

Writing the interrupt line on random plug-in Via PCI devices does
not make sense to me, because for that to have any effect, an
upstream bridge would have to be snooping the traffic going through
it.  That doesn't sound plausible to me.

What about this:

===== arch/i386/pci/irq.c 1.55 vs edited =====
--- 1.55/arch/i386/pci/irq.c	2005-02-07 22:39:15 -07:00
+++ edited/arch/i386/pci/irq.c	2005-03-15 10:11:44 -07:00
@@ -1026,7 +1026,6 @@
 static int pirq_enable_irq(struct pci_dev *dev)
 {
 	u8 pin;
-	extern int via_interrupt_line_quirk;
 	struct pci_dev *temp_dev;
 
 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
@@ -1081,10 +1080,6 @@
 		printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device %s.%s\n",
 		       'A' + pin, pci_name(dev), msg);
 	}
-	/* VIA bridges use interrupt line for apic/pci steering across
-	   the V-Link */
-	else if (via_interrupt_line_quirk)
-		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq & 15);
 	return 0;
 }
 
===== drivers/acpi/pci_irq.c 1.37 vs edited =====
--- 1.37/drivers/acpi/pci_irq.c	2005-03-01 09:57:29 -07:00
+++ edited/drivers/acpi/pci_irq.c	2005-03-15 10:10:57 -07:00
@@ -388,7 +388,6 @@
 	u8			pin = 0;
 	int			edge_level = ACPI_LEVEL_SENSITIVE;
 	int			active_high_low = ACPI_ACTIVE_LOW;
-	extern int		via_interrupt_line_quirk;
 
 	ACPI_FUNCTION_TRACE("acpi_pci_irq_enable");
 
@@ -437,9 +436,6 @@
 			return_VALUE(0);
 		}
  	}
-
-	if (via_interrupt_line_quirk)
-		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq & 15);
 
 	dev->irq = acpi_register_gsi(irq, edge_level, active_high_low);
 
===== drivers/pci/quirks.c 1.72 vs edited =====
--- 1.72/drivers/pci/quirks.c	2005-03-10 01:38:25 -07:00
+++ edited/drivers/pci/quirks.c	2005-03-17 10:48:04 -07:00
@@ -683,19 +683,33 @@
 }
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82454NX,	quirk_disable_pxb );
 
-/*
- *	VIA northbridges care about PCI_INTERRUPT_LINE
- */
-int via_interrupt_line_quirk;
+#ifdef CONFIG_ACPI
+#include <linux/acpi.h>
+#endif
 
-static void __devinit quirk_via_bridge(struct pci_dev *pdev)
+static void __devinit quirk_via_irqpic(struct pci_dev *dev)
 {
-	if(pdev->devfn == 0) {
-		printk(KERN_INFO "PCI: Via IRQ fixup\n");
-		via_interrupt_line_quirk = 1;
+	u8 irq, new_irq;
+
+#ifdef CONFIG_ACPI
+	if (acpi_irq_model != ACPI_IRQ_MODEL_PIC)
+		return;
+#endif
+
+	new_irq = dev->irq & 0xf;
+	pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);
+	if (new_irq != irq) {
+		printk(KERN_INFO "PCI: Via PIC IRQ fixup for %s, from %d to %d\n",
+			pci_name(dev), irq, new_irq);
+		udelay(15);
+		pci_write_config_byte(dev, PCI_INTERRUPT_LINE, new_irq);
 	}
 }
-DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_VIA,	PCI_ANY_ID,                     quirk_via_bridge );
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C586_2, quirk_via_irqpic);
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_5, quirk_via_irqpic);
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_6, quirk_via_irqpic);
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_5,   quirk_via_irqpic);
+DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8233_7,   quirk_via_irqpic);
 
 /*
  *	Serverworks CSB5 IDE does not fully support native mode