Re: USB + PCI - IRQ = kernel bug??

[Jonathan Stanford <jomast@mindspring.com>]

Looks like this patch did the trick guys!
Thanks!

(patch was applied to 2.4.17-pre8)

-Jonathan Stanford


Alan Cox wrote:

>>this problem appears on everything from 2.4.7 (RH7.2 kern)  to the 
>>latest and greatest (2.4.17-pre8) and probably earlier kernels as well....
>>
>>the southbridge/usb controler is the VIA Technologies, Inc. VT82C686b chip as you can see in 
>>
>
>Seems to be a lot of stuff where the pci routing and Linux isnt getting on
>when it comes to VIA and USB. Dunno if its wrong BIOS tables but the
>following previous patch might help you
>
>Let Manfred and co know if it does
>
>Alan
>
>
>>From manfred@colorfullife.com Sun Nov 04 22:07:34 2001
>To: Alan Cox <alan@lxorguk.ukuu.org.uk>
>CC: jgarzik@mandrakesoft.com
>Subject: pci-irq.c
>Status: RO
>
>Hi Alan,
>
>attached is my cleanup of pci-irq.c.
>It works with all my mobos (piix, ali, via) and should fix the vaio
>problem.
>
>The main change is a code cleanup (do not scan first for a good irq,
>and then discard the result and use what's currently installed in
>the irq router, etc) and documentation.
>
>Actual changes:
>* if r->set exists, then always write our idea of the irq number
>into the irq router, even if we use the bios supplied dev->irq number.
>* ignore 'dev2->irq' mismatches - if they exist (e.g. Toms vaio),
>then we must solve them by either using 'dev->irq' or 'dev2->irq'.
>Just looking away means that one device won't work.
>* bounds checking in pirq_via_set. I think I saw pirq=0x58 with my
>ali board, I must check the docu if that can be right.
>
>But I doubt that this solves your via sound problems.
>via sound interrupts are handled with special code in via_quirks,
>and that code is not pirq compatible. Do you have lspci -vxx /
>dump_pirq output?
>
>--
>	Manfred
>
>
>--- 2.4/arch/i386/kernel/pci-irq.c	Sat Nov  3 19:51:08 2001
>+++ build-2.4/arch/i386/kernel/pci-irq.c	Sun Nov  4 22:47:22 2001
>@@ -197,13 +197,24 @@
>  */
> static int pirq_via_get(struct pci_dev *router, struct pci_dev *dev, int pirq)
> {
>-	return read_config_nybble(router, 0x55, pirq);
>+	/* the internal devices (APCI, MC97, AC97, USB port 1 and 2
>+	 * are handled by quirk_via_acpi and quirk_via_irqpic
>+	 */
>+	if (pirq < 6)
>+		return read_config_nybble(router, 0x55, pirq);
>+	return 0;
> }
> 
> static int pirq_via_set(struct pci_dev *router, struct pci_dev *dev, int pirq, int irq)
> {
>-	write_config_nybble(router, 0x55, pirq, irq);
>-	return 1;
>+	/* the internal devices (APCI, MC97, AC97, USB port 1 and 2
>+	 * are handled by quirk_via_acpi and quirk_via_irqpic
>+	 */
>+	if (pirq < 6) {
>+		write_config_nybble(router, 0x55, pirq, irq);
>+		return 1;
>+	}
>+	return 0;
> }
> 
> /*
>@@ -536,8 +547,8 @@
> {
> 	u8 pin;
> 	struct irq_info *info;
>-	int i, pirq, newirq;
>-	int irq = 0;
>+	int i, pirq;
>+	int irq;
> 	u32 mask;
> 	struct irq_router *r = pirq_router;
> 	struct pci_dev *dev2;
>@@ -570,48 +581,65 @@
> 	mask &= pcibios_irq_mask;
> 
> 	/*
>-	 * Find the best IRQ to assign: use the one
>-	 * reported by the device if possible.
>+	 * Find the best IRQ to assign:
>+	 * 1) hardcoded into pirq 0xf?
>+	 * 2) dev->irq.
>+	 * 	There are 2 sources for dev->irq:
>+	 * 	a) stored by the bios into PCI_INTERRUPT_LINE
>+	 * 	b) multiple devices share one pirq, then the loop
>+	 * 	   at the end of this function writes to dev->irq
>+	 * 3) stored by the bios into the irq router
>+	 * 4) only if assign is set: search for a low penalty irq
> 	 */
>-	newirq = dev->irq;
>-	if (!newirq && assign) {
>-		for (i = 0; i < 16; i++) {
>-			if (!(mask & (1 << i)))
>-				continue;
>-			if (pirq_penalty[i] < pirq_penalty[newirq] &&
>-			    !request_irq(i, pcibios_test_irq_handler, SA_SHIRQ, "pci-test", dev)) {
>-				free_irq(i, dev);
>-				newirq = i;
>-			}
>-		}
>-	}
>-	DBG(" -> newirq=%d", newirq);
>-
>-	/* Check if it is hardcoded */
> 	if ((pirq & 0xf0) == 0xf0) {
> 		irq = pirq & 0xf;
> 		DBG(" -> hardcoded IRQ %d\n", irq);
> 		msg = "Hardcoded";
>+	} else if (dev->irq) {
>+		irq = dev->irq;
>+		DBG(" -> preselected IRQ %d\n", irq);
>+		msg = "Preselected";
>+		if (!(mask & (1<<irq)))
>+			printk(KERN_INFO "PCI: pirq table doesn't match preselected IRQ for %s, using preselected irq.\n", dev->slot_name);
> 	} else if (r->get && (irq = r->get(pirq_router_dev, dev, pirq))) {
> 		DBG(" -> got IRQ %d\n", irq);
> 		msg = "Found";
>-	} else if (newirq && r->set && (dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
>-		DBG(" -> assigning IRQ %d", newirq);
>-		if (r->set(pirq_router_dev, dev, pirq, newirq)) {
>-			eisa_set_level_irq(newirq);
>-			DBG(" ... OK\n");
>-			msg = "Assigned";
>-			irq = newirq;
>+		if (!(mask & (1<<irq)))
>+			printk(KERN_INFO "PCI: pirq table doesn't match IRQ router setting for %s, using irq router setting.\n", dev->slot_name);
>+	} else if (assign) {
>+		for (i = 0; i < 16; i++) {
>+			if (!(mask & (1 << i)))
>+				continue;
>+			if (pirq_penalty[i] < pirq_penalty[irq] &&
>+			    !request_irq(i, pcibios_test_irq_handler, SA_SHIRQ, "pci-test", dev)) {
>+				free_irq(i, dev);
>+				irq = i;
>+			}
> 		}
>-	}
>+		DBG(" -> assigning irq=%d\n", irq);
>+		msg = "Assigned";
>+	} else
>+		return 0;
>+	if (!irq)
>+		return 0;
> 
>-	if (!irq) {
>-		DBG(" ... failed\n");
>-		if (newirq && mask == (1 << newirq)) {
>-			msg = "Guessed";
>-			irq = newirq;
>-		} else
>-			return 0;
>+	if ((pirq & 0xf0) != 0xf0 && r->set && (dev->class >> 8) != PCI_CLASS_DISPLAY_VGA) {
>+		/* always rewrite our idea of the interrupt routing back into
>+		 * the irq router
>+		 */
>+		if (r->set(pirq_router_dev, dev, pirq, irq)) {
>+			DBG("Set succeeded\n");
>+			eisa_set_level_irq(irq);
>+		} else {
>+			DBG("Set failed\n");
>+			/* We ignore this error unless there is no way 
>+			 * the irq routing could work without a successful
>+			 * r->set().
>+			 */
>+			if (!strcmp(msg, "Assigned") && mask != (1<<irq)) {
>+				return 0;
>+			}
>+		}
> 	}
> 	printk(KERN_INFO "PCI: %s IRQ %d for device %s\n", msg, irq, dev->slot_name);
> 
>@@ -625,11 +653,13 @@
> 		if (!info)
> 			continue;
> 		if (info->irq[pin].link == pirq) {
>-			/* We refuse to override the dev->irq information. Give a warning! */
>+			/* Give a warning if we have to overwrite dev->irq information.
>+			 * This only happens when multiple devices share one pirq, and
>+			 * the bios claims that it routes them to different irq numbers.
>+			 */
> 		    	if (dev2->irq && dev2->irq != irq) {
> 		    		printk(KERN_INFO "IRQ routing conflict for %s, have irq %d, want irq %d\n",
> 				       dev2->slot_name, dev2->irq, irq);
>-		    		continue;
> 		    	}
> 			dev2->irq = irq;
> 			pirq_penalty[irq]++;
>
>