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When attempting to install RH 7.1 on a Toshiba 1605 CDS laptop installer 
hangs when the CD-ROM does a spin down

Reproducible: Always
Steps to Reproduce:
1.Start installer on the Laptop by booting from CD #1 
2.Can choose text or graphical doesn't matter
2.Wait a few moments for the CD-ROM to Spin down
3.System Locks
	

Actual Results:  Well, the first time it wiped out my laptop hardrive. 
(very bad) Every time after that it leaves my laptop in an unusable 
state.  Upon reboot I get Kernel Panic messages and must reload RH 7.0

Expected Results:  The system should install, and as in the RH 7.0 install 
the CD-ROM will spin-up after I hit the next button.

There is a message I can sometimes catch while the installer is loading 
something like: No IRQ known for interrupt pin A of device 01:00.0. Please 
try using pci=biosirq.

I went to the Kernel archives and did a search on "pci=biosirq" and found 
this message from Linus about a similar topic thought it might be useful.

Regards
Russ

-------
PCI irq routing..
From: Linus Torvalds (torvalds@transmeta.com)
Date: Tue Dec 05 2000 - 18:04:24 EST 

Ok, I now have two confirmations from independent people (Adam Richter and 
Kai Germaschewski) who have completely different hardware, but have the 
same problem: irq routing seems to not work for them. 


In both cases it is because the PCI device config space already has an 
entry for the interrupt, but the interrupt is apparently not actually 
routed on the irq router. 


WHY this happens is unclear, but it could be several reasons: 
 - undocumented "Plug'n'Play OS true behaviour" 
 - BIOS bugs. 'nuff said. 
 - warm-booting from an OS that _does_ set the interrupt routing, 
   and also sets the PCI config space thing 


The problem can be fairly easily fixed by just removing the test for 
whether "pci->dev" has already got set. This, btw, is important for 
another reason too - there is nothing that says that a sleep event 
wouldn't turn off the irq routing, so we _have_ to have some way of 
forcing the interrupt routing to take effect even if we already think we 
have the correct irq. 


However, Martin is certainly also right in claiming that there might be 
bugs the "other" way, and just completely dismissing the irq we already 
are claimed to have would be bad. 


This is my current suggested patch for the problem. 

Adam, Kai, can you verify that it fixes the issues on your systems? 

Anybody else who has had problems with PCI interrupt routing (tends to 
be "new" devices like CardBus, ACPI, USB etc), can you verify that this 
either fixes things or at least doesn't break a setup that had started 
working earlier.. 


Martin, what do you think? We definitely need something like this, but 
maybe we could add a few more sanity-tests? 


                        Linus 



----
--- v2.4.0-test11/linux/arch/i386/kernel/pci-irq.c	Sun Nov 19 
18:44:03 2000
+++ linux/arch/i386/kernel/pci-irq.c	Tue Dec  5 14:38:13 2000
@@ -405,9 +424,12 @@
 	DBG(" -> PIRQ %02x, mask %04x, excl %04x", pirq, mask, pirq_table-
>exclusive_irqs);
 	mask &= pcibios_irq_mask;
 
-	/* Find the best IRQ to assign */
-	newirq = 0;
-	if (assign) {
+	/*
+	 * Find the best IRQ to assign: use the one
+	 * reported by the device if possible.
+	 */
+	newirq = dev->irq;
+	if (!newirq && assign) {
 		for (i = 0; i < 16; i++) {
 			if (!(mask & (1 << i)))
 				continue;
@@ -417,16 +439,22 @@
 				newirq = i;
 			}
 		}
-		DBG(" -> newirq=%d", newirq);
 	}
+	DBG(" -> newirq=%d", newirq);
 
 	/* Try to get current IRQ */
 	if (r->get && (irq = r->get(pirq_router_dev, d, pirq))) {
 		DBG(" -> got IRQ %d\n", irq);
 		msg = "Found";
+		/* We refuse to override the dev->irq information. Give a 
warning! */
+	    	if (dev->irq && dev->irq != irq) {
+	    		printk("IRQ routing conflict in pirq table! 
Try 'pci=autoirq'\n");
+	    		return 0;
+	    	}
 	} else if (newirq && r->set && (dev->class >> 8) != 
PCI_CLASS_DISPLAY_VGA) {
 		DBG(" -> assigning IRQ %d", newirq);
 		if (r->set(pirq_router_dev, d, pirq, newirq)) {
+			eisa_set_level_irq(newirq);
 			DBG(" ... OK\n");
 			msg = "Assigned";
 			irq = newirq;
@@ -556,19 +584,17 @@
 
 void pcibios_enable_irq(struct pci_dev *dev)
 {
-	if (!dev->irq) {
-		u8 pin;
-		pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
-		if (pin && !pcibios_lookup_irq(dev, 1)) {
-			char *msg;
-			if (io_apic_assign_pci_irqs)
-				msg = " Probably buggy MP table.";
-			else if (pci_probe & PCI_BIOS_IRQ_SCAN)
-				msg = "";
-			else
-				msg = " Please try using pci=biosirq.";
-			printk(KERN_WARNING "PCI: No IRQ known for 
interrupt pin %c of device %s.%s\n",
-			       'A' + pin - 1, dev->slot_name, msg);
-		}
+	u8 pin;
+	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin);
+	if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
+		char *msg;
+		if (io_apic_assign_pci_irqs)
+			msg = " Probably buggy MP table.";
+		else if (pci_probe & PCI_BIOS_IRQ_SCAN)
+			msg = "";
+		else
+			msg = " Please try using pci=biosirq.";
+		printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %
c of device %s.%s\n",
+		       'A' + pin - 1, dev->slot_name, msg);
 	}
 }
-