* [PATCH 2.4.19-bk8] arch/i386/kernel/pci-irq.c: Wrong message output
@ 2005-02-08 4:37 Mark F. Haigh
2005-02-08 5:55 ` Mark F. Haigh
0 siblings, 1 reply; 3+ messages in thread
From: Mark F. Haigh @ 2005-02-08 4:37 UTC (permalink / raw)
To: marcelo.tosatti, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 902 bytes --]
I'd submitted a patch earlier for this file, fixing a warning. When I
looked at it further, I noticed it can output an incorrect warning
message under certain circumstances. I've confirmed that this can and
does happen in the wild:
PCI: Enabling device 0000:00:0a.0 (0000 -> 0001)
PCI: No IRQ known for interrupt pin @ of device 0000:00:0a.0. Probably
buggy MP table.
It should read "No IRQ known for interrupt pin A", but the 'pin'
variable has already been decremented (from 1 to 0), so the line:
printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device
%s.%s\n", 'A' + pin - 1, dev->slot_name, msg);
causes "pin @" to be output, because 'A' + 0 - 1 == '@'.
This patch also fixes the original warning:
pci-irq.c: In function `pcibios_enable_irq':
pci-irq.c:1128: warning: 'msg' might be used uninitialized in this function
Thanks,
Mark Haigh
Mark.Haigh@spirentcom.com
[-- Attachment #2: pci-irq-patch --]
[-- Type: text/plain, Size: 3191 bytes --]
--- arch/i386/kernel/pci-irq.c.orig 2005-02-07 19:55:23.852531544 -0800
+++ arch/i386/kernel/pci-irq.c 2005-02-07 20:13:38.835068896 -0800
@@ -1127,6 +1127,8 @@
if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
char *msg;
+ pin--; /* interrupt pins are numbered starting from 1 */
+
/* With IDE legacy devices the IRQ lookup failure is not a problem.. */
if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE && !(dev->class & 0x5))
return;
@@ -1134,42 +1136,39 @@
if (io_apic_assign_pci_irqs) {
int irq;
- if (pin) {
- pin--; /* interrupt pins are numbered starting from 1 */
- irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
- /*
- * Busses behind bridges are typically not listed in the MP-table.
- * In this case we have to look up the IRQ based on the parent bus,
- * parent slot, and pin number. The SMP code detects such bridged
- * busses itself so we should get into this branch reliably.
- */
- temp_dev = dev;
- while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
- struct pci_dev * bridge = dev->bus->self;
+ irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
+ /*
+ * Busses behind bridges are typically not listed in the MP-table.
+ * In this case we have to look up the IRQ based on the parent bus,
+ * parent slot, and pin number. The SMP code detects such bridged
+ * busses itself so we should get into this branch reliably.
+ */
+ temp_dev = dev;
+ while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
+ struct pci_dev * bridge = dev->bus->self;
- pin = (pin + PCI_SLOT(dev->devfn)) % 4;
- irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
- PCI_SLOT(bridge->devfn), pin);
- if (irq >= 0)
- printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n",
- bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
- dev = bridge;
- }
- dev = temp_dev;
- if (irq >= 0) {
- printk(KERN_INFO "PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
- dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
- dev->irq = irq;
- return;
- } else
- msg = " Probably buggy MP table.";
+ pin = (pin + PCI_SLOT(dev->devfn)) % 4;
+ irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
+ PCI_SLOT(bridge->devfn), pin);
+ if (irq >= 0)
+ printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n",
+ bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
+ dev = bridge;
}
+ dev = temp_dev;
+ if (irq >= 0) {
+ printk(KERN_INFO "PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
+ dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
+ dev->irq = irq;
+ return;
+ } else
+ 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);
+ 'A' + pin, dev->slot_name, msg);
}
/* VIA bridges use interrupt line for apic/pci steering across
the V-Link */
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH 2.4.19-bk8] arch/i386/kernel/pci-irq.c: Wrong message output
2005-02-08 4:37 [PATCH 2.4.19-bk8] arch/i386/kernel/pci-irq.c: Wrong message output Mark F. Haigh
@ 2005-02-08 5:55 ` Mark F. Haigh
2005-02-08 6:17 ` Mark F. Haigh
0 siblings, 1 reply; 3+ messages in thread
From: Mark F. Haigh @ 2005-02-08 5:55 UTC (permalink / raw)
To: marcelo.tosatti; +Cc: Mark F. Haigh, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 302 bytes --]
Mark F. Haigh wrote:
>
> --- arch/i386/kernel/pci-irq.c.orig 2005-02-07 19:55:23.852531544 -0800
> +++ arch/i386/kernel/pci-irq.c 2005-02-07 20:13:38.835068896 -0800
Apologies. Patch now -p1-able.
Mark F. Haigh
Mark.Haigh@spirentcom.com
Signed-off-by: Mark F. Haigh <Mark.Haigh@spirentcom.com>
[-- Attachment #2: pci-irq-patch2 --]
[-- Type: text/plain, Size: 3225 bytes --]
--- linux-2.4.29-bk8/arch/i386/kernel/pci-irq.c.orig 2005-02-07 19:55:23.000000000 -0800
+++ linux-2.4.29-bk8/arch/i386/kernel/pci-irq.c 2005-02-07 20:13:38.000000000 -0800
@@ -1127,6 +1127,8 @@
if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
char *msg;
+ pin--; /* interrupt pins are numbered starting from 1 */
+
/* With IDE legacy devices the IRQ lookup failure is not a problem.. */
if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE && !(dev->class & 0x5))
return;
@@ -1134,42 +1136,39 @@
if (io_apic_assign_pci_irqs) {
int irq;
- if (pin) {
- pin--; /* interrupt pins are numbered starting from 1 */
- irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
- /*
- * Busses behind bridges are typically not listed in the MP-table.
- * In this case we have to look up the IRQ based on the parent bus,
- * parent slot, and pin number. The SMP code detects such bridged
- * busses itself so we should get into this branch reliably.
- */
- temp_dev = dev;
- while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
- struct pci_dev * bridge = dev->bus->self;
+ irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
+ /*
+ * Busses behind bridges are typically not listed in the MP-table.
+ * In this case we have to look up the IRQ based on the parent bus,
+ * parent slot, and pin number. The SMP code detects such bridged
+ * busses itself so we should get into this branch reliably.
+ */
+ temp_dev = dev;
+ while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
+ struct pci_dev * bridge = dev->bus->self;
- pin = (pin + PCI_SLOT(dev->devfn)) % 4;
- irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
- PCI_SLOT(bridge->devfn), pin);
- if (irq >= 0)
- printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n",
- bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
- dev = bridge;
- }
- dev = temp_dev;
- if (irq >= 0) {
- printk(KERN_INFO "PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
- dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
- dev->irq = irq;
- return;
- } else
- msg = " Probably buggy MP table.";
+ pin = (pin + PCI_SLOT(dev->devfn)) % 4;
+ irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
+ PCI_SLOT(bridge->devfn), pin);
+ if (irq >= 0)
+ printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n",
+ bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
+ dev = bridge;
}
+ dev = temp_dev;
+ if (irq >= 0) {
+ printk(KERN_INFO "PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
+ dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
+ dev->irq = irq;
+ return;
+ } else
+ 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);
+ 'A' + pin, dev->slot_name, msg);
}
/* VIA bridges use interrupt line for apic/pci steering across
the V-Link */
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH 2.4.19-bk8] arch/i386/kernel/pci-irq.c: Wrong message output
2005-02-08 5:55 ` Mark F. Haigh
@ 2005-02-08 6:17 ` Mark F. Haigh
0 siblings, 0 replies; 3+ messages in thread
From: Mark F. Haigh @ 2005-02-08 6:17 UTC (permalink / raw)
To: marcelo.tosatti; +Cc: Mark F. Haigh, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 1072 bytes --]
Mark F. Haigh wrote:
>
> Apologies. Patch now -p1-able.
>
[Apologies yet again, now includes description]
I'd submitted a patch earlier for this file, fixing a warning. When I
looked at it further, I noticed it can output an incorrect warning
message under certain circumstances. I've confirmed that this can and
does happen in the wild:
PCI: Enabling device 0000:00:0a.0 (0000 -> 0001)
PCI: No IRQ known for interrupt pin @ of device 0000:00:0a.0. Probably
buggy MP table.
It should read "No IRQ known for interrupt pin A", but the 'pin'
variable has already been decremented (from 1 to 0), so the line:
printk(KERN_WARNING "PCI: No IRQ known for interrupt pin %c of device
%s.%s\n", 'A' + pin - 1, dev->slot_name, msg);
causes "pin @" to be output, because 'A' + 0 - 1 == '@'.
This patch also fixes the original warning:
pci-irq.c: In function `pcibios_enable_irq':
pci-irq.c:1128: warning: 'msg' might be used uninitialized in this function
Thanks,
Mark Haigh
Mark.Haigh@spirentcom.com
Signed-off-by: Mark F. Haigh <Mark.Haigh@spirentcom.com>
[-- Attachment #2: pci-irq-patch2 --]
[-- Type: text/plain, Size: 3225 bytes --]
--- linux-2.4.29-bk8/arch/i386/kernel/pci-irq.c.orig 2005-02-07 19:55:23.000000000 -0800
+++ linux-2.4.29-bk8/arch/i386/kernel/pci-irq.c 2005-02-07 20:13:38.000000000 -0800
@@ -1127,6 +1127,8 @@
if (pin && !pcibios_lookup_irq(dev, 1) && !dev->irq) {
char *msg;
+ pin--; /* interrupt pins are numbered starting from 1 */
+
/* With IDE legacy devices the IRQ lookup failure is not a problem.. */
if (dev->class >> 8 == PCI_CLASS_STORAGE_IDE && !(dev->class & 0x5))
return;
@@ -1134,42 +1136,39 @@
if (io_apic_assign_pci_irqs) {
int irq;
- if (pin) {
- pin--; /* interrupt pins are numbered starting from 1 */
- irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
- /*
- * Busses behind bridges are typically not listed in the MP-table.
- * In this case we have to look up the IRQ based on the parent bus,
- * parent slot, and pin number. The SMP code detects such bridged
- * busses itself so we should get into this branch reliably.
- */
- temp_dev = dev;
- while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
- struct pci_dev * bridge = dev->bus->self;
+ irq = IO_APIC_get_PCI_irq_vector(dev->bus->number, PCI_SLOT(dev->devfn), pin);
+ /*
+ * Busses behind bridges are typically not listed in the MP-table.
+ * In this case we have to look up the IRQ based on the parent bus,
+ * parent slot, and pin number. The SMP code detects such bridged
+ * busses itself so we should get into this branch reliably.
+ */
+ temp_dev = dev;
+ while (irq < 0 && dev->bus->parent) { /* go back to the bridge */
+ struct pci_dev * bridge = dev->bus->self;
- pin = (pin + PCI_SLOT(dev->devfn)) % 4;
- irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
- PCI_SLOT(bridge->devfn), pin);
- if (irq >= 0)
- printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n",
- bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
- dev = bridge;
- }
- dev = temp_dev;
- if (irq >= 0) {
- printk(KERN_INFO "PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
- dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
- dev->irq = irq;
- return;
- } else
- msg = " Probably buggy MP table.";
+ pin = (pin + PCI_SLOT(dev->devfn)) % 4;
+ irq = IO_APIC_get_PCI_irq_vector(bridge->bus->number,
+ PCI_SLOT(bridge->devfn), pin);
+ if (irq >= 0)
+ printk(KERN_WARNING "PCI: using PPB(B%d,I%d,P%d) to get irq %d\n",
+ bridge->bus->number, PCI_SLOT(bridge->devfn), pin, irq);
+ dev = bridge;
}
+ dev = temp_dev;
+ if (irq >= 0) {
+ printk(KERN_INFO "PCI->APIC IRQ transform: (B%d,I%d,P%d) -> %d\n",
+ dev->bus->number, PCI_SLOT(dev->devfn), pin, irq);
+ dev->irq = irq;
+ return;
+ } else
+ 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);
+ 'A' + pin, dev->slot_name, msg);
}
/* VIA bridges use interrupt line for apic/pci steering across
the V-Link */
^ permalink raw reply [flat|nested] 3+ messages in thread
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2005-02-08 5:55 ` Mark F. Haigh
2005-02-08 6:17 ` Mark F. Haigh
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