Re: [-mm patch] aic7xxx: check irq validity (was Re: 2.6.18-mm2)

Jeff Garzik
2006-09-30T23:58:36Z

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Frederik Deweerdt wrote:
> On Sat, Sep 30, 2006 at 12:43:24AM +0100, Alan Cox wrote:
>> Ar Gwe, 2006-09-29 am 23:50 +0000, ysgrifennodd Frederik Deweerdt:
>>> Does this patch makes sense in that case? If yes, I'll put up a patch
>>> for the remaining cases in the drivers/scsi/aic7xxx/ directory.
>>> Also, aic7xxx's coding style would put parenthesis around the returned
>>> value, should I follow it?
>> Yes - but perhaps with a warning message so users know why ?
>>
>> As to coding style - kernel style is unbracketed so I wouldnt worry
>> about either.
>>
> Thanks for the advices.
>
> The following patch checks whenever the irq is valid before issuing a
> request_irq() for AIC7XXX and AIC79XX. An error message is displayed to
> let the user know what went wrong.
>
> Regards,
> Frederik
>
> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com>

Actually, rather than adding this check to every driver, I would rather
do something like the attached patch: create a pci_request_irq(), and
pass a struct pci_device to it. Then the driver author doesn't have to
worry about such details.

Jeff

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diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index a544997..9743471 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -809,6 +809,40 @@ err_out:
return -EBUSY;
}

+#ifndef ARCH_VALIDATE_PCI_IRQ
+int pci_valid_irq(struct pci_dev *pdev)
+{
+ if (pdev->irq == 0)
+ return -EINVAL;
+
+ return 0;
+}
+EXPORT_SYMBOL(pci_valid_irq);
+#endif /* ARCH_VALIDATE_PCI_IRQ */
+
+int pci_request_irq(struct pci_dev *pdev,
+ irqreturn_t (*handler)(int, void *, struct pt_regs *),
+ unsigned long flags, const char *name, void *userdata)
+{
+ int rc;
+
+ rc = pci_valid_irq(pdev);
+ if (rc) {
+ dev_printk(KERN_ERR, &pdev->dev, "invalid irq\n");
+ return rc;
+ }
+
+ return request_irq(pdev->irq, handler, flags | IRQF_SHARED,
+ name, userdata);
+}
+EXPORT_SYMBOL(pci_request_irq);
+
+void pci_release_irq(struct pci_dev *pdev, void *userdata)
+{
+ free_irq(pdev->irq, userdata);
+}
+EXPORT_SYMBOL(pci_release_irq);
+
/**
* pci_set_master - enables bus-mastering for device dev
* @dev: the PCI device to enable
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 5c3a417..5e254fc 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -52,6 +52,7 @@ #include <linux/list.h>
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/device.h>
+#include <linux/interrupt.h>

/* File state for mmap()s on /proc/bus/pci/X/Y */
enum pci_mmap_state {
@@ -537,6 +538,12 @@ void pci_release_regions(struct pci_dev
int __must_check pci_request_region(struct pci_dev *, int, const char *);
void pci_release_region(struct pci_dev *, int);

+int __must_check pci_valid_irq(struct pci_dev *pdev);
+int __must_check pci_request_irq(struct pci_dev *pdev,
+ irqreturn_t (*handler)(int, void *, struct pt_regs *),
+ unsigned long flags, const char *name, void *userdata);
+void pci_release_irq(struct pci_dev *pdev, void *userdata);
+
/* drivers/pci/bus.c */
int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
struct resource *res, resource_size_t size,