Messages in this thread Patch in this message | | | Date | Wed, 05 Aug 2009 18:10:06 -0400 | From | james puthukattukaran - Sun Microsystems - Burlington United States <> | Subject | [PATCH] ACPI: some issues managing the linked list in acpi_pci_register/unregister_driver |
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I submitted an earlier patch on this to lkml with just a single line initializing the sub_driver variable to NULL. This was insufficient. This patch fixes some link list management issues in adding a new acpi_pci_driver type to the sub_driver list. This is against 2.6.30
Signed-off-by: James Puthukattukaran <james.puthukattukaran@sun.com>
--- linux-2.6.30/drivers/acpi/pci_root.c.orig 2009-08-05 12:56:01.000000000 -0400 +++ linux-2.6.30/drivers/acpi/pci_root.c 2009-08-05 14:28:01.000000000 -0400 @@ -76,7 +76,7 @@ struct acpi_pci_root {
static LIST_HEAD(acpi_pci_roots);
-static struct acpi_pci_driver *sub_driver; +static struct acpi_pci_driver *sub_driver = NULL; static DEFINE_MUTEX(osc_lock);
int acpi_pci_register_driver(struct acpi_pci_driver *driver) @@ -84,10 +84,9 @@ int acpi_pci_register_driver(struct acpi int n = 0; struct list_head *entry;
- struct acpi_pci_driver **pptr = &sub_driver; - while (*pptr) - pptr = &(*pptr)->next; - *pptr = driver; + /* Add to the head of the list */ + driver->next = sub_driver; + sub_driver = driver;
if (!driver->add) return 0; @@ -107,15 +106,21 @@ EXPORT_SYMBOL(acpi_pci_register_driver); void acpi_pci_unregister_driver(struct acpi_pci_driver *driver) { struct list_head *entry; + struct acpi_pci_driver *pptr, *prev;
- struct acpi_pci_driver **pptr = &sub_driver; - while (*pptr) { - if (*pptr == driver) + /* Remove driver from the sub_driver list */ + for (prev = NULL, pptr = sub_driver; pptr; + prev = pptr, pptr=pptr->next) + { + if (pptr == driver) { + if (!prev) + sub_driver = driver->next; + else + prev->next = pptr->next; break; - pptr = &(*pptr)->next; + } } - BUG_ON(!*pptr); - *pptr = (*pptr)->next; + BUG_ON(!pptr);
if (!driver->remove) return; --
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