From: Brian King <brking@us.ibm.com>
I reverted the patch to use a spinlock and added a comment.
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
drivers/pci/access.c | 17 +++++++++++------
1 files changed, 11 insertions(+), 6 deletions(-)
diff -puN drivers/pci/access.c~pci-block-config-access-during-bist-resend drivers/pci/access.c
--- 25/drivers/pci/access.c~pci-block-config-access-during-bist-resend Fri Sep 9 16:50:39 2005
+++ 25-akpm/drivers/pci/access.c Fri Sep 9 16:50:39 2005
@@ -122,11 +122,14 @@ PCI_USER_WRITE_CONFIG(dword, u32)
**/
void pci_block_user_cfg_access(struct pci_dev *dev)
{
+ unsigned long flags;
+
pci_save_state(dev);
+
+ /* spinlock to synchronize with anyone reading config space now */
+ spin_lock_irqsave(&pci_lock, flags);
dev->block_ucfg_access = 1;
- mb();
- while (spin_is_locked(&pci_lock))
- cpu_relax();
+ spin_unlock_irqrestore(&pci_lock, flags);
}
EXPORT_SYMBOL_GPL(pci_block_user_cfg_access);
@@ -138,9 +141,11 @@ EXPORT_SYMBOL_GPL(pci_block_user_cfg_acc
**/
void pci_unblock_user_cfg_access(struct pci_dev *dev)
{
+ unsigned long flags;
+
+ /* spinlock to synchronize with anyone reading saved config space */
+ spin_lock_irqsave(&pci_lock, flags);
dev->block_ucfg_access = 0;
- mb();
- while (spin_is_locked(&pci_lock))
- cpu_relax();
+ spin_unlock_irqrestore(&pci_lock, flags);
}
EXPORT_SYMBOL_GPL(pci_unblock_user_cfg_access);
_