USB: ehci refcounts work on ppc7448
Remove atomic operations on the reference counter for EHCI queue heads.
On various platforms (including ppc7448), atomic operations are unusable
with dma-coherent memory.
Signed-off-by: Steven J. Hill <sjhill1@rockwellcollins.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 79ad2af..6ef9d77 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -457,7 +457,14 @@
struct ehci_qh *reclaim; /* next to reclaim */
struct ehci_hcd *ehci;
- struct kref kref;
+
+ /*
+ * Do NOT use atomic operations for QH refcounting. On some CPUs
+ * (PPC7448 for example), atomic operations cannot be performed on
+ * memory that is cache-inhibited (i.e. being used for DMA).
+ * Spinlocks are used to protect all QH fields.
+ */
+ u32 refcount;
unsigned stamp;
u8 qh_state;