diff options
Diffstat (limited to 'drivers/usb/host/ehci.h')
| -rw-r--r-- | drivers/usb/host/ehci.h | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 79ad2af5ef6..6ef9d775775 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -457,7 +457,14 @@ struct ehci_qh { 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; |