From 9c033e810eef0aff6d4d3bf028aa1e583c074f93 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Thu, 17 May 2007 12:21:19 -0700 Subject: 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 Signed-off-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci.h | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'drivers/usb/host/ehci.h') diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 79ad2af5ef6a..6ef9d775775b 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; -- cgit v1.2.3