USB: ohci: quirk AMD prefetch for USB 1.1 ISO transfer

The following patch in the driver is required to avoid USB 1.1 device
failures that may occur due to requests from USB OHCI controllers may
be overwritten if the latency for any pending request by the USB
controller is very long (in the range of milliseconds).

Signed-off-by: Libin Yang <libin.yang@amd.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index 222011f6172c..5bf15fed0d9f 100644
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -402,6 +402,7 @@ struct ohci_hcd {
 #define OHCI_QUIRK_FRAME_NO     0x80                    /* no big endian frame_no shift */
 #define OHCI_QUIRK_HUB_POWER    0x100                   /* distrust firmware power/oc setup */
 #define OHCI_QUIRK_AMD_ISO      0x200                   /* ISO transfers*/
+#define OHCI_QUIRK_AMD_PREFETCH 0x400                   /* pre-fetch for ISO transfer */
         // there are also chip quirks/bugs in init logic
 
         struct work_struct      nec_work;       /* Worker for NEC quirk */
@@ -433,6 +434,10 @@ static inline int quirk_amdiso(struct ohci_hcd *ohci)
 {
         return ohci->flags & OHCI_QUIRK_AMD_ISO;
 }
+static inline int quirk_amdprefetch(struct ohci_hcd *ohci)
+{
+        return ohci->flags & OHCI_QUIRK_AMD_PREFETCH;
+}
 #else
 static inline int quirk_nec(struct ohci_hcd *ohci)
 {
@@ -446,6 +451,10 @@ static inline int quirk_amdiso(struct ohci_hcd *ohci)
 {
         return 0;
 }
+static inline int quirk_amdprefetch(struct ohci_hcd *ohci)
+{
+        return 0;
+}
 #endif
 
 /* convert between an hcd pointer and the corresponding ohci_hcd */