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authorAndiry Xu <andiry.xu@amd.com>2010-11-08 17:58:35 +0800
committerGreg Kroah-Hartman <gregkh@suse.de>2010-11-16 13:36:40 -0800
commit3d091a6f703906c5680855ff29bd94d051c8c6d8 (patch)
tree199509dfec473bd44e312862faf441b70eae952c /drivers/usb/host/ehci.h
parent3d965875144b905d71dfb4d291c665c0794222c4 (diff)
downloadblackbird-op-linux-3d091a6f703906c5680855ff29bd94d051c8c6d8.tar.gz
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USB: EHCI: AMD periodic frame list table quirk
On AMD SB700/SB800/Hudson-2/3 platforms, USB EHCI controller may read/write to memory space not allocated to USB controller if there is longer than normal latency on DMA read encountered. In this condition the exposure will be encountered only if the driver has following format of Periodic Frame List link pointer structure: For any idle periodic schedule, the Frame List link pointers that have the T-bit set to 1 intending to terminate the use of frame list link pointer as a physical memory pointer. Idle periodic schedule Frame List Link pointer shoule be in the following format to avoid the issue: Frame list link pointer should be always contains a valid pointer to a inactive QHead with T-bit set to 0. Signed-off-by: Andiry Xu <andiry.xu@amd.com> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/ehci.h')
-rw-r--r--drivers/usb/host/ehci.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index bde823f704e9..ba8eab366b82 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -73,6 +73,7 @@ struct ehci_hcd { /* one per controller */
/* async schedule support */
struct ehci_qh *async;
+ struct ehci_qh *dummy; /* For AMD quirk use */
struct ehci_qh *reclaim;
unsigned scanning : 1;
@@ -131,6 +132,7 @@ struct ehci_hcd { /* one per controller */
unsigned need_io_watchdog:1;
unsigned broken_periodic:1;
unsigned fs_i_thresh:1; /* Intel iso scheduling */
+ unsigned use_dummy_qh:1; /* AMD Frame List table quirk*/
/* required for usb32 quirk */
#define OHCI_CTRL_HCFS (3 << 6)
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