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authorStuart_Hayes@Dell.com <Stuart_Hayes@Dell.com>2007-05-03 08:58:49 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2007-07-12 16:29:45 -0700
commit196705c9bbc03540429b0f7cf9ee35c2f928a534 (patch)
tree37ddc23737bced60a8defc52f643f362e2744908 /drivers/usb/host/ehci.h
parentec22559e0b7a05283a3413bda5d177e42c950e23 (diff)
USB: EHCI cpufreq fix
EHCI controllers that don't cache enough microframes can get MMF errors when CPU frequency changes occur between the start and completion of split interrupt transactions, due to delays in reading main memory (caused by CPU cache snoop delays). This patch adds a cpufreq notifier to the EHCI driver that will inactivate split interrupt transactions during frequency transitions. It was tested on Intel ICH7 and Serverworks/Broadcom HT1000 EHCI controllers. Signed-off-by: Stuart Hayes <stuart_hayes@dell.com> Signed-off-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.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 46fa57a520d0..a9ba5d28cdc2 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -55,6 +55,12 @@ struct ehci_hcd { /* one per controller */
__u32 hcs_params; /* cached register copy */
spinlock_t lock;
+#ifdef CONFIG_CPU_FREQ
+ struct notifier_block cpufreq_transition;
+ int cpufreq_changing;
+ struct list_head split_intr_qhs;
+#endif
+
/* async schedule support */
struct ehci_qh *async;
struct ehci_qh *reclaim;
@@ -395,6 +401,7 @@ struct ehci_qh {
__le32 hw_next; /* see EHCI 3.6.1 */
__le32 hw_info1; /* see EHCI 3.6.2 */
#define QH_HEAD 0x00008000
+#define QH_INACTIVATE 0x00000080
__le32 hw_info2; /* see EHCI 3.6.2 */
#define QH_SMASK 0x000000ff
#define QH_CMASK 0x0000ff00
@@ -437,6 +444,10 @@ struct ehci_qh {
unsigned short start; /* where polling starts */
#define NO_FRAME ((unsigned short)~0) /* pick new start */
struct usb_device *dev; /* access to TT */
+#ifdef CONFIG_CPU_FREQ
+ struct list_head split_intr_qhs; /* list of split qhs */
+ __le32 was_active; /* active bit before "i" set */
+#endif
} __attribute__ ((aligned (32)));
/*-------------------------------------------------------------------------*/