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authorStuart_Hayes@Dell.com <Stuart_Hayes@Dell.com>2007-05-03 17:58:49 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2007-07-13 01:29:45 +0200
commit196705c9bbc03540429b0f7cf9ee35c2f928a534 (patch)
tree37ddc23737bced60a8defc52f643f362e2744908 /drivers/usb/host/ehci-q.c
parentUSB: suspend support for usb serial (diff)
downloadlinux-196705c9bbc03540429b0f7cf9ee35c2f928a534.tar.xz
linux-196705c9bbc03540429b0f7cf9ee35c2f928a534.zip
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-q.c')
-rw-r--r--drivers/usb/host/ehci-q.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index e7fbbd00e7cd..903510beb299 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -311,6 +311,10 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
struct urb *urb;
u32 token = 0;
+ /* ignore QHs that are currently inactive */
+ if (qh->hw_info1 & __constant_cpu_to_le32(QH_INACTIVATE))
+ break;
+
qtd = list_entry (entry, struct ehci_qtd, qtd_list);
urb = qtd->urb;