path: root/drivers/usb/host/ehci.h
diff options
authorAlan Stern <stern@rowland.harvard.edu>2007-01-16 11:59:45 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2007-02-07 15:44:37 -0800
commit57e06c11372eccf5acebdd4664eb025fee76c561 (patch)
treea792559056735005ce7037196509fb151d3c3bc5 /drivers/usb/host/ehci.h
parent625b5c9a0069ef1b61feb3ce599b39f1b04b5666 (diff)
EHCI: force high-speed devices to run at full speed
This patch (as710) adds a sysfs class-device attribute file named "companion" for EHCI controllers. The file contains a list of port numbers that are dedicated to the companion controller; by writing a port number to the file the user can force a high-speed device attached directly to the computer to run at full speed. (As far as I know it is not possible to do this for a device attached to an external hub.) A port is removed from the file by writing the negative of its port number. Several users have asked for this facility and it seems like a useful thing to have. Every now and then one runs across a device which behaves much better at full speed than at high speed. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/ehci.h')
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 3ce7249085d..ec0da0343be 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -74,7 +74,11 @@ struct ehci_hcd { /* one per controller */
/* per root hub port */
unsigned long reset_done [EHCI_MAX_ROOT_PORTS];
- unsigned long bus_suspended;
+ /* bit vectors (one bit per port) */
+ unsigned long bus_suspended; /* which ports were
+ already suspended at the start of a bus suspend */
+ unsigned long companion_ports; /* which ports are
+ dedicated to the companion controller */
/* per-HC memory pools (could be per-bus, but ...) */
struct dma_pool *qh_pool; /* qh per active urb */