From 57e06c11372eccf5acebdd4664eb025fee76c561 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 16 Jan 2007 11:59:45 -0500 Subject: 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 Cc: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'drivers/usb/host/ehci.h') 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 */ -- cgit v1.2.3