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| author | Alan Stern <stern@rowland.harvard.edu> | 2007-10-10 16:27:07 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-10-12 14:55:34 -0700 |
| commit | 32fe01985aa2cb2562f6fc171e526e279abe10db (patch) | |
| tree | 0c1865a1d3e91ae0839147430480c4099b16a06f /drivers/usb/core/hcd.h | |
| parent | 17f060224fb9f435c6f9306b7b61419d038def13 (diff) | |
| download | blackbird-op-linux-32fe01985aa2cb2562f6fc171e526e279abe10db.tar.gz blackbird-op-linux-32fe01985aa2cb2562f6fc171e526e279abe10db.zip | |
USB: mutual exclusion for EHCI init and port resets
This patch (as999) fixes a problem that sometimes shows up when host
controller driver modules are loaded in the wrong order. If ehci-hcd
happens to initialize an EHCI controller while the companion OHCI or
UHCI controller is in the middle of a port reset, the reset can fail
and the companion may get very confused. The patch adds an
rw-semaphore and uses it to keep EHCI initialization and port resets
mutually exclusive.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: David Miller <davem@davemloft.net>
Cc: Dely L Sy <dely.l.sy@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core/hcd.h')
| -rw-r--r-- | drivers/usb/core/hcd.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h index 1396141274f1..98e24194a4ab 100644 --- a/drivers/usb/core/hcd.h +++ b/drivers/usb/core/hcd.h @@ -19,6 +19,8 @@ #ifdef __KERNEL__ +#include <linux/rwsem.h> + /* This file contains declarations of usbcore internals that are mostly * used or exposed by Host Controller Drivers. */ @@ -470,5 +472,9 @@ static inline void usbmon_urb_complete(struct usb_bus *bus, struct urb *urb, : (in_interrupt () ? "in_interrupt" : "can sleep")) -#endif /* __KERNEL__ */ +/* This rwsem is for use only by the hub driver and ehci-hcd. + * Nobody else should touch it. + */ +extern struct rw_semaphore ehci_cf_port_reset_rwsem; +#endif /* __KERNEL__ */ |
