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authorAlan Stern <stern@rowland.harvard.edu>2013-09-03 17:58:43 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-17 16:49:24 (GMT)
commitc7ccde6eac6d3c4bc6110cc3fd76ef3823bc0831 (patch)
treef5221b8296a245cb9f3e3f84801b1d5d8feb12f9 /include/linux/usb
parent272b98c6455f00884f0350f775c5342358ebb73f (diff)
downloadlinux-fsl-qoriq-c7ccde6eac6d3c4bc6110cc3fd76ef3823bc0831.tar.xz
USB: see if URB comes from a completion handler
Now that URBs can be completed inside tasklets, we need a way of determining whether a completion handler for a given endpoint is currently running. Otherwise it's not possible to maintain the API guarantee about keeping isochronous streams synchronous when an underrun occurs. This patch adds a field and a routine to check whether a completion handler for a periodic endpoint is running. At the moment no analogous routine appears to be necessary for async endpoints, but one can always be added. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/usb')
-rw-r--r--include/linux/usb/hcd.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 75efc45..8c86513 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -73,6 +73,7 @@ struct giveback_urb_bh {
spinlock_t lock;
struct list_head head;
struct tasklet_struct bh;
+ struct usb_host_endpoint *completing_ep;
};
struct usb_hcd {
@@ -378,6 +379,12 @@ static inline int hcd_giveback_urb_in_bh(struct usb_hcd *hcd)
return hcd->driver->flags & HCD_BH;
}
+static inline bool hcd_periodic_completion_in_progress(struct usb_hcd *hcd,
+ struct usb_host_endpoint *ep)
+{
+ return hcd->high_prio_bh.completing_ep == ep;
+}
+
extern int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb);
extern int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
int status);