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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 14:48:20 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-11 14:48:20 -0800
commit414a6750e59b0b687034764c464e9ddecac0f7a6 (patch)
tree18a5ceb11359cd72fcb2d31b5eabf3e35328697f /drivers/usb/core/urb.c
parentc6bd5bcc4983f1a2d2f87a3769bf309482ee8c04 (diff)
parentfb37ef98015f864d22be223a0e0d93547cd1d4ef (diff)
downloadop-kernel-dev-414a6750e59b0b687034764c464e9ddecac0f7a6.zip
op-kernel-dev-414a6750e59b0b687034764c464e9ddecac0f7a6.tar.gz
Merge tag 'usb-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB patches from Greg Kroah-Hartman: "Here's the big set of USB patches for 3.8-rc1. Lots of USB host driver cleanups in here, and a bit of a reorg of the EHCI driver to make it easier for the different EHCI platform drivers to all work together nicer, which was a reduction in overall code. We also deleted some unused firmware files, and got rid of the very old file_storage usb gadget driver that had been broken for a long time. This means we ended up removing way more code than added, always a nice thing to see: 310 files changed, 3028 insertions(+), 10754 deletions(-) Other than that, the usual set of new device ids, driver fixes, gadget driver and controller updates and the like. All of these have been in the linux-next tree for a number of weeks. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" * tag 'usb-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (228 commits) USB: mark uas driver as BROKEN xhci: Add Lynx Point LP to list of Intel switchable hosts uwb: fix uwb_dev_unlock() missed at an error path in uwb_rc_cmd_async() USB: ftdi_sio: Add support for Newport AGILIS motor drivers MAINTAINERS: remove drivers/block/ub.c USB: chipidea: fix use after free bug ezusb: add dependency to USB usb: ftdi_sio: fixup BeagleBone A5+ quirk USB: cp210x: add Virtenio Preon32 device id usb: storage: remove redundant memset() in usb_probe_stor1() USB: option: blacklist network interface on Huawei E173 USB: OHCI: workaround for hardware bug: retired TDs not added to the Done Queue USB: add new zte 3g-dongle's pid to option.c USB: opticon: switch to generic read implementation USB: opticon: refactor reab-urb processing USB: opticon: use usb-serial bulk-in urb USB: opticon: increase bulk-in size USB: opticon: use port as urb context USB: opticon: pass port to get_serial_info USB: opticon: make private data port specific ...
Diffstat (limited to 'drivers/usb/core/urb.c')
-rw-r--r--drivers/usb/core/urb.c29
1 files changed, 25 insertions, 4 deletions
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 9d912bf..e0d9d94 100644
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -214,9 +214,25 @@ EXPORT_SYMBOL_GPL(usb_unanchor_urb);
* urb->interval is modified to reflect the actual transfer period used
* (normally some power of two units). And for isochronous urbs,
* urb->start_frame is modified to reflect when the URB's transfers were
- * scheduled to start. Not all isochronous transfer scheduling policies
- * will work, but most host controller drivers should easily handle ISO
- * queues going from now until 10-200 msec into the future.
+ * scheduled to start.
+ *
+ * Not all isochronous transfer scheduling policies will work, but most
+ * host controller drivers should easily handle ISO queues going from now
+ * until 10-200 msec into the future. Drivers should try to keep at
+ * least one or two msec of data in the queue; many controllers require
+ * that new transfers start at least 1 msec in the future when they are
+ * added. If the driver is unable to keep up and the queue empties out,
+ * the behavior for new submissions is governed by the URB_ISO_ASAP flag.
+ * If the flag is set, or if the queue is idle, then the URB is always
+ * assigned to the first available (and not yet expired) slot in the
+ * endpoint's schedule. If the flag is not set and the queue is active
+ * then the URB is always assigned to the next slot in the schedule
+ * following the end of the endpoint's previous URB, even if that slot is
+ * in the past. When a packet is assigned in this way to a slot that has
+ * already expired, the packet is not transmitted and the corresponding
+ * usb_iso_packet_descriptor's status field will return -EXDEV. If this
+ * would happen to all the packets in the URB, submission fails with a
+ * -EXDEV error code.
*
* For control endpoints, the synchronous usb_control_msg() call is
* often used (in non-interrupt context) instead of this call.
@@ -305,8 +321,13 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
struct usb_host_endpoint *ep;
int is_out;
- if (!urb || urb->hcpriv || !urb->complete)
+ if (!urb || !urb->complete)
return -EINVAL;
+ if (urb->hcpriv) {
+ WARN_ONCE(1, "URB %p submitted while active\n", urb);
+ return -EBUSY;
+ }
+
dev = urb->dev;
if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
return -ENODEV;
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