Originally, the USB core had no support for allocating bandwidth when a
particular configuration or alternate setting for an interface was
selected. Instead, the device driver's URB submission would fail if
there was not enough bandwidth for a periodic endpoint. Drivers could
work around this, by using the scatter-gather list API to guarantee
bandwidth.
This patch adds host controller API to allow the USB core to allocate or
deallocate bandwidth for an endpoint. Endpoints are added to or dropped
from a copy of the current schedule by calling add_endpoint() or
drop_endpoint(), and then the schedule is atomically evaluated with a
call to check_bandwidth(). This allows all the endpoints for a new
configuration or alternate setting to be added at the same time that the
endpoints from the old configuration or alt setting are dropped.
Endpoints must be added to the schedule before any URBs are submitted to
them. The HCD must be allowed to reject a new configuration or alt
setting before the control transfer is sent to the device requesting the
change. It may reject the change because there is not enough bandwidth,
not enough internal resources (such as memory on an embedded host
controller), or perhaps even for security reasons in a virtualized
environment.
If the call to check_bandwidth() fails, the USB core must call
reset_bandwidth(). This causes the schedule to be reverted back to the
state it was in just after the last successful check_bandwidth() call.
If the call succeeds, the host controller driver (and hardware) will have
changed its internal state to match the new configuration or alternate
setting. The USB core can then issue a control transfer to the device to
change the configuration or alt setting. This allows the core to test new
configurations or alternate settings before unbinding drivers bound to
interfaces in the old configuration.
WIP:
The USB core must add endpoints from all interfaces in a configuration
to the schedule, because a driver may claim that interface at any time.
A slight optimization might be to add the endpoints to the schedule once
a driver claims that interface. FIXME
This patch does not cover changing alternate settings, but it does
handle a configuration change or de-configuration. FIXME
The code for managing the schedule is currently HCD specific. A generic
scheduling algorithm could be added for host controllers without
built-in scheduling support. For now, if a host controller does not
define the check_bandwidth() function, the call to
usb_hcd_check_bandwidth() will always succeed.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Modify the USB core to handle the new USB 3.0 speed, "SuperSpeed". This
is 5.0 Gbps (wire speed). There are probably more places that check for
speed that I've missed.
SuperSpeed devices have a 512 byte endpoint 0 max packet size. This shows
up as a bMaxPacketSize0 set to 0x09 (see table 9-8 of the USB 3.0 bus
spec).
xHCI spec says that the xHC can handle intervals up to 2^15 microframes. That
might change when real silicon becomes available.
Add FIXME note for SuperSpeed isochronous endpoints. They can transmit up
to 16 packets in one "burst" before they wait for an acknowledgment of the
packets. They can do up to 3 bursts per microframe (determined by the
mult value in the endpoint companion descriptor). The xHCI driver doesn't
have support for isoc yet, so fix this later.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
transfer_buffer_length and actual_length have become unsigned, therefore some
additional conversion of local variables, function arguments and print
specifications is desired.
A test for a negative urb->transfer_buffer_length became obsolete; instead
we ensure that it does not exceed INT_MAX. Also, urb->actual_length is always
less than urb->transfer_buffer_length.
rh_string() does no longer return -EPIPE in the case of an unsupported ID.
Instead its only caller, rh_call_control() does the check.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
To permit a userspace application to associate with WUSB devices
using numeric association, control transfers to unauthenticated WUSB
devices must be allowed.
This requires that wusbcore correctly sets the device state to
UNAUTHENTICATED, DEFAULT and ADDRESS and that control transfers can be
performed to UNAUTHENTICATED devices.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This extension allows unpoisoning an anchor allowing drivers that
resubmit URBs to reuse an anchor for methods like resume()
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It is enough to protect accesses to reject field of urb
by marking it as atomic_t,also it is the only reason of
existence of usb_reject_lock,so remove the lock to make
code more clean.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The usb_free_urb comment says that the transfer buffer will not be
freed, but this is not the case when URB_FREE_BUFFER is set.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1151) protects usbcore against drivers that try to
unlink an URB after the URB's device or bus have been removed. The
core does not currently check for this, and certain drivers can cause
a crash if they are running while an HCD is unloaded.
Certainly it would be best to fix the guilty drivers. But a little
defensive programming doesn't hurt, especially since it appears that
quite a few drivers need to be fixed.
The patch prevents the problem by grabbing a reference to the device
while an unlink is in progress and using a new spinlock to synchronize
unlinks with device removal. (There's no need to acquire a reference
to the bus as well, since the device structure itself keeps a
reference to the bus.) In addition, the kerneldoc is updated to
indicate that URBs should not be unlinked after the disconnect method
returns.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB should not be having it's own printk macros, so remove err() and
use the system-wide standard of dev_err() wherever possible. In the
few places that will not work out, use a basic printk().
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This extends the anchor API as btusb needs for autosuspend.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
this extends the poisoning concept to anchors. This way poisoning
will work with fire and forget drivers.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
looking at usb_kill_urb() it seems to me that it is unnecessarily lenient.
In the use case of disconnect() you never want to use the URB again
(for the same device) But leaving urb->reject elevated will make it easier
to avoid races between read/write and disconnect.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Irqs must not accidentally be reenabled.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds the ability to trigger asynchronous unlinks of anchored URBs. This
is needed for error handling in the comntext of completion handlers, which
cannot sleep.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Over two years ago, the Linux USB developers stated that they believed
there was no way to create a USB kernel driver that was not under the
GPL. This patch moves the USB apis to enforce that decision.
There are no known closed source USB drivers in the wild, so this patch
should cause no problems.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
URB_FREE_BUFFER needs to be allowed in the sanity checks to use drivers that
use that flag.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as989) makes usbcore flush all outstanding URBs for each
device as the device is suspended. This will be true even when
CONFIG_USB_SUSPEND is not enabled.
In addition, an extra can_submit flag is added to the usb_device
structure. That flag will be turned off whenever a suspend request
has been received for the device, even if the device isn't actually
suspended because CONFIG_USB_SUSPEND isn't set.
It's no longer necessary to check for the device state being equal to
USB_STATE_SUSPENDED during URB submission; that check can be replaced
by a check of the can_submit flag. This also permits us to remove
some questionable references to the deprecated power.power_state field.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that urb->status isn't used, urb->lock doesn't protect anything.
This patch (as980) removes it and replaces it with a private mutex in
the one remaining place it was still used: usb_kill_urb.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as951) cleans up a few loose ends from earlier patches.
Redundant checks for non-NULL urb->dev are removed, as are checks of
urb->dev->bus (which can never be NULL). Conversely, a check for
non-NULL urb->ep is added to the unlink paths.
A homegrown round-down-to-power-of-2 loop is simplified by using the
ilog2 routine. The comparison in usb_urb_dir_in() is made more
transparent.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as947) changes the device initialization and enumeration
code in hub.c; now udev->devnum will be set to 0 while the device is
being accessed at address 0. Until now this wasn't needed because the
address value was passed as part of urb->pipe; without that field the
device address must be stored elsewhere.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as945) adds a bit to urb->transfer_flags for recording the
direction of the URB. The bit is set/cleared automatically in
usb_submit_urb() so drivers don't have to worry about it (although as
a result, it isn't valid until the URB has been submitted). Inline
routines are added for easily checking an URB's direction. They
replace calls to usb_pipein in the DMA-mapping parts of hcd.c.
For non-control endpoints, the direction is determined directly from
the endpoint descriptor. However control endpoints are
bi-directional; for them the direction is determined from the
bRequestType byte and the wLength value in the setup packet.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as943) prepares the way for eliminating urb->pipe by
introducing an endpoint pointer into struct urb. For now urb->ep
is set by usb_submit_urb() from the pipe value; eventually drivers
will set it themselves and we will remove urb->pipe completely.
The patch also adds new inline routines to retrieve an endpoint
descriptor's number and transfer type, essentially as replacements for
usb_pipeendpoint and usb_pipetype.
usb_submit_urb(), usb_hcd_submit_urb(), and usb_hcd_unlink_urb() are
converted to use the new field and new routines. Other parts of
usbcore will be converted in later patches.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as936) updates the kerneldoc for usb_unlink_urb. The
explanation of how endpoint queues are meant to work is now clearer
and in better agreement with reality.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB: Add URB_FREE_BUFFER flag for freeing the transfer buffer
In some cases it is not needed that the driver keeps track of the
transfer buffer of an URB. It can be simply freed along with the
URB itself when the reference count goes down to zero. The new
flag URB_FREE_BUFFER enables this behavior.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as844) makes some trivial whitespace fixes to a few files
in usbcore. Oliver did most of the work and Alan added some tidying up.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as841) removes from usbcore a couple of support routines
meant to help with bandwidth allocation. With the changes to uhci-hcd
in the previous patch, these routines are no longer used anywhere.
Also removed is the CONFIG_USB_BANDWIDTH option; it no longer does
anything and is no longer needed since the HCDs now handle bandwidth
issues correctly.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The patch removes unneeded casts for the following (void *) pointers:
- struct file: private
- struct urb: context
- struct usb_bus: hcpriv
- return value of kmalloc()
The patch also contains some whitespace cleanup in the relevant areas.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
All of the currently-supported USB host controller drivers use the HCD
bus-glue framework. As part of the program for flattening out the glue
layer, this patch (as769) removes the usb_operations structure. All
function calls now go directly to the HCD routines (slightly renamed
to remain within the "usb_" namespace).
The patch also removes usb_alloc_bus(), because it's not useful in the
HCD framework and it wasn't referenced anywhere.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This lets us remove a lot of code in the drivers that were all checking
the same thing. It also found some bugs in a few of the drivers, which
has been fixed up.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Reject URBs to _all_ devices when their host controllers are suspended;
even root hub registers will be unavailable. Also, don't reject urbs
to root hubs in other cases; the only upstream link is through that
controller (on PCI or whatever SOC bus is in use).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/hcd.c | 28 ++++++++++++----------------
drivers/usb/core/urb.c | 3 ++-
2 files changed, 14 insertions(+), 17 deletions(-)
29 July 2005, Cambridge, MA:
This afternoon Alan Stern submitted a patch to remove the URB_ASYNC_UNLINK
flag from the Linux kernel. Mr. Stern explained, "This flag is a relic
from an earlier, less-well-designed system. For over a year it hasn't
been used for anything other than printing warning messages."
An anonymous spokesman for the Linux kernel development community
commented, "This is exactly the sort of thing we see happening all the
time. As the kernel evolves, support for old techniques and old code can
be jettisoned and replaced by newer, better approaches. Proprietary
operating systems do not have the freedom or flexibility to change so
quickly."
Mr. Stern, a staff member at Harvard University's Rowland Institute who
works on Linux only as a hobby, noted that the patch (labelled as548) did
not update two files, keyspan.c and option.c, in the USB drivers' "serial"
subdirectory. "Those files need more extensive changes," he remarked.
"They examine the status field of several URBs at times when they're not
supposed to. That will need to be fixed before the URB_ASYNC_UNLINK flag
is removed."
Greg Kroah-Hartman, the kernel maintainer responsible for overseeing all
of Linux's USB drivers, did not respond to our inquiries or return our
calls. His only comment was "Applied, thanks."
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Greg,
This patch fixes the kmalloc() flags argument type in USB
subsystem; hopefully all of its occurences. The patch was
made against patch-2.6.12-git2 from Jun 20.
Cleanup of flags for kmalloc() in USB subsystem.
Signed-off-by: Olav Kongas <ok@artecdesign.ee>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In response to complaints about excessive latency in the uhci-hcd driver
I'm planning to convert it to a top-half/bottom-half design. It turns out
that to do this, the USB API has to be modified slightly since the driver
will not be able to meet one of the guarantees in the current API. This
patch changes some kerneldoc, specifying the weaker guarantee.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Sarah Sharp