kernel/linux.git/include/linux/usbdevice_fs.h, branch v6.19.11

USB: Replace zero-length array with flexible-array member

2020-02-23T18:24:51+00:00

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20200220132017.GA29262@embeddedor Signed-off-by: Greg Kroah-Hartman

USB: add SPDX identifiers to all remaining files in drivers/usb/

2017-11-04T10:48:02+00:00

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/usb/ and include/linux/usb* files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Signed-off-by: Greg Kroah-Hartman Acked-by: Felipe Balbi Acked-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman

UAPI: (Scripted) Disintegrate include/linux

2012-10-13T09:46:48+00:00

Signed-off-by: David Howells Acked-by: Arnd Bergmann Acked-by: Thomas Gleixner Acked-by: Michael Kerrisk Acked-by: Paul E. McKenney Acked-by: Dave Jones

usbfs: Add a new disconnect-and-claim ioctl (v2)

2012-09-10T18:10:37+00:00

Apps which deal with devices which also have a kernel driver, need to do the following: 1) Check which driver is attached, so as to not detach the wrong driver (ie detaching usbfs while another instance of the app is using the device) 2) Detach the kernel driver 3) Claim the interface Where moving from one step to the next for both 1-2 and 2-3 consists of a (small) race window. So currently such apps are racy and people just live with it. This patch adds a new ioctl which makes it possible for apps to do this in a race free manner. For flexibility apps can choose to: 1) Specify the driver to disconnect 2) Specify to disconnect any driver except for the one named by the app 3) Disconnect any driver Note that if there is no driver attached, the ioctl will just act like the regular claim-interface ioctl, this is by design, as returning an error for this condition would open a new bag of race-conditions. Changes in v2: -Fix indentation of if blocks where the condition spans multiple lines Signed-off-by: Hans de Goede Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

usbdevfs: Use scatter-gather lists for large bulk transfers

2012-07-06T17:53:20+00:00

When using urb->transfer_buffer we need to allocate physical contiguous buffers for the entire transfer, which is pretty much guaranteed to fail with large transfers. Currently userspace works around this by breaking large transfers into multiple urbs. For large bulk transfers this leads to all kind of complications. This patch makes it possible for userspace to reliable submit large bulk transfers to scatter-gather capable host controllers in one go, by using a scatterlist to break the transfer up in managable chunks. Signed-off-by: Hans de Goede Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

usbdevfs: Add a USBDEVFS_GET_CAPABILITIES ioctl

2012-07-06T17:53:19+00:00

There are a few (new) usbdevfs capabilities which an application cannot discover in any other way then checking the kernel version. There are 3 problems with this: 1) It is just not very pretty. 2) Given the tendency of enterprise distros to backport stuff it is not reliable. 3) As discussed in length on the mailinglist, USBDEVFS_URB_BULK_CONTINUATION does not work as it should when combined with USBDEVFS_URB_SHORT_NOT_OK (which is its intended use) on devices attached to an XHCI controller. So the availability of these features can be host controller dependent, making depending on them based on the kernel version not a good idea. This patch besides adding the new ioctl also adds flags for the following existing capabilities: USBDEVFS_CAP_ZERO_PACKET, available since 2.6.31 USBDEVFS_CAP_BULK_CONTINUATION, available since 2.6.32, except for XHCI USBDEVFS_CAP_NO_PACKET_SIZE_LIM, available since 3.3 Note that this patch only does not advertise the USBDEVFS_URB_BULK_CONTINUATION cap for XHCI controllers, bulk transfers with this flag set will still be accepted when submitted to XHCI controllers. Returning -EINVAL for them would break existing apps, and in most cases the troublesome scenario wrt USBDEVFS_URB_SHORT_NOT_OK urbs on XHCI controllers will never get hit, so this would break working use cases. The disadvantage of not returning -EINVAL is that cases were it is causing real trouble may go undetected / the cause of the trouble may be unclear, but this is the best we can do. Signed-off-by: Hans de Goede Acked-by: Alan Stern Acked-by: Sarah Sharp Signed-off-by: Greg Kroah-Hartman

usbdevfs: move compat_ioctl handling to devio.c

2009-12-10T21:55:37+00:00

Half the compat_ioctl handling is in devio.c, the other half is in fs/compat_ioctl.c. This moves everything into one place for consistency. As a positive side-effect, push down the BKL into the ioctl methods. Signed-off-by: Arnd Bergmann Acked-by: Greg Kroah-Hartman Cc: Alan Stern Cc: Oliver Neukum Cc: Alon Bar-Lev Cc: David Vrabel Cc: linux-usb@vger.kernel.org

USB: usbfs: add USBDEVFS_URB_BULK_CONTINUATION flag

2009-09-23T13:46:39+00:00

This patch (as1283) adds a new flag, USBDEVFS_URB_BULK_CONTINUATION, to usbfs. It is intended for userspace libraries such as libusb and openusb. When they have to break up a single usbfs bulk transfer into multiple URBs, they will set the flag on all but the first URB of the series. If an error other than an unlink occurs, the kernel will automatically cancel all the following URBs for the same endpoint and refuse to accept new submissions, until an URB is encountered that is not marked as a BULK_CONTINUATION. Such an URB would indicate the start of a new transfer or the presence of an older library, so the kernel returns to normal operation. This enables libraries to delimit bulk transfers correctly, even in the presence of early termination as indicated by short packets. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: add API for userspace drivers to "claim" ports

2009-09-23T13:46:22+00:00

This patch (as1258) implements a feature that users have been asking for: It gives programs the ability to "claim" a port on a hub, via a new usbfs ioctl. A device plugged into a "claimed" port will not be touched by the kernel beyond the immediate necessities of initialization and enumeration. In particular, when a device is plugged into a "claimed" port, the kernel will not select and install a configuration. And when a config is installed by usbfs or sysfs, the kernel will not probe any drivers for any of the interfaces. (However the kernel will fetch various string descriptors during enumeration. One could argue that this isn't really necessary, but the strings are exported in sysfs.) The patch does not guarantee exclusive access to these devices; it is still possible for more than one program to open the device file concurrently. Programs are responsible for coordinating access among themselves. A demonstration program showing how to use the new interface can be found in an attachment to http://marc.info/?l=linux-usb&m=124345857431452&w=2 The patch also makes a small simplification to the hub driver, replacing a bunch of more-or-less useless variants of "out of memory" with a single message. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: remove CVS keywords

2008-07-21T22:15:55+00:00

This patch removes CVS keywords that weren't updated for a long time from comments. Signed-off-by: Adrian Bunk Signed-off-by: Greg Kroah-Hartman