From 7cbe5dca399a50ce8aa74314b1d276e2fb904e1b Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 29 Jun 2009 10:56:54 -0400 Subject: USB: add API for userspace drivers to "claim" ports 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 --- include/linux/usbdevice_fs.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/usbdevice_fs.h') diff --git a/include/linux/usbdevice_fs.h b/include/linux/usbdevice_fs.h index 0044d9b4cb8..00ceebeb9e5 100644 --- a/include/linux/usbdevice_fs.h +++ b/include/linux/usbdevice_fs.h @@ -175,4 +175,6 @@ struct usbdevfs_ioctl32 { #define USBDEVFS_CLEAR_HALT _IOR('U', 21, unsigned int) #define USBDEVFS_DISCONNECT _IO('U', 22) #define USBDEVFS_CONNECT _IO('U', 23) +#define USBDEVFS_CLAIM_PORT _IOR('U', 24, unsigned int) +#define USBDEVFS_RELEASE_PORT _IOR('U', 25, unsigned int) #endif /* _LINUX_USBDEVICE_FS_H */ -- cgit v1.2.3 From 01c6460f968d7b57fc6f98adb587952628c6e099 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 1 Sep 2009 11:09:56 -0400 Subject: USB: usbfs: add USBDEVFS_URB_BULK_CONTINUATION flag 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 --- include/linux/usbdevice_fs.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/usbdevice_fs.h') diff --git a/include/linux/usbdevice_fs.h b/include/linux/usbdevice_fs.h index 00ceebeb9e5..b2a7d8ba6ee 100644 --- a/include/linux/usbdevice_fs.h +++ b/include/linux/usbdevice_fs.h @@ -77,6 +77,7 @@ struct usbdevfs_connectinfo { #define USBDEVFS_URB_SHORT_NOT_OK 0x01 #define USBDEVFS_URB_ISO_ASAP 0x02 +#define USBDEVFS_URB_BULK_CONTINUATION 0x04 #define USBDEVFS_URB_NO_FSBR 0x20 #define USBDEVFS_URB_ZERO_PACKET 0x40 #define USBDEVFS_URB_NO_INTERRUPT 0x80 -- cgit v1.2.3