Messages in this thread | | | Date | Tue, 11 Jun 2019 09:50:40 -0400 (EDT) | From | Alan Stern <> | Subject | Re: [PATCH] USB: add usbfs ioctl to retrieve the connection parameters |
| |
On Mon, 10 Jun 2019, Dmitry Torokhov wrote:
> Recently usfbs gained availability to retrieve device speed, but there > is sill no way to determine the bus number or list of ports the device > is connected to when using usbfs. While this information can be obtained > from sysfs, not all environments allow sysfs access. In a jailed > environment a program might be simply given an opened file descriptor to > usbfs device, and it is really important that all data can be gathered > from said file descriptor. > > This patch introduces a new ioctl, USBDEVFS_CONNINFO_EX, which return > extended connection information for the device, including the bus > number, address, port list and speed. The API allows kernel to extend > amount of data returned by the ioctl and userspace has an option of > adjusting the amount of data it is willing to consume. A new capability, > USBDEVFS_CAP_CONNINFO_EX, is introduced to help userspace in determining > whether the kernel supports this new ioctl. > > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
| |