[PATCH v2 0/4] eUSB2 support

[Sakari Ailus <sakari.ailus@linux.intel.com>]

This series adds support for eUSB2 Double Isochronous IN Bandwidth to the
UVC and xHCI drivers specified in 'USB 2.0 Double Isochronous IN
Bandwidth' ECN. In short, it adds support for new integrated USB2 webcams
that can send twice the data compared to conventional USB2 webcams.

These devices are identified by the device descriptor bcdUSB 0x0220 value.
They have an additional eUSB2 Isochronous Endpoint Companion Descriptor,
and a zero max packet size in regular isoc endpoint descriptor. Support
for parsing that new descriptor was added in commit

c749f058b437 ("USB: core: Add eUSB2 descriptor and parsing in USB core")

This series adds support to UVC, USB core, and xHCI to identify eUSB2
double isoc devices, and allow and set proper max packet, iso frame desc
sizes, bytes per interval, and other values in URBs and xHCI endpoint
contexts needed to support the double data rates for eUSB2 double isoc
devices.

v1 can be found here
<URL:https://lore.kernel.org/linux-usb/20250616093730.2569328-2-mathias.nyman@linux.intel.com/>.

since v1:

- Introduce uvc_endpoint_max_isoc_bpi() to obtain maximum bytes per interval
  value for an endpoint, in a new patch (3rd). This code has been slightly
  reworked from the instance in the UVC driver, adding support for
  SuperSpeedPlus Isochronous Endpoint Companion besides the USB 2.0 Double
  Isochronous In Bandwidth ECN.

- Use uvc_endpoint_max_isoc_bpi() in the UVC driver instead of open-coding
  eUSB2 Double Isochronous In Bandwidth ECNsupport there.

- Use u32 for maximum bpi and related information in the UVC driver -- the
  value could be larger than a 16-bit type can hold.

- Assume max in usb_submit_urb() is a natural number as
  usb_endpoint_maxp() returns only natural numbers (2nd patch).

- Fixed endianness issues in usb_submit_urb() (2nd patch).

- Move the comment on eUSB2 double isoc bw endpoints in
  xhci_get_endpoint_max_burst() to a better location and remove an
  unneeded else clause in the same function (1st patch).

Rai, Amardeep (3):
  xhci: Add host support for eUSB2 double isochronous bandwidth devices
  USB: core: support eUSB2 double bandwidth large isoc URB frames
  USB: Add a function to obtain USB version independent maximum bpi
    value

Tao Q Tao (1):
  media: uvcvideo: eUSB2 double isochronous bandwidth support

 drivers/media/usb/uvc/uvc_driver.c |  4 +-
 drivers/media/usb/uvc/uvc_video.c  | 24 ++----------
 drivers/media/usb/uvc/uvcvideo.h   |  4 +-
 drivers/usb/core/urb.c             | 18 +++++++--
 drivers/usb/host/xhci-caps.h       |  2 +
 drivers/usb/host/xhci-mem.c        | 60 ++++++++++++++++++++++++------
 drivers/usb/host/xhci-ring.c       |  6 +--
 drivers/usb/host/xhci.c            | 16 +++++++-
 drivers/usb/host/xhci.h            | 20 ++++++++++
 include/linux/usb.h                | 22 +++++++++++
 10 files changed, 130 insertions(+), 46 deletions(-)

-- 
2.39.5