[PATCH v2 0/5] usb: host: xhci-plat: omit shared hcd if either of the root hubs has no ports

Heiner Kallweit hkallweit1 at gmail.com
Wed Mar 16 15:08:15 PDT 2022


I have a system with a low-cost Amlogic S905W SoC that supports USB3
but has a USB3 root hub with no ports. This results in an error
message and a hcd that is good for nothing. The USB2 root hub has
ports and works normally.
I think we can do better and omit creating a shared hcd if either of
the root hubs has no ports. This series is based on discussion [0].

The series works as intended for me. What I couldn't test is the case
of the USB2 root hub having no ports.

Follow-up to this series could be applying the xhci-plat extension
to other xhci drivers.

[0] https://www.spinics.net/lists/linux-usb/msg223416.html

v2:
- reordered patches
- create new helper xhci_has_one_roothub() instead of using
  xhci_hcd->needs_shared_hcd (proposed by Mathias)

Heiner Kallweit (5):
  xhci: factor out parts of xhci_gen_setup()
  xhci: prepare for operation w/o shared hcd
  usb: host: xhci-plat: create shared hcd after having added main hcd
  usb: host: xhci-plat: prepare operation w/o shared hcd
  usb: host: xhci-plat: omit shared hcd if either root hub has no ports

 drivers/usb/host/xhci-hub.c  |   3 +-
 drivers/usb/host/xhci-mem.c  |  11 +--
 drivers/usb/host/xhci-plat.c |  46 +++++++----
 drivers/usb/host/xhci.c      | 155 ++++++++++++++++++++---------------
 drivers/usb/host/xhci.h      |  26 ++++++
 5 files changed, 149 insertions(+), 92 deletions(-)

-- 
2.35.1




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