Bug#891036: The problem is related to the number of ports created in vhci_hcd.0

From	"wzabolot@elektron.elka.pw.edu.pl" <wzabolot@elektron.elka.pw.edu.pl>
Newsgroups	linux.debian.bugs.dist, linux.debian.kernel
Subject	Bug#891036: The problem is related to the number of ports created in vhci_hcd.0
Date	2018-02-22 23:50 +0100
Message-ID	<vm7QB-2QM-3@gated-at.bofh.it> (permalink)
References	<vlZgm-5tv-5@gated-at.bofh.it> <vm7nA-2DF-23@gated-at.bofh.it> <vlH06-1O8-3@gated-at.bofh.it> <vm7nA-2DF-23@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Cross-posted to 2 groups.

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In fact I don't understand how the vhci_hcd is supposed to work.

The constants are defined as follows:
https://elixir.bootlin.com/linux/v4.15.4/source/drivers/usb/usbip/vhci.h#L75

/* Number of supported ports. Value has an upperbound of USB_MAXCHILDREN */
#ifdef CONFIG_USBIP_VHCI_HC_PORTS
#define VHCI_HC_PORTS CONFIG_USBIP_VHCI_HC_PORTS
#else
#define VHCI_HC_PORTS 8
#endif

/* Each VHCI has 2 hubs (USB2 and USB3), each has VHCI_HC_PORTS ports */
#define VHCI_PORTS    (VHCI_HC_PORTS*2)

#ifdef CONFIG_USBIP_VHCI_NR_HCS
#define VHCI_NR_HCS CONFIG_USBIP_VHCI_NR_HCS
#else
#define VHCI_NR_HCS 1
#endif

#define MAX_STATUS_NAME 16

Then in the line
https://elixir.bootlin.com/linux/v4.15.4/source/drivers/usb/usbip/vhci_hcd.c#L46
we can see:

int vhci_num_controllers = VHCI_NR_HCS;

But, when I have unpacked the sources of the Debian kernel:

("apt source usbip" downloads and unpacks the kernel sources)

In the debian/config/config I can see:

CONFIG_USBIP_CORE=m
CONFIG_USBIP_VHCI_HCD=m
CONFIG_USBIP_VHCI_HC_PORTS=15
CONFIG_USBIP_VHCI_NR_HCS=8
CONFIG_USBIP_HOST=m

So the number of created controllers is equal to 8, and for each
controller there are 30 ports created (2 * 15)

That results in 240 ports, that is above the MAXNPORT number defined in

https://elixir.bootlin.com/linux/v4.15.4/source/tools/usb/usbip/libsrc/vhci_driver.h#L16
#define MAXNPORT 128

To obtain the working configuration it is necessary either to increase
the MAXNPORT to 240 or even to 256 or to decrease the
CONFIG_USBIP_VHCI_NR_HCS to 4


-- 
Wojciech M Zabolotny, PhD
Institute of Electronic Systems
Faculty of Electronics and Information Technology
Warsaw University of Technology

Thread

Bug#891036: libusbip: error: port number exceeds 128 wzab <wzab@ise.pw.edu.pl> - 2018-02-21 19:10 +0100
  Bug#891036: More details - the problem is associated with the vhci-hcd driver. wzab <wzab@ise.pw.edu.pl> - 2018-02-21 20:00 +0100
  Bug#891036: Problem occurs in 4.13 and 4.14, but not in 4.12 "wzabolot@elektron.elka.pw.edu.pl" <wzabolot@elektron.elka.pw.edu.pl> - 2018-02-21 20:30 +0100
  Bug#891036: Problem still persists in kernel 4.15 "wzabolot@elektron.elka.pw.edu.pl" <wzabolot@elektron.elka.pw.edu.pl> - 2018-02-21 21:10 +0100
  Bug#891036: Even after updating "usbip" to usbip_2.0+4.15.4-1_amd64.deb problem remains "wzabolot@elektron.elka.pw.edu.pl" <wzabolot@elektron.elka.pw.edu.pl> - 2018-02-21 21:20 +0100
  Bug#891036: The problem is related to the number of ports created in vhci_hcd.0 Wojtek Zabolotny <W.Zabolotny@elka.pw.edu.pl> - 2018-02-22 14:40 +0100
    Bug#891036: The problem is related to the number of ports created in vhci_hcd.0 "wzabolot@elektron.elka.pw.edu.pl" <wzabolot@elektron.elka.pw.edu.pl> - 2018-02-22 23:20 +0100
      Bug#891036: The problem is related to the number of ports created in vhci_hcd.0 "wzabolot@elektron.elka.pw.edu.pl" <wzabolot@elektron.elka.pw.edu.pl> - 2018-02-22 23:50 +0100
        Bug#891036: Workaround found, the problem is with Debian configuration of kernel "wzabolot@elektron.elka.pw.edu.pl" <wzabolot@elektron.elka.pw.edu.pl> - 2018-02-23 01:10 +0100
        Bug#891036: Proposal - how to make usbip more resistant to misconfiguration "wzabolot@elektron.elka.pw.edu.pl" <wzabolot@elektron.elka.pw.edu.pl> - 2018-02-23 02:10 +0100
  Bug#891036: libusbip: error: port number exceeds 128 Gergely Risko <risko@debian.org> - 2018-05-22 18:20 +0200

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