Date: Tue, 19 Apr 2022 22:26:17 +0000 From: "Brian McGovern (bmcgover)" <bmcgover@cisco.com> To: "freebsd-questions@freebsd.org" <freebsd-questions@freebsd.org> Subject: Number of USB devices limited? Message-ID: <BL1PR11MB550957CB5932655D66799676C5F29@BL1PR11MB5509.namprd11.prod.outlook.com>
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Looking at the FreeBSD handbook, Chapter 13, it looks like the expectation =
is that I should be able to attach "the maximum of 126 devices". Unfortuna=
tely, it seems I'm getting in the low 20s (21 FTDI serial cables, USB keybo=
ard, and mouse), after which I start getting the following in the logs:
"Error initializing deviceusb_alloc_device: device init 34 failed (USB_ERR_=
IOERROR, ignored)"
and
"uhub_reattach_port: could not allocate new device".
If I look at /dev/ugen*, there are the ugen devices for 0.1->0.33; so its f=
eeling like there may be limit in the serial port driver for the number of =
/dev/cua* devices, which presently only number cuaU0->cuaU20. So, I'm assum=
ing this may not be a "USB" issue as much as the number of USB serial ports=
(ucom?) that can be connected.
Before I go on a code crawl to figure out how this is failing and if it can=
be scaled up, I'm curious if anyone is aware of a coded limit for the numb=
er of USB serial devices (or USB devices in general) that can be connected =
before running in to this? I'm looking to push upwards to _maybe_ 40 FTDI d=
evices.
-Brian
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<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
Looking at the FreeBSD handbook, Chapter 13, it looks like the expectation =
is that I should be able to attach "the maximum of 126 devices&q=
uot;. Unfortunately, it seems I'm getting in the low 20s (21 FTDI serial ca=
bles, USB keyboard, and mouse), after which I start
getting the following in the logs:</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
<br>
</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
"Error initializing deviceusb_alloc_device: device init 34 failed (USB=
_ERR_IOERROR, ignored)"</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
<br>
</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
and</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
<br>
</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
"uhub_reattach_port: could not allocate new device".</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
<br>
</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
<br>
</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
If I look at /dev/ugen*, there are the ugen devices for 0.1->0.33; so it=
s feeling like there may be limit in the serial port driver for the number =
of /dev/cua* devices, which presently only number cuaU0->cuaU20. So, I'm=
assuming this may not be a "USB" issue
as much as the number of USB serial ports (ucom?) that can be connected.<b=
r>
</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
<br>
</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
Before I go on a code crawl to figure out how this is failing and if it can=
be scaled up, I'm curious if anyone is aware of a coded limit for the numb=
er of USB serial devices (or USB devices in general) that can be connected =
before running in to this? I'm looking
to push upwards to _maybe_ 40 FTDI devices.<br>
</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
<br>
</div>
<div style=3D"font-family: Calibri, Arial, Helvetica, sans-serif; font-size=
: 12pt; color: rgb(0, 0, 0);" class=3D"elementToProof">
-Brian<br>
</div>
</body>
</html>
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