Re: USB CDC performance test

Greg KH
2022-03-04T15:01:19Z

On Fri, Mar 04, 2022 at 08:06:55PM +0530, Mithran B wrote:
> On Fri, 4 Mar 2022 at 19:48, Greg KH <greg@kroah.com> wrote:
>
> > On Fri, Mar 04, 2022 at 04:27:50PM +0530, Mithran B wrote:
> > > Hello,
> > >
> > > In Host and Gadget systems, enabled the USB CDC drivers.
> > > Then nodes are created as /dev/ttyAcm0 and /dev/ttyGs0.
> > > Then opened the nodes and write and read back the data.
> > > It is working.
> > >
> > > I want to test the performance of this interface and drivers.
> > > Do we have any utility for this?
> > > How to do the performance test?
> >
> > What exactly do you want to measure? Determine that first before trying
> > to find a test for that. Without knowing what you want to measure, it's
> > hard to tell you how to measure it :)
> >
> > good luck!
> >
> > greg k-h
> >
>
> Thank you.
> I want to send the data at the rate of 5mbps from Host device to target
> device using USB CDC - ACM.
> In termios functions, how to configure this 5mbps as baud rate and USB
> payload size, i.e. packet
> size to be in 2K bytes.

There is no "baud rate" for usb cdc devices, really, as you have tried
this already, right?

Just send the data as fast as you can, with the largest chunks of data
that you have (do not send it byte by byte to the kernel), and you
should be fine.

Are you sure that your device can handle that type of data rate? That's
almost always the limiting factor.

good luck!

greg k-h