From mboxrd@z Thu Jan  1 00:00:00 1970
From: oliver.graute@gmail.com (Oliver Graute)
Date: Thu, 19 Jan 2017 09:49:09 +0100
Subject: Downgrade GSM/UMTS module to USB 2.0 Fullspeed
In-Reply-To: <20170118171252.GA12664@kroah.com>
References: <20170118160534.GB11550@graute-opti>
	<20170118171252.GA12664@kroah.com>
Message-ID: <20170119084909.GA17138@graute-opti>
To: kernelnewbies@lists.kernelnewbies.org
List-Id: kernelnewbies.lists.kernelnewbies.org

On 18/01/17, Greg KH wrote:
> On Wed, Jan 18, 2017 at 05:05:34PM +0100, Oliver Graute wrote:
> > Hello list,
> > 
> > i'am using a GSM/UMTS Module on a PCB which is connected with USB 2.0
> > Hi-Speed to my imx6ul CPU. To reduce our Electromagnetic compatibility
> > and to make my hardware colleges happy again I want to downgrade to USB
> > Full Speed.
> > 
> > How can I tell the Linux Kernel to Do so?
> 
> You can't.  It's up to the device to tell the host what "speed" it is
> running at.  See the USB spec for all of the crazy details.
> 
ok thx for this important hint

> I suggest you modify the firmware of your modem to do this, that's the
> only way it is going to work (note, your device needs to be able to
> support full speed, it might not be able to do that.)

I know that the cinterion gsm module support full speed. I have to check their
docs how to force the module into fullspeed.

Best Regards,

Oliver