topic Re: Set usb speed to full (usb 1.1) in i.MX Processors

Set usb speed to full (usb 1.1)

arslan — Tue, 16 Dec 2014 17:59:54 GMT

Hi all,

I am working with imx6q, kernel 3.10.17.

On one usb port, our board acts as a mouse (otg). Up to this Point everything works.

Now our hardware guys want to Limit the Speed to usb 1.1. I tried to set this by setting the the bit PFSC (bit 24) on Register PORTSC, which didn't work of course.

I changed the following file to do this:

Drivers/usb/chipidea/core.c

and inserted the follwoing lines in the function "hw_device_reset(...)"

after the line

while(hw_read(ci, OP_USBCMD, USBCMD_RST))

udelay(10);

hw_write(ci, OP_PORTSC, (1<<24),1); //Added to set to usb1.1

udelay(100); //Added to set to usb1.1

I also tried different udelay-values, writing several times in a Loop...

my device still advertises itself as USB2.0 capable and Hosts select high Speed.

Any ideas where and what to change to force otg as full Speed device?

Re: Set usb speed to full (usb 1.1)

fabio_estevam — Tue, 16 Dec 2014 21:55:02 GMT

This is supported in mainline.

You can try to adapt this patch into your kernel:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/patch/Documentation/devicetree/bindings/usb/ci-hdrc-imx.…

Re: Set usb speed to full (usb 1.1)

jackblather — Wed, 30 Sep 2015 20:57:49 GMT

I just tried this patch in the 3.13 kernel and "lsusb -t" still shows 480M

:smileysad:

Re: Set usb speed to full (usb 1.1)

Raana — Fri, 31 Mar 2017 09:53:37 GMT

Hi Jack,

Even I'm also unable to force the USB otg speed into 'full speed' with L3.14.38.

I have followed that patch too.

Is that solved ??

Please guide me to go further.

Thanks in advance.

Best Regards,

J.P.Raja