AnsweredAssumed Answered

Set usb speed to full (usb 1.1)

Question asked by hasan arslan on Dec 16, 2014
Latest reply on Mar 31, 2017 by Raana

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?

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