Re: [PATCH 1/2] usb: dwc3: gadget: Fix full speed mode

[Roger Quadros]

Hi,

On 29/11/16 13:51, Felipe Balbi wrote:
> 
> Hi,
> 
> Roger Quadros <rogerq@xxxxxx> writes:
>> DCFG.DEVSPD == 0x3 is not valid and we need to set
>> DCFG.DEVSPD to 0x1 for full speed mode.
> 
> seems like it has been made invalid somewhere between 1.73a and
> 2.60a. Can you figure it out from Documentation why and when it was made
> invalid? We might need revision checks here.
> 

I'll try to dig out more.
For now from TI DRA7 TRM, 0x3 seems to be FS for serial PHY. (see below)
Do you know if any platform uses that mode?
If we need to support both Full speed modes, how do we specify which
mode we want to set? Some DT parameter?

"0x0: High Speed (HS): 480 Mbit/s - Supported from all
USB controllers
0x1: Full Speed (FS): 12 Mbit/s - Supported from all USB
controllers
0x3: Full Speed (FS): 12 Mbit/s on serial PHY: NOT
SUPPORTED
0x4: Super Speed (SS): 5 Gbit/s - Supported only from
USB1 controller
0x2: Low Speed (LS): 1.5 Mbit/s on serial PHY: NOT
SUPPORTED"

cheers,
-roger