[ELDK] Linux DWC OTG Driver - Host mode

[Mark Malopy]

Wolfgang,

Just a clarification, I am on a platform that is based off on Kilauea - not the Kilauea platform itself. As such, I need to build and modify the Kernel and device tree for our specific hardware features and cannot use the link you provided.

However, upgrading to kernel based on 2.6.32 source is proving somewhat difficult as it locks up while loading the Device Tree and bootup - normally, I would debug this... but looking at the DWC-OTG Driver source code between 2.6.31 and 2.6.32, there are no changes to the Synopsis OTG drivers (the last changes to this code was back in September of 09). It would be frustrating to spend the time resolving kernel/dts issues between 2.6.31 and 2.6.32 only to not make any headway on the USB Host drivers... As far as I can tell, the configuration of the USB transceiver over the ULPI interface is all controlled by the source code within dwc_otg_driver.o and dwc_otg_cil.c. I even had to make the same changes/fixes/workarounds between the two versions of drivers to get the -DDEBUG option to build to get visibility into the DWC-OTG drivers...

I guess my question boils down to this: Is it absolutely necessary to upgrade to 2.6.32 to get the host USB interface working or is that just to be synchronized with the latest and greatest to better address my concerns?

Mark Malopy


________________________________________
From: Wolfgang Denk [wd at denx.de]
Sent: Monday, March 29, 2010 3:07 PM
To: Mark Malopy
Cc: eldk at lists.denx.de
Subject: Re: [ELDK] Linux DWC OTG Driver - Host mode

Dear Mark Malopy,

In message <FFB4D2C9F87A7F49B23EE109E6F0A7E1010D07FEFD at VMBX124.ihostexchange.net> you wrote:
>
> Before posting my message, I did try what I thought was the latest code fro=
> m the following directory:
>
> http://git.denx.de/?p=linux-2.6-denx.git;a=tree;f=drivers/usb/gadget/dwc_otg;hb=HEAD

This is just a single directory, and "HEAD" is just a current
snapshot, so it may be anything depending on when you pull from the
repository.  Please make sure to checkout the whole tree.

As you can see from the images we provide for download at
ftp://ftp.denx.de/pub/linux/images/appliedmicro/kilauea/, the latest
fully tested version we provide is 2.6.32.7-00007-g08eba26 (i. e. you
can check out git commit ID 08eba26 to be sure to use the very same
code).

> Can you confirm whether or not this was the latest DWC-OTG drivers? Or did
> I also need to sync up the entire Kernel and/or driver directory?

Yes, you always should update the whole kenrel tree and use a
consistent state. Just updating a few random files (probably missing
the corresponding header files and oher related changes) is likely do
produce random behaviour.

Best regards,

Wolfgang Denk

--
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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minute.  But let him sit on a hot stove for a minute -- and it's lon-
ger than any hour. That's relativity.              -- Albert Einstein