Re: [PATCH 1/1] mfd: omap-usb-host: Fix USB device detection problems on OMAP4 Panda

[Roger Quadros <rogerq@ti.com>]

On 12/02/2013 02:01 PM, Sebastian Andrzej Siewior wrote:
> - stable@vger.kernel.org since they probably don't care about this
>   unless the patch is merged.
> 
> On 12/02/2013 10:41 AM, Roger Quadros wrote:
>> Michael,
>>
>> On 11/29/2013 05:32 PM, Michael Trimarchi wrote:
>>> Hi Roger
>>>
>>> On Fri, Nov 29, 2013 at 2:01 PM, Roger Quadros <rogerq@ti.com> wrote:
>>>> With u-boot 2013.10, USB devices are sometimes not detected
>>>> on OMAP4 Panda. To make us independent of what bootloader does
>>>> with the USB Host module, we must RESET it to get it to a known
>>>> good state. This patch Soft RESETs the USB Host module.
>>>>
>>>
>>> Do you think that we need something similar of usb musb?
>>> I have seen the OTG_SYSCONFIG is touched in uboot and
>>> only readed in omap2430.c.
>>
>> I'm not sure about musb. Maybe Sebastian/Felipe have better idea.
>> In general I believe that all modules must be reset by the kernel.
>>
> 
> based on the code at the bottom it touches the first few register(s)
> sysconfig. Isn't hwmod actually doing this idle stuff and resting the
> device during boot?
> 

You are right. The musb hwmod data doesn't have the HWMOD_INIT_NO_RESET
flag, so hwmod should reset it during boot.

Maybe I too should just remove HWMOD_INIT_NO_RESET flag from the USB Host
hwmod data, then we don't need to change this driver at all.

Benoit, Tony any comments?

cheers,
-roger