Re: musb: am3358: having problem with high-speed on usb1 at peripheral

From: Felipe Balbi
Date: Thu Aug 18 2016 - 02:36:01 EST



Hi,

ayaka <ayaka@xxxxxxxxxxx> writes:
>>>>>> On 08/13/2016 01:44 AM, Greg KH wrote:
>>>>>>> On Sat, Aug 13, 2016 at 12:38:46AM +0800, ayaka wrote:
>>>>>>>
>>>>>>>> On 08/12/2016 03:40 PM, Greg KH wrote:
>>>>>>>>> On Fri, Aug 12, 2016 at 10:23:15AM +0800, ayaka wrote:
>>>>>>>>> Hello all:
>>>>>>>>> I recently add a support for customize am3358 board using the branch
>>>>>>>>> processor-sdk-linux-03.00.00 from Ti git. But I meet a problem with musb
>>>>>>>>> at the peripheral mode.
>>>>>>>> Then you are going to have to get support from TI for this, nothing we
>>>>>>>> can do here about random vendor kernel trees, sorry.
>>>>>>>>
>>>>>>>> If you can use the 4.7 tree, or better yet, the 4.8-rc tree, then we
>>>>>>> I have tried the 4.8-rc1, I meet the same problem.
>>>>>> What problem is that exactly?
>>>>> Sorry, the USB1 can't work at high speed gadget mode and have DMA problem.
>>>>> musb-hdrc musb-hdrc.0.auto: Failed to request rx1.
>>>>> musb-hdrc musb-hdrc.0.auto: musb_init_controller failed with status -517
>>>> -517 is EPROBE_DEFER. Most likely DMA hasn't probed and MUSB is
>>>> deferring to try later. This does _NOT_ MUSB can't work with
>>>> DMA. Perhaps you didn't enable support for MUSB's DMA engine.
>>>>
>>> I have set the status of cppi41dma to okay in dts. And CONFIG_USB_TI_CPPI41_DMA,
>>> CONFIG_TI_CPPI41 and CONFIG_TI_EDMA are enabled with build into kernel.
>>>
>>> Anything else I should do?
>> no, that should do it. Since musb returned -EPROBE_DEFER, it will retry
>> probing later. Check if musb probed fine. The easiest way is to check if
>> you have anything in /sys/class/udc/
> Yes, it has musb-hdrc.0.auto. But it doesn't mean that it fallback PIO mode?

no, it doesn't. MUSB knows it needs the DMA, that's why is defers its
own probe routine.

> Actually I don't care whether it use PIO or DMA, I just can't bear it
> work in USB 2.0 Full Speed mode, too slow.

So it always enumerates in Full-speed? That's odd. Bin, any ideas?

--
balbi

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