Re: [PATCH 00/13] usb: dwc3: meson: add OTG support for GXL/GXM

[Neil Armstrong <narmstrong@baylibre.com>]

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On 14/05/2020 14:59, Felipe Balbi wrote:
> Neil Armstrong <narmstrong@baylibre.com> writes:
> 
>> Hi,
>>
>> On 14/05/2020 12:23, Felipe Balbi wrote:
>>> Felipe Balbi <balbi@kernel.org> writes:
>>>
>>>> Neil Armstrong <narmstrong@baylibre.com> writes:
>>>>
>>>>> The USB support was initialy done with a set of PHYs and dwc3-of-simple
>>>>> because the architecture of the USB complex was not understood correctly
>>>>> at the time (and proper documentation was missing...).
>>>>>
>>>>> But with the G12A family, the USB complex was correctly understood and
>>>>> implemented correctly.
>>>>> But seems the G12A architecture was derived for the GXL USB architecture,
>>>>> with minor differences and looks we can share most of the USB DWC3 glue
>>>>> driver.
>>>>>
>>>>> This patchset refactors and adds callbacks to handle the architecture
>>>>> difference while keeping the main code shared.
>>>>>
>>>>> The main difference is that on GXL/GXM the USB2 PHY control registers
>>>>> are mixed with the PHY registers (we already handle correctly), and
>>>>> the GLUE registers are allmost (99%) the same as G12A.
>>>>>
>>>>> But, the GXL/GXM HW is buggy, here are the quirks :
>>>>> - for the DWC2 controller to reset correctly, the GLUE mux must be switched
>>>>>   to peripheral when the DWC2 controlle probes. For now it's handled by simply
>>>>>   switching to device when probing the subnodes, but it may be not enough
>>>>> - when manually switching from Host to Device when the USB port is not
>>>>>   populated (should not happen with proper Micro-USB/USB-C OTG switch), it
>>>>>   makes the DWC3 to crash. The only way to avoid that is to use the Host
>>>>>   Disconnect bit to disconnect the DWC3 controller from the port, but we can't
>>>>>   recover the Host functionnality unless resetting the DWC3 controller.
>>>>>   This bit is set when only manual switch is done, and a warning is printed
>>>>>   on manual switching.
>>>>>
>>>>> The patches 1-8 should be applied first, then either waiting the next release
>>>>> or if the usb maintainer can provide us a stable tag, we can use it to merge
>>>>> the DT and bindings.
>>>>
>>>> it's unclear to me if this series is ready to be merged. Can someone
>>>> confirm? If it is, can you resend with all reviewed by tags in place?
>>>
>>> Are we getting a v2 for this?
>>>
>>
>> Yes, even a v3 with reviews on all patches:
>> http://lkml.kernel.org/r/20200416121910.12723-1-narmstrong@baylibre.com
> 
> In that case, can you check that I have applied everything correctly in
> testing/next?
> 
> cheers
> 

Looks fine,

Thanks,
Neil



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