Re: [PATCH v3] usb: dwc3: core: Do core softreset when switch mode

[Ferry Toth <fntoth@gmail.com>]

Hi

Op 17-04-2021 om 16:22 schreef Ferry Toth:
> Hi
>
> Op 17-04-2021 om 04:27 schreef Thinh Nguyen:
>> Ferry Toth wrote:
>>> Hi
>>>
>>> Op 16-04-2021 om 00:23 schreef Thinh Nguyen:
>>>> Thinh Nguyen wrote:
>>>>> From: Yu Chen <chenyu56@huawei.com>
>>>>> From: John Stultz <john.stultz@linaro.org>
>>>>>
>>>>> According to the programming guide, to switch mode for DRD 
>>>>> controller,
>>>>> the driver needs to do the following.
>>>>>
>>>>> To switch from device to host:
>>>>> 1. Reset controller with GCTL.CoreSoftReset
>>>>> 2. Set GCTL.PrtCapDir(host mode)
>>>>> 3. Reset the host with USBCMD.HCRESET
>>>>> 4. Then follow up with the initializing host registers sequence
>>>>>
>>>>> To switch from host to device:
>>>>> 1. Reset controller with GCTL.CoreSoftReset
>>>>> 2. Set GCTL.PrtCapDir(device mode)
>>>>> 3. Reset the device with DCTL.CSftRst
>>>>> 4. Then follow up with the initializing registers sequence
>>>>>
>>>>> Currently we're missing step 1) to do GCTL.CoreSoftReset and step 
>>>>> 3) of
>>>>> switching from host to device. John Stult reported a lockup issue 
>>>>> seen
>>>>> with HiKey960 platform without these steps[1]. Similar issue is 
>>>>> observed
>>>>> with Ferry's testing platform[2].
>>>>>
>>>>> So, apply the required steps along with some fixes to Yu Chen's 
>>>>> and John
>>>>> Stultz's version. The main fixes to their versions are the missing 
>>>>> wait
>>>>> for clocks synchronization before clearing GCTL.CoreSoftReset and 
>>>>> only
>>>>> apply DCTL.CSftRst when switching from host to device.
>>>>>
>>>>> [1]
>>>>> https://urldefense.com/v3/__https://lore.kernel.org/linux-usb/20210108015115.27920-1-john.stultz@linaro.org/__;!!A4F2R9G_pg!PW9Jbs4wv4a_zKGgZHN0FYrIpfecPX0Ouq9V3d16Yz-9-GSHqZWsfBAF-WkeqLhzN4i3$ 
>>>>>
>>>>>
>>>>> [2]
>>>>> https://urldefense.com/v3/__https://lore.kernel.org/linux-usb/0ba7a6ba-e6a7-9cd4-0695-64fc927e01f1@gmail.com/__;!!A4F2R9G_pg!PW9Jbs4wv4a_zKGgZHN0FYrIpfecPX0Ouq9V3d16Yz-9-GSHqZWsfBAF-WkeqGeZStt4$ 
>>>>>
>>>>>
>>>>>
>>>>> Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
>>>>> Cc: Ferry Toth <fntoth@gmail.com>
>>>>> Cc: Wesley Cheng <wcheng@codeaurora.org>
>>>>> Cc: <stable@vger.kernel.org>
>>>>> Fixes: 41ce1456e1db ("usb: dwc3: core: make dwc3_set_mode() work
>>>>> properly")
>>>>> Signed-off-by: Yu Chen <chenyu56@huawei.com>
>>>>> Signed-off-by: John Stultz <john.stultz@linaro.org>
>>>>> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
>>>>> ---
>>>>> Changes in v3:
>>>>> - Check if the desired mode is OTG, then keep the old flow
>>>>> - Remove condition for OTG support only since the device can still be
>>>>>     configured DRD host/device mode only
>>>>> - Remove redundant hw_mode check since __dwc3_set_mode() only applies
>>>>> when
>>>>>     hw_mode is DRD
>>>>> Changes in v2:
>>>>> - Initialize mutex per device and not as global mutex.
>>>>> - Add additional checks for DRD only mode
>>>>>
>>>>>    drivers/usb/dwc3/core.c | 27 +++++++++++++++++++++++++++
>>>>>    drivers/usb/dwc3/core.h |  5 +++++
>>>>>    2 files changed, 32 insertions(+)
>>>>>
>>>> Hi John,
>>>>
>>>> If possible, can you run a test with this version on your platform?
>>>>
>>>> Thanks,
>>>> Thinh
>>>>
>>> I tested this on edison-arduino with this patch on top of usb-next
>>> (5.12-rc7 + "increase BESL baseline to 6" to prevent throttling").
>>>
>>> On this platform there is a physical switch to switch roles. With this
>>> patch I find:
>>>
>>> - switch to host mode always works fine
>>>
>>> - switch to gadget mode I need to flip the switch 3x 
>>> (gadget-host-gadget).
>>>
>>> An error message appears on the gadget side "dwc3 dwc3.0.auto: timed 
>>> out
>>> waiting for SETUP phase" appears, but then the device connects to my 
>>> PC,
>>> no throttling.
>>>
>>> - alternatively I can switch to gadget 1x and then unplug/replug the 
>>> cable.
>>>
>>> No error message and connects fine.
>>>
>>> - if I flip the switch only once, on the PC side I get:
>>>
>>>    kernel: usb 1-5: new high-speed USB device number 18 using xhci_hcd
>>>    kernel: usb 1-5: New USB device found, idVendor=1d6b,
>>>    idProduct=0104, bcdDevice= 1.00 kernel: usb 1-5: New USB device
>>>    strings: Mfr=1, Product=2, SerialNumber=3 kernel: usb 1-5: Product:
>>>    USBArmory Gadget kernel: usb 1-5: Manufacturer: USBArmory kernel:
>>>    usb 1-5: SerialNumber: 0123456789abcdef kernel: usb 1-5: can't set
>>>    config #1, error -110
>> The device failed at set_configuration() request and timed out. It
>> probably timed out from the status stage looking at the device err 
>> print.
>>
>>> Then if I wait long enough on the gadget side I get:
>>>
>>>    root@yuna:~# ifconfig
>>>
>>>    usb0: flags=-28605<UP,BROADCAST,RUNNING,MULTICAST,DYNAMIC> mtu 1500
>>>    inet 169.254.119.239 netmask 255.255.0.0 broadcast 169.254.255.255
>>>    inet6 fe80::a8bb:ccff:fedd:eef1 prefixlen 64 scopeid 0x20<link>
>>>    ether aa:bb:cc:dd:ee:f1 txqueuelen 1000 (Ethernet) RX packets 490424
>>>    bytes 735146578 (701.0 MiB) RX errors 0 dropped 191 overruns 0 frame
>>>    0 TX packets 35279 bytes 2532746 (2.4 MiB) TX errors 0 dropped 0
>>>    overruns 0 carrier 0 collisions 0
>>>
>>> (correct would be: inet 10.42.0.221 netmask 255.255.255.0 broadcast
>>> 10.42.0.255)
>>>
>>> So much improved now, but it seems I am still missing something on 
>>> plug.
>>>
>> That's great! We can look at it further. Can you capture the tracepoints
>> of the issue. Also, can you try with mass_storage gadget to see if the
>> result is the same?
>
> I have already gser, eem, mass_storage and uac2 combo. When eem fails, 
> the mass_storage and uac2 don't appear (on KDE you get all kind of 
> popups when they appear).
>
> So either all works, or all fails.
>
> I'll trace this later today.

Trace capturing switch from host-> gadget  here 
https://github.com/andy-shev/linux/files/6329600/5.12-rc7%2Busb-next.zip

(Issue history: https://github.com/andy-shev/linux/issues/31)

On the PC side this resulted to:

apr 17 18:17:44 delfion kernel: usb 1-5: new high-speed USB device 
number 12 using xhci_hcd
apr 17 18:17:44 delfion kernel: usb 1-5: New USB device found, 
idVendor=1d6b, idProduct=0104, bcdDevice= 1.00
apr 17 18:17:44 delfion kernel: usb 1-5: New USB device strings: Mfr=1, 
Product=2, SerialNumber=3
apr 17 18:17:44 delfion kernel: usb 1-5: Product: USBArmory Gadget
apr 17 18:17:44 delfion kernel: usb 1-5: Manufacturer: USBArmory
apr 17 18:17:44 delfion kernel: usb 1-5: SerialNumber: 0123456789abcdef
apr 17 18:17:49 delfion kernel: usb 1-5: can't set config #1, error -110


Thanks for all your help!

>
>> Thanks,
>> Thinh