Re: [PATCH] ARM: dts: Odroid XU4: fix USB3.0 ports

[Marek Szyprowski <m.szyprowski@samsung.com>]

Hi Krzysztof,

On 2017-01-25 08:55, Krzysztof Kozlowski wrote:
> On Wed, Jan 25, 2017 at 7:51 AM, Anand Moon <linux.amoon@gmail.com> wrote:
>> On 24 January 2017 at 19:18, Richard Genoud <richard.genoud@gmail.com> wrote:
>>> Since commit 2164a476205ccc ("usb: dwc3: set SUSPHY bit for all cores"),
>>> the USB ports on odroid-XU4 don't work anymore.
>>>
>>> Inserting an usb key (USB2.0) on the USB3.0 port result in:
>>> [   64.488264] xhci-hcd xhci-hcd.2.auto: Port resume took longer than 20000 msec, port status = 0xc400fe3
>>> [   74.568156] xhci-hcd xhci-hcd.2.auto: xHCI host not responding to stop endpoint command.
>>> [   74.574806] xhci-hcd xhci-hcd.2.auto: Assuming host is dying, halting host.
>>> [   74.601970] xhci-hcd xhci-hcd.2.auto: HC died; cleaning up
>>> [   74.606276] usb 3-1: USB disconnect, device number 2
>>> [   74.613565] usb 4-1: USB disconnect, device number 2
>>> [   74.621208] usb usb3-port1: couldn't allocate usb_device
>>> NB: it's not related to USB2.0 devices, I get the same result with an USB3.0 device (SATA to USB3 for instance).
>>> NB2: it doesn't happen on an odriod-XU3 board, that doesn't have the realtek RTL8153 chip.
>>>
>>> If the lines:
>>>          if (dwc->revision > DWC3_REVISION_194A)
>>>                  reg |= DWC3_GUSB3PIPECTL_SUSPHY;
>>> are commented out, the USB3.0 start working.
>>>
>>> For a full analyse: https://lkml.org/lkml/2017/1/18/678
>>>
>>> Felipe suggested that suspend should be disabled temporarily while
>>> what's wrong with DCW3 is figured out.
>>>
>>> Tested on Odroid XU4
>>>
>>> Suggested-by: Felipe Balbi <felipe.balbi@linux.intel.com>
>>> Tested-by: Richard Genoud <richard.genoud@gmail.com>
>>> Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
>>> Cc: stable@vger.kernel.org # 4.4+
>>> Fixes: 2164a476205ccc ("usb: dwc3: set SUSPHY bit for all cores")
>>> ---
>>>   arch/arm/boot/dts/exynos5422-odroidxu4.dts | 9 +++++++++
>>>   1 file changed, 9 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/exynos5422-odroidxu4.dts b/arch/arm/boot/dts/exynos5422-odroidxu4.dts
>>> index 2faf88627a48..f62dbd9b5ad3 100644
>>> --- a/arch/arm/boot/dts/exynos5422-odroidxu4.dts
>>> +++ b/arch/arm/boot/dts/exynos5422-odroidxu4.dts
>>> @@ -43,6 +43,15 @@
>>>          status = "okay";
>>>   };
>>>
>>> +&usbdrd_dwc3_0 {
>>> +       /*
>>> +        * without that, usb devices are not recognized when
>>> +        * they are plugged.
>>> +        * cf: https://lkml.org/lkml/2017/1/18/678
>>> +        */
>>> +       snps,dis_u3_susphy_quirk;
>>> +};
>>> +
>>>   &usbdrd_dwc3_1 {
>>>          dr_mode = "host";
>>>   };
>>> --
>> Thanks for this patch.
>> But could you consider moving this changes as below.
>>
>> https://lkml.org/lkml/2015/3/18/400
> The patch above (and other DTS patches from the set) was not even sent
> to linux-samsung-soc nor to me... It is sad how easily one's work can
> disappear. Also, it is really worthless to solve the same problem
> twice.

Well, they were sent about 2 years ago... and you were also working on this
topic. ;)

> Cc Marek and Bartlomiej,
> Guys, do you want to continue with Robert's patch (linked above by
> Anand)? If yes, please take the ownership (Robert's address is not
> valid anymore). If not, I will take Richard's patch after
> resubmission.

Take Richard's patch because it has a bit more details describing why 
such quirk
is needed.

Richard: in Roberts patch there is also a quirk for USB 2.0 mode
(snps,dis_u2_susphy_quirk). Could you check if it really needed?

Maybe it would make sense to set those quirks for both DWC3 controllers, 
as this
issue with PHY suspend seems to be a Exynos specific thing.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland