linux-kernel - Re: [PATCH v4] usb: dwc3: Don't switch OTG -> peripheral if extcon is present

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Date:   Thu, 22 Sep 2022 22:35:14 +0200
From:   Ferry Toth <fntoth@...il.com>
To:     Andy Shevchenko <andriy.shevchenko@...el.com>
Cc:     Andrey Smirnov <andrew.smirnov@...il.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Felipe Balbi <balbi@...nel.org>,
        Thinh Nguyen <thinhn@...opsys.com>, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Thinh Nguyen <Thinh.Nguyen@...opsys.com>
Subject: Re: [PATCH v4] usb: dwc3: Don't switch OTG -> peripheral if extcon is
 present

Hi,

Op 22-09-2022 om 15:29 schreef Andy Shevchenko:
> On Thu, Sep 22, 2022 at 12:23:04PM +0200, Ferry Toth wrote:
>> On 22-09-2022 12:08, Andy Shevchenko wrote:
>>> On Sun, Apr 03, 2022 at 09:49:07AM -0700, Andrey Smirnov wrote:
>>>> If the extcon device exists, get the mode from the extcon device. If
>>>> the controller is DRD and the driver is unable to determine the mode,
>>>> only then default the dr_mode to USB_DR_MODE_PERIPHERAL.
>>> According to Ferry (Cc'ed) this broke Intel Merrifield platform. Ferry, can you
>>> share bisect log?
git bisect start
# bad: [3d7cb6b04c3f3115719235cc6866b10326de34cd] Linux 5.19
git bisect bad 3d7cb6b04c3f3115719235cc6866b10326de34cd
# good: [4b0986a3613c92f4ec1bdc7f60ec66fea135991f] Linux 5.18
git bisect good 4b0986a3613c92f4ec1bdc7f60ec66fea135991f
# good: [c011dd537ffe47462051930413fed07dbdc80313] Merge tag 
'arm-soc-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
git bisect good c011dd537ffe47462051930413fed07dbdc80313
# good: [5d4af9c1f04ab0411ba5818baad9a68e87f33099] Merge branch 
'mv88e6xxx-fixes-for-reading-serdes-state'
git bisect good 5d4af9c1f04ab0411ba5818baad9a68e87f33099
# bad: [7a68065eb9cd194cf03f135c9211eeb2d5c4c0a0] Merge tag 
'gpio-fixes-for-v5.19-rc2' of 
git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
git bisect bad 7a68065eb9cd194cf03f135c9211eeb2d5c4c0a0
# bad: [54c2cc79194c961a213c1d375fe3aa4165664cc4] Merge tag 
'usb-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
git bisect bad 54c2cc79194c961a213c1d375fe3aa4165664cc4
# good: [6a31a95135da0bb2c5349e49e37d76e9909ab7ea] staging: r8188eu: 
remove include/rtw_debug.h
git bisect good 6a31a95135da0bb2c5349e49e37d76e9909ab7ea
# good: [04d93b2b8bc7a68ec45a6a156f34a611ede5aa60] Merge tag 
'spdx-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx
git bisect good 04d93b2b8bc7a68ec45a6a156f34a611ede5aa60
# good: [c069d2756c01ed36121fae6a42c14fdf1325c71d] serial: sifive: 
Sanitize CSIZE and c_iflag
git bisect good c069d2756c01ed36121fae6a42c14fdf1325c71d
# bad: [3120aac6d0ecd9accf56894aeac0e265f74d3d5a] usb: dwc2: gadget: 
don't reset gadget's driver->bus
git bisect bad 3120aac6d0ecd9accf56894aeac0e265f74d3d5a
# bad: [0f01017191384e3962fa31520a9fd9846c3d352f] usb: dwc3: Don't 
switch OTG -> peripheral if extcon is present
git bisect bad 0f01017191384e3962fa31520a9fd9846c3d352f
# good: [b8a19881337678c02bb3d72ae821602e1a4c377d] usb: gadget: u_audio: 
clean up some inconsistent indenting
git bisect good b8a19881337678c02bb3d72ae821602e1a4c377d
# good: [424bef51fa530389b0b9008c9e144e40c10e8458] usb: musb: Fix 
missing of_node_put() in omap2430_probe
git bisect good 424bef51fa530389b0b9008c9e144e40c10e8458

>>> I can but not right now. But what I did was bisect between 5.18.0 (good) and
>>> 5.19.0 (bad) then when I got near the culprit (~20 remaining) based on the
>>> commit message I tried 0f01017191384e3962fa31520a9fd9846c3d352f "usb: dwc3:
>>> Don't switch OTG -> peripheral if extcon is present" (bad) and commit before
>>> that (good).
5c29e864999763baec9eedb9ea5bd557aa4cbd77
>>> The effect of the patch is that on Merrifield (I tested with Intel Edison
>>> Arduino board which has a HW switch to select between host and device mode)
>>> device mode works but in host mode USB is completely not working.
>>>
>>> Currently on host mode - when working - superfluous error messages from
>>> tusb1210 appear. When host mode is not working there are no tusb1210
>>> messages in the logs / on the console at all. Seemingly tusb1210 is not
>>> probed, which points in the direction of a relation to extcon.
>>>
>>> Taking into account the late cycle, I would like to revert the change. And
>>> Ferry and I would help to test any other (non-regressive) approach).
>> I have not yet tested if a simple revert fixes the problem but will tonight.
> For clean revert you might need to revert the merge conflict fixes first:
> 8bd6b8c4b100 ("USB: fixup for merge issue with "usb: dwc3: Don't switch
> OTG -> peripheral if extcon is present"").

Tested successfully on Intel Merrifield with v6.0-rc6 with reverted:

8bd6b8c4 ("USB: fixup for merge issue with "usb: dwc3: Don't switch OTG -> peripheral if extcon is present"")

0f010171 ("usb: dwc3: Don't switch OTG -> peripheral if extcon is present")

I also tested on v5.19 which in addition requires a back port of

d4a0a189 ("phy: ti: tusb1210: Don't check for write errors when powering 
on")

>> I would be happy to test other approaches too.