Re: [PATCH] usb: dwc3: qcom: Add support to skip phy management by USB core

[Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>]

On 9/9/2026 7:16 AM, Thinh Nguyen wrote:
> On Tue, Sep 08, 2026, Val Packett wrote:
>>
>> On 9/8/26 7:33 PM, Val Packett wrote:
>>>
>>> On 7/23/26 7:54 AM, Krishna Kurapati wrote:
>>>> DWC3 driver does manage phys itself sufficiently for Qualcomm platforms.
>>>> If xhci-skip-phy-init is not set, the HCD core does a phy_init and phy_
>>>> exit is done only when roothub is being destroyed. Due to this, during
>>>> system suspend in host mode, although phy_exit is done by DWC3 core, the
>>>> init_count on phy is never down to zero since HCD core also did an init.
>>>> consequently causing phy's exit routine to not be called. Hence, add
>>>> support to skip phy management by USB core.
>>>>
>>>> Some Exynos platforms still do rely on USB core for phy_calibrate calls,
>>>> hence disable USB core management for Qualcomm platforms only.
>>>>
>>>> Signed-off-by: Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>
>>>> ---
>>>> Link to PHY calibrate handling for Exynos platforms:
>>>> https://urldefense.com/v3/__https://lore.kernel.org/all/20190829053028.32438-1-m.szyprowski@samsung.com/__;!!A4F2R9G_pg!aoY0pB27Tlxo3u1RzNzwPHpGsjuAgJWtPeKMvDrL___6gEQb28ew8Rg-O1877xBHB92Zv2fY3_Zbb2aoEQY$
>>>>
>>>
>>> Hi,
>>>
>>> this was merged into -next a few days ago, and I'm seeing warnings on
>>> boot now:
>>>
>>> [    0.613188] sysfs: cannot create duplicate filename
>>> '/devices/platform/soc@0/a800000.usb/software_node'
>>> [    0.613195] CPU: 10 UID: 0 PID: 93 Comm: kworker/u49:0 Tainted: G
>>>      W           7.3.0-rc2-next-20260907-uwu+ #143 PREEMPT(full)
>>> [    0.613197] Tainted: [W]=WARN
>>> [    0.613198] Hardware name: Dell Inc. Latitude 7455/0FK7MX, BIOS
>>> 2.13.0 09/19/2025
>>> [    0.613199] Workqueue: events_unbound deferred_probe_work_func
>>> [    0.613206] Call trace:
>>> [..]
>>> [    0.613226]  device_create_managed_software_node+0xe8/0x108
>>> [    0.613227]  dwc3_qcom_probe+0x5a4/0x7b0
>>>
>>> There is indeed already a software node being created in the shared dwc3
>>> core code.
>>>
>>> Could there be any other consequences than a duplicate sysfs path?
>>>
>> Answering my own question: even worse messages when the controller switches
>> to gadget mode (which happens even with chargers when DRD is enabled)
>>
> 
> 
> Thanks for the report Val.
> 
> Hi Krishna,
> 
> Can you help send a revert patch until a proper change is in available?
> 
Sure, will send a revert patch.

Regards,
Krishna,