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

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Wed, Sep 09, 2026, Krishna Kurapati wrote:
> This reverts commit be7b1c68cd3e4fc0f5a4e1b85696de1052f21f2f.
> 
> Commit be7b1c68cd3e ("usb: dwc3: qcom: Add support to skip phy management by USB core")
> is causing a regression on qualcomm platforms.
> 
> During role switch it tends to cause the following crash:
> 
> [    5.620951] refcount_t: underflow; use-after-free.
> [    5.621114] Call trace:
> [    5.621115]  refcount_warn_saturate+0xd8/0x140 (P)
> [    5.621117]  kobject_put+0x11c/0x230
> [    5.621121]  software_node_notify_remove+0xdc/0xf8
> [    5.621124]  device_del+0x1dc/0x328
> [    5.621126]  usb_disconnect+0x1d8/0x348
> [    5.621129]  usb_remove_hcd+0x100/0x2a8
> [    5.621131]  xhci_plat_remove+0x8c/0x170
> [    5.621134]  platform_remove+0x28/0x40
> [    5.621135]  device_release_driver_internal+0x174/0x290
> [    5.621138]  device_release_driver+0x20/0x38
> [    5.621140]  bus_remove_device+0x19c/0x1f8
> [    5.621142]  device_del+0x1c4/0x328
> [    5.621143]  platform_device_unregister+0x34/0xc0
> [    5.621145]  dwc3_host_exit+0x50/0x70
> [    5.621146]  __dwc3_set_mode+0xa4/0x378
> 
> [    5.644535] Unable to handle kernel paging request at virtual address
> [    5.644657] Workqueue: events_freezable __dwc3_set_mode
> [    5.644664] pc : __pi_strcmp+0x9c/0x140
> [    5.644668] lr : software_node_property_present+0x60/0x98
> [    5.644697] Call trace:
> [    5.644698]  __pi_strcmp+0x9c/0x140 (P)
> [    5.644700]  device_property_present+0x9c/0xc0
> [    5.644703]  dwc3_gadget_init+0x230/0x7b0
> [    5.644704]  __dwc3_set_mode+0x314/0x378
> [    5.644707]  process_scheduled_works+0x1b8/0x538
> [    5.644710]  worker_thread+0x1fc/0x2f8
> [    5.644711]  kthread+0x114/0x148
> [    5.644713]  ret_from_fork+0x10/0x20
> 
> Revert skipping of usb core phy management for Qualcomm platforms to avoid
> the above issues.
> 
> Reported-by: Val Packett <val@packett.cool>
> Closes: https://urldefense.com/v3/__https://lore.kernel.org/all/f9926203-ee69-4e18-b6c7-95261ba10807@packett.cool/__;!!A4F2R9G_pg!ZuwuOzXLwm-pammHnrjJpfODYLL9KLgum4PiPdImtCF772khuW9jycQW4H2IVZsMxYiIY52jfTIfx-DfXKUA4iBeL3Nbptfnlcw8_A$ 
> Signed-off-by: Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 15 ---------------
>  1 file changed, 15 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index ba26e61df915..ac68b4218b56 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -19,7 +19,6 @@
>  #include <linux/iopoll.h>
>  #include <linux/usb/hcd.h>
>  #include <linux/usb.h>
> -#include <linux/property.h>
>  #include "core.h"
>  #include "glue.h"
>  
> @@ -420,16 +419,6 @@ static irqreturn_t qcom_dwc3_resume_irq(int irq, void *data)
>  	return IRQ_HANDLED;
>  }
>  
> -static int dwc3_qcom_set_swnode(struct device *dev)
> -{
> -	const struct property_entry props[] = {
> -		PROPERTY_ENTRY_BOOL("xhci-skip-phy-init-quirk"),
> -		{}
> -	};
> -
> -	return device_create_managed_software_node(dev, props, NULL);
> -}
> -
>  static void dwc3_qcom_select_utmi_clk(struct dwc3_qcom *qcom)
>  {
>  	/* Configure dwc3 to use UTMI clock as PIPE clock not present */
> @@ -694,10 +683,6 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	if (ignore_pipe_clk)
>  		dwc3_qcom_select_utmi_clk(qcom);
>  
> -	ret = dwc3_qcom_set_swnode(dev);
> -	if (ret)
> -		goto clk_disable;
> -
>  	qcom->mode = usb_get_dr_mode(dev);
>  
>  	if (qcom->mode == USB_DR_MODE_HOST) {
> 
> ---
> base-commit: 34c9c5517033a74039a54dfab24e7bf767a4e0e4
> change-id: 20260909-xhci-fixes-revert-59e68fe3b641
> 
> Best regards,
> --  
> Krishna Kurapati <krishna.kurapati@oss.qualcomm.com>
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Thanks,
Thinh