Re: [PATCH] usb: dwc3: imx8mp: fix software node kernel dump

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

On Mon, Nov 25, 2024, Xu Yang wrote:
> When unbind and bind the device again, kernel will dump below warning:
> 
> [  173.972130] sysfs: cannot create duplicate filename '/devices/platform/soc/4c010010.usb/software_node'
> [  173.981564] CPU: 2 UID: 0 PID: 536 Comm: sh Not tainted 6.12.0-rc6-06344-g2aed7c4a5c56 #144
> [  173.989923] Hardware name: NXP i.MX95 15X15 board (DT)
> [  173.995062] Call trace:
> [  173.997509]  dump_backtrace+0x90/0xe8
> [  174.001196]  show_stack+0x18/0x24
> [  174.004524]  dump_stack_lvl+0x74/0x8c
> [  174.008198]  dump_stack+0x18/0x24
> [  174.011526]  sysfs_warn_dup+0x64/0x80
> [  174.015201]  sysfs_do_create_link_sd+0xf0/0xf8
> [  174.019656]  sysfs_create_link+0x20/0x40
> [  174.023590]  software_node_notify+0x90/0x100
> [  174.027872]  device_create_managed_software_node+0xec/0x108
> ...
> 
> The root cause is the '4c010010.usb' device is a platform device which is
> created during initcall and it will never be removed. So the software node
> will never be removed too even using device_create_managed_software_node().
> This will use device_add/remove_software_node() to improve the logic.
> 
> Fixes: a9400f1979a0 ("usb: dwc3: imx8mp: add 2 software managed quirk properties for host mode")
> Cc: stable@vger.kernel.org
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
> ---
>  drivers/usb/dwc3/dwc3-imx8mp.c | 26 +++++++++++++-------------
>  1 file changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-imx8mp.c b/drivers/usb/dwc3/dwc3-imx8mp.c
> index 356812cbcd88..edd544c6e1c1 100644
> --- a/drivers/usb/dwc3/dwc3-imx8mp.c
> +++ b/drivers/usb/dwc3/dwc3-imx8mp.c
> @@ -129,6 +129,16 @@ static void dwc3_imx8mp_wakeup_disable(struct dwc3_imx8mp *dwc3_imx)
>  	writel(val, dwc3_imx->hsio_blk_base + USB_WAKEUP_CTRL);
>  }
>  
> +static const struct property_entry dwc3_imx8mp_properties[] = {
> +	PROPERTY_ENTRY_BOOL("xhci-missing-cas-quirk"),
> +	PROPERTY_ENTRY_BOOL("xhci-skip-phy-init-quirk"),
> +	{},
> +};
> +
> +static const struct software_node dwc3_imx8mp_swnode = {
> +	.properties = dwc3_imx8mp_properties,
> +};
> +
>  static irqreturn_t dwc3_imx8mp_interrupt(int irq, void *_dwc3_imx)
>  {
>  	struct dwc3_imx8mp	*dwc3_imx = _dwc3_imx;
> @@ -148,17 +158,6 @@ static irqreturn_t dwc3_imx8mp_interrupt(int irq, void *_dwc3_imx)
>  	return IRQ_HANDLED;
>  }
>  
> -static int dwc3_imx8mp_set_software_node(struct device *dev)
> -{
> -	struct property_entry props[3] = { 0 };
> -	int prop_idx = 0;
> -
> -	props[prop_idx++] = PROPERTY_ENTRY_BOOL("xhci-missing-cas-quirk");
> -	props[prop_idx++] = PROPERTY_ENTRY_BOOL("xhci-skip-phy-init-quirk");
> -
> -	return device_create_managed_software_node(dev, props, NULL);
> -}
> -
>  static int dwc3_imx8mp_probe(struct platform_device *pdev)
>  {
>  	struct device		*dev = &pdev->dev;
> @@ -221,10 +220,10 @@ static int dwc3_imx8mp_probe(struct platform_device *pdev)
>  	if (err < 0)
>  		goto disable_rpm;
>  
> -	err = dwc3_imx8mp_set_software_node(dev);
> +	err = device_add_software_node(dev, &dwc3_imx8mp_swnode);

You need to check all the fail cases after this to properly remove the
software node.

BR,
Thinh

>  	if (err) {
>  		err = -ENODEV;
> -		dev_err(dev, "failed to create software node\n");
> +		dev_err(dev, "failed to add software node\n");
>  		goto disable_rpm;
>  	}
>  
> @@ -268,6 +267,7 @@ static void dwc3_imx8mp_remove(struct platform_device *pdev)
>  
>  	pm_runtime_get_sync(dev);
>  	of_platform_depopulate(dev);
> +	device_remove_software_node(dev);
>  
>  	pm_runtime_disable(dev);
>  	pm_runtime_put_noidle(dev);
> -- 
> 2.34.1
>