Re: [PATCH v2] usb: gadget: goku_udc: fix kobject warning on probe failure

[Greg Kroah-Hartman]

On Wed, Aug 26, 2026 at 04:26:47PM +0800, Cheng Lingfei wrote:
> goku_probe() calls goku_remove() when hardware initialization fails, but
> the gadget device is initialized only near the end of probe. As a result,
> goku_remove() calls usb_del_gadget_udc(), which drops a reference to an
> uninitialized gadget device and triggers a kobject warning.
> 
> Initialize the gadget device immediately after allocating the controller,
> but add it only after all hardware resources have been acquired. Track the
> gadget registration state so goku_remove() can safely clean up both partial
> probe state and a fully initialized device.
> 
> Use the split gadget removal API and drop the final gadget reference only
> after all hardware resources have been released. Obtain the controller from
> the embedded gadget device in the release callback because driver data is
> set on the PCI device rather than the gadget device.
> 
> The legacy diagnostic proc entry uses a single global name. This causes a
> collision when more than one controller is probed. Replace it with a
> per-device debugfs entry.
> 
> Fixes: 3301c215a2bb ("USB: UDC: Expand device model API interface")
> Reported-by: syzbot+06ec7624018233e17113@xxxxxxxxxxxxxxxxxxxxxxxxx
> Closes: https://syzkaller.appspot.com/bug?extid=06ec7624018233e17113
> Tested-by: syzbot+06ec7624018233e17113@xxxxxxxxxxxxxxxxxxxxxxxxx
> Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Link: https://lore.kernel.org/2026082616-glue-atlas-0cfd@gregkh
> Assisted-by: Codex:gpt-5.6
> Signed-off-by: Cheng Lingfei <chenglingfei@xxxxxxxxxxx>
> ---
> Changes in v2:
> - Replace legacy procfs with per-device debugfs entries.

debugfs changes should be a separate change, please make this a patch
series.

thanks,

greg k-h