[PATCH v2] usb: gadget: f_mass_storage: Disable eps during disconnect

[Patrice CHOTARD]

On 6/17/26 13:14, Mattijs Korpershoek wrote:
> When trying two ums commands in a row, the second one no longer
> enumerates properly from the host.
> 
> This happens since commit
> 59310d1ecb9f ("usb: gadget: introduce 'enabled' flag in struct usb_ep")
> causing usb_ep_enable() to return early when ep->enabled is already set.
> 
> Gadget function drivers (such as f_fastboot or f_mass_storage) implement
> a disable() function which is called whenever we are done using the
> gadget.
> 
> Because f_mass_storage driver does not disable the endpoints,
> ep->enabled will never be set to false again.
> 
> This can be reproduced on the STM32MP157C-DK2 or the Khadas VIM3 boards.
> 
> Add calls to usb_ep_disable() as done in linux [1] to fix this.
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9fff139aeb11186fd8e75860c959c86cb43ab2f6
> 
> Fixes: 59310d1ecb9f ("usb: gadget: introduce 'enabled' flag in struct usb_ep")
> Reported-by: Patrice Chotard <patrice.chotard at foss.st.com>
> Signed-off-by: Mattijs Korpershoek <mkorpershoek at kernel.org>
> ---
> This was initially reported by Patrice Chotard at:
> https://lore.kernel.org/all/20260616-ums_fix-v1-1-f1f6c903b3fc@foss.st.com/
> 
> That thread contains reproduction steps.
> ---
> Changes in v2:
> - Add missing Reported-by to commit message
> - Link to v1: https://patch.msgid.link/20260617-ums-disconnect-v1-1-a5ff9011d49a@kernel.org
> ---
>  drivers/usb/gadget/f_mass_storage.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
> index 71dc58da3f03..87ed25e8bb3a 100644
> --- a/drivers/usb/gadget/f_mass_storage.c
> +++ b/drivers/usb/gadget/f_mass_storage.c
> @@ -2275,6 +2275,17 @@ static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
>  static void fsg_disable(struct usb_function *f)
>  {
>  	struct fsg_dev *fsg = fsg_from_func(f);
> +
> +	/* Disable the endpoints */
> +	if (fsg->bulk_in_enabled) {
> +		usb_ep_disable(fsg->bulk_in);
> +		fsg->bulk_in_enabled = 0;
> +	}
> +	if (fsg->bulk_out_enabled) {
> +		usb_ep_disable(fsg->bulk_out);
> +		fsg->bulk_out_enabled = 0;
> +	}
> +
>  	fsg->common->new_fsg = NULL;
>  	raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
>  }
> 
> ---
> base-commit: a7830e87555abfb81cc69275cecb2bc0fbde5b28
> change-id: 20260617-ums-disconnect-d839bc17a47d
> 
> Best regards,
> --  
> Mattijs Korpershoek <mkorpershoek at kernel.org>
> 


Hi Mattijs

Tested on STM32MP157c-dk2 board.
Reviewed-by: Patrice Chotard <patrice.chotard at foss.st.com>

Thanks