Re: [PATCH 06/19] usb: gadget: snps_udc_plat: lock out the interrupt

[Herve Codina <herve.codina@bootlin.com>]

Hi Greg,

On Tue, 27 Oct 2026 15:57:46 +0100
Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:

> From: Josef Bacik <josef@toxicpanda.com>
> 
> stop_udc() is called from a work item, when the extcon device reports
> that the cable has been unplugged.  It takes udc->lock with interrupts
> enabled.  udc_irq(), the hard interrupt handler of the controller, takes
> the same lock.  If the controller raises an interrupt on the CPU which
> is in stop_udc(), and it is likely to have something to report when the
> cable is pulled, the handler spins on a lock which the interrupted work
> holds: the CPU is stuck.
> 
> Disable interrupts while the lock is held.  They are enabled again for
> the ->disconnect() callback of the gadget driver, for which the lock is
> dropped as before.
> 
> Fixes: 1b9f35adb0ff ("usb: gadget: udc: Add Synopsys UDC Platform driver")
> Cc: stable <stable@kernel.org>
> Cc: Neill Kapron <nkapron@google.com>
> Cc: Ijae Kim <ae878000@gmail.com>
> Cc: Herve Codina <herve.codina@bootlin.com>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>  drivers/usb/gadget/udc/snps_udc_plat.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 

LGTM.

Reviewed-by: Herve Codina <herve.codina@bootlin.com>

Best regards,
Hervé