On 9/7/26 11:07, Mattijs Korpershoek wrote:
> Hi Patrice,
>
> Thank you for the patch and sorry for the review delays.
>
> On Mon, Aug 17, 2026 at 17:41, Patrice Chotard <[email protected]>
> wrote:
>
>> schedule was added in sleep_thread() by commit 4b6a3e860878
>> ("usb: gadget: f_mass_storage: Add schedule() in sleep_thread()").
>> to ensure that watchdog is still reset periodically even on platform
>> that doesn't implement g_dnl_board_usb_cable_connected() and in case USB
>> cable is not connected.
>>
>> Instead of calling schedule() for each for() loop iteration, call
>> schedule() only in case g_dnl_board_usb_cable_connected() is not
>> overloaded, in this particular case, g_dnl_board_usb_cable_connected()'s
>> return value is -EOPNOTSUPP.
>>
>> Signed-off-by: Patrice Chotard <[email protected]>
>> ---
>> drivers/usb/gadget/f_mass_storage.c | 7 +++++--
>> 1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/f_mass_storage.c
>> b/drivers/usb/gadget/f_mass_storage.c
>> index 621852080e2..f467693d2cb 100644
>> --- a/drivers/usb/gadget/f_mass_storage.c
>> +++ b/drivers/usb/gadget/f_mass_storage.c
>> @@ -651,6 +651,7 @@ static void busy_indicator(void)
>> static int sleep_thread(struct fsg_common *common)
>> {
>> int i = 0, k = 0;
>> + int ret;
>>
>> /* Wait until a signal arrives or we are woken up */
>> for (;;) {
>> @@ -673,13 +674,15 @@ static int sleep_thread(struct fsg_common *common)
>> return -EPIPE;
>>
>> /* Check cable connection */
>> - if (!g_dnl_board_usb_cable_connected())
>> + ret = g_dnl_board_usb_cable_connected();
>> + if (!ret)
>> return -EIO;
>> + if (ret == -EOPNOTSUPP)
>> + schedule();
>
> What happens on boards that override g_dnl_board_usb_cable_connected()
> that return a positive value?
>
> Per my understanding, schedule() will never be called, and the watchdog
> will be triggered at some point, no?
Hi Mattijs,
In case g_dnl_board_usb_cable_connected() returns 1 (it's currently the case
on STM32MP157c-DK2 board), we stay inside sleep_thread() for(;;) loop until
common->thread_wakeup_needed is set to 1 by wakeup_thread().
wakeup_thread() is called periodically (around every second, it was what i
observed
during testing) by either bulk_out_complete() or bulk_in_complete().
Then we came back in fsg_main_thread() which was sleep_thread() caller,
and came back in while(1) loop of do_usb_mass_storage() where schedule() is
called.
So watchdog is reset periodically.
Patrice
>
>>
>> k = 0;
>> }
>>
>> - schedule();
>> dm_usb_gadget_handle_interrupts(udcdev);
>> }
>> common->thread_wakeup_needed = 0;
>>
>> --
>> 2.43.0
