usb: dwc2: gadget: ISOC's starting flow improvement

[Felipe Balbi <balbi@kernel.org>]

Minas Harutyunyan <Minas.Harutyunyan@synopsys.com> writes:

> To start ISOC transfers in handlers dwc2_gadget_handle_nak() and
> dwc2_gadget_handle_out_token_ep_disabled() driver reads current frame
> number, based on which, set target frame number to start first ISOC
> transfer.
>
> In case if system's high IRQ latency and multiple EP's asserted
> interrupt in same frame, there are high probability that when reading
> current frame number in EP's handlers, actual frame number can be
> increased. As result for bInterval > 1, starting target frame
> will be set wrongly and all ISOC packets will be dropped.
>
> In patch "usb: dwc2: Change reading of current frame number flow"
> reading of current frame number done ASAP in common interrupt handler.
> This frame number stored in frame_number variable which used as
> starting frame number for ISOC EP's in above mentioned handlers.
>
> Signed-off-by: Minas Harutyunyan <hminas@synopsys.com>

please rebase on top of testing/next after a couple hours:

checking file drivers/usb/dwc2/gadget.c
Hunk #1 FAILED at 2749.
Hunk #2 succeeded at 2772 (offset -1 lines).
Hunk #3 FAILED at 2811.
2 out of 3 hunks FAILED