On Tue, Aug 17, 2021 at 03:43:53PM +0900, Jeaho Hwang wrote: > If ctrl EP priming is failed (very rare case in standard linux), > hw_ep_set_halt goes infinite loop. waiting 100 times was enough > for zynq7000. > > Signed-off-by: Jeaho Hwang <jhhwang@xxxxxxxxxx> > > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c > index 8834ca613721..d73fadb18f32 100644 > --- a/drivers/usb/chipidea/udc.c > +++ b/drivers/usb/chipidea/udc.c > @@ -209,6 +209,9 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl) > return 0; > } > > +/* enough for zynq7000 evaluation board */ > +#define HW_EP_SET_HALT_COUNT_MAX 100 > + > /** > * hw_ep_set_halt: configures ep halt & resets data toggle after clear (execute > * without interruption) > @@ -221,6 +224,7 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl) > */ > static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value) > { > + int count = HW_EP_SET_HALT_COUNT_MAX; > if (value != 0 && value != 1) You need a blank line after "int count..." > return -EINVAL; > > @@ -232,9 +236,9 @@ static int hw_ep_set_halt(struct ci_hdrc *ci, int num, int dir, int value) > /* data toggle - reserved for EP0 but it's in ESS */ > hw_write(ci, reg, mask_xs|mask_xr, > value ? mask_xs : mask_xr); > - } while (value != hw_ep_get_halt(ci, num, dir)); > + } while (value != hw_ep_get_halt(ci, num, dir) && --count > 0); > > - return 0; > + return count ? 0 : -EAGAIN; Please spell this out: if (count) return 0; return -EAGAIN; And will the caller properly handle this? thanks, greg k-h