diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c index 533b17d58e45aa..73f76438e3f41b 100644 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c @@ -46,7 +46,7 @@ #include "dwc_otg_hcd.h" #include "dwc_otg_regs.h" -extern bool microframe_schedule; +extern bool microframe_schedule, nak_holdoff_enable; //#define DEBUG_HOST_CHANNELS #ifdef DEBUG_HOST_CHANNELS @@ -1349,18 +1349,26 @@ dwc_otg_transaction_type_e dwc_otg_hcd_select_transactions(dwc_otg_hcd_t * hcd) /* * Check to see if this is a NAK'd retransmit, in which case ignore for retransmission - * we hold off on bulk retransmissions to reduce NAK interrupt overhead for + * we hold off on bulk retransmissions to reduce NAK interrupt overhead for full-speed * cheeky devices that just hold off using NAKs */ - if (dwc_full_frame_num(qh->nak_frame) == dwc_full_frame_num(dwc_otg_hcd_get_frame_number(hcd))) { - // Make fiq interrupt run on next frame (i.e. 8 uframes) - g_next_sched_frame = ((qh->nak_frame + 8) & ~7) & DWC_HFNUM_MAX_FRNUM; - qh_ptr = DWC_LIST_NEXT(qh_ptr); - continue; + if (nak_holdoff_enable && qh->do_split) { + if (qh->nak_frame != 0xffff && + dwc_full_frame_num(qh->nak_frame) == + dwc_full_frame_num(dwc_otg_hcd_get_frame_number(hcd))) { + /* + * Revisit: Need to avoid trampling on periodic scheduling. + * Currently we are safe because g_np_count != g_np_sent whenever we hit this, + * but if this behaviour is changed then periodic endpoints will get a slower + * polling rate. + */ + g_next_sched_frame = ((qh->nak_frame + 8) & ~7) & DWC_HFNUM_MAX_FRNUM; + qh_ptr = DWC_LIST_NEXT(qh_ptr); + continue; + } else { + qh->nak_frame = 0xffff; + } } - else - qh->nak_frame = 0xffff; - if (microframe_schedule) { DWC_SPINLOCK_IRQSAVE(channel_lock, &flags); if (hcd->available_host_channels < 1) {