From 3d8a3a5cbcd4d36768cf53e778d8165aefabd5b0 Mon Sep 17 00:00:00 2001 From: P33M Date: Fri, 20 Sep 2013 16:08:27 +0100 Subject: [PATCH 093/174] dwc_otg: Enable NAK holdoff for control split transactions Certain low-speed devices take a very long time to complete a data or status stage of a control transaction, producing NAK responses until they complete internal processing - the USB2.0 spec limit is up to 500mS. This causes the same type of interrupt storm as seen with USB-serial dongles prior to c8edb238. In certain circumstances, usually while booting, this interrupt storm could cause SD card timeouts. --- drivers/usb/host/dwc_otg/dwc_otg_hcd_intr.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd_intr.c +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd_intr.c @@ -1857,8 +1857,7 @@ static int32_t handle_hc_nak_intr(dwc_ot */ switch(dwc_otg_hcd_get_pipe_type(&qtd->urb->pipe_info)) { case UE_BULK: - //case UE_INTERRUPT: - //case UE_CONTROL: + case UE_CONTROL: if (nak_holdoff_enable) hc->qh->nak_frame = dwc_otg_hcd_get_frame_number(hcd); }