1 From 2fb3834b3ce43c6320c8186795b86ffa2257bd21 Mon Sep 17 00:00:00 2001
2 From: P33M <P33M@github.com>
3 Date: Fri, 20 Sep 2013 16:08:27 +0100
4 Subject: [PATCH 093/196] dwc_otg: Enable NAK holdoff for control split
7 Certain low-speed devices take a very long time to complete a
8 data or status stage of a control transaction, producing NAK
9 responses until they complete internal processing - the USB2.0
10 spec limit is up to 500mS. This causes the same type of interrupt
11 storm as seen with USB-serial dongles prior to c8edb238.
13 In certain circumstances, usually while booting, this interrupt
14 storm could cause SD card timeouts.
16 drivers/usb/host/dwc_otg/dwc_otg_hcd_intr.c | 3 +--
17 1 file changed, 1 insertion(+), 2 deletions(-)
19 diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd_intr.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd_intr.c
20 index 19abea0..509b629 100644
21 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd_intr.c
22 +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd_intr.c
23 @@ -1857,8 +1857,7 @@ static int32_t handle_hc_nak_intr(dwc_otg_hcd_t * hcd,
25 switch(dwc_otg_hcd_get_pipe_type(&qtd->urb->pipe_info)) {
27 - //case UE_INTERRUPT:
30 if (nak_holdoff_enable)
31 hc->qh->nak_frame = dwc_otg_hcd_get_frame_number(hcd);