[U-Boot] [PATCH] usb: dwc2: Enhance interrupt handling for CONTROL transaction

[Chin Liang See]

Per DesignWare USB OTG databook, driver should retry up to
3 times when transaction error (hcint.xacterr) happen. But
the 3 times doesn't count when the response is nack
(hcint.nak) or frame overrun (hcint.frmoverun)

This patch solved the enumeration error as spotted at socfpga
cyclone5_socdk when plugging in certain pendrive.

Signed-off-by: Chin Liang See <clsee at altera.com>
Cc: Marek Vasut <marex at denx.de>
Cc: Dinh Nguyen <dinguyen at opensource.altera.com>
Cc: Dinh Nguyen <dinh.linux at gmail.com>
Cc: Pavel Machek <pavel at denx.de>
Cc: Oleksandr Tymoshenko <gonzo at bluezbox.com>
Cc: Stephen Warren <swarren at wwwdotorg.org>
Cc: Alexander Stein <alexanders83 at web.de>
Cc: Peter Griffin <peter.griffin at linaro.org>
---
 drivers/usb/host/dwc2.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
index 541c0f9..f00cd1b 100644
--- a/drivers/usb/host/dwc2.c
+++ b/drivers/usb/host/dwc2.c
@@ -786,15 +786,12 @@ int chunk_msg(struct dwc2_priv *priv, struct usb_device *dev,
 	uint32_t xfer_len;
 	uint32_t num_packets;
 	int stop_transfer = 0;
+	int error_retry_count = 0;
 
 	debug("%s: msg: pipe %lx pid %d in %d len %d\n", __func__, pipe, *pid,
 	      in, len);
 
 	do {
-		/* Initialize channel */
-		dwc_otg_hc_init(regs, DWC2_HC_CHANNEL, dev, devnum, ep, in,
-				eptype, max);
-
 		xfer_len = len - done;
 		if (xfer_len > CONFIG_DWC2_MAX_TRANSFER_SIZE)
 			xfer_len = CONFIG_DWC2_MAX_TRANSFER_SIZE - max + 1;
@@ -818,6 +815,14 @@ int chunk_msg(struct dwc2_priv *priv, struct usb_device *dev,
 		debug("%s: chunk: pid %d xfer_len %u pkts %u\n", __func__,
 		      *pid, xfer_len, num_packets);
 
+		/* per DW spec, we can retry up to 3 times */
+		error_retry_count = 3;
+
+error_retry:
+		/* Initialize channel */
+		dwc_otg_hc_init(regs, DWC2_HC_CHANNEL, dev, devnum, ep, in,
+				eptype, max);
+
 		writel((xfer_len << DWC2_HCTSIZ_XFERSIZE_OFFSET) |
 		       (num_packets << DWC2_HCTSIZ_PKTCNT_OFFSET) |
 		       (*pid << DWC2_HCTSIZ_PID_OFFSET),
@@ -841,8 +846,14 @@ int chunk_msg(struct dwc2_priv *priv, struct usb_device *dev,
 				DWC2_HCCHAR_CHEN);
 
 		ret = wait_for_chhltd(regs, &sub, pid, ignore_ack);
-		if (ret)
-			break;
+		if (ret) {
+			if (ret == -EINVAL)
+				error_retry_count--;
+			if (error_retry_count)
+				goto error_retry;
+			else
+				break;
+		}
 
 		if (in) {
 			xfer_len -= sub;
-- 
1.9.2.468.g3f0c02a