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Message-ID: <20160217174916.26246.99839.stgit@tlendack-t1.amdoffice.net>
Date: Wed, 17 Feb 2016 11:49:16 -0600
From: Tom Lendacky <thomas.lendacky@....com>
To: <netdev@...r.kernel.org>
CC: David Miller <davem@...emloft.net>
Subject: [PATCH net-next v2 8/9] amd-xgbe: Check Rx queue fifos before
stopping Rx DMA
Check to be sure that the Rx queue fifos are empty before stopping the
Rx DMA channels.
Signed-off-by: Tom Lendacky <thomas.lendacky@....com>
---
drivers/net/ethernet/amd/xgbe/xgbe-common.h | 10 ++++++---
drivers/net/ethernet/amd/xgbe/xgbe-dev.c | 30 +++++++++++++++++++++++++++
2 files changed, 37 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-common.h b/drivers/net/ethernet/amd/xgbe/xgbe-common.h
index b6fa891..bbef959 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-common.h
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-common.h
@@ -6,7 +6,7 @@
*
* License 1: GPLv2
*
- * Copyright (c) 2014 Advanced Micro Devices, Inc.
+ * Copyright (c) 2014-2016 Advanced Micro Devices, Inc.
*
* This file is free software; you may copy, redistribute and/or modify
* it under the terms of the GNU General Public License as published by
@@ -56,7 +56,7 @@
*
* License 2: Modified BSD
*
- * Copyright (c) 2014 Advanced Micro Devices, Inc.
+ * Copyright (c) 2014-2016 Advanced Micro Devices, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -768,12 +768,16 @@
#define MTL_Q_TQDR 0x08
#define MTL_Q_RQOMR 0x40
#define MTL_Q_RQMPOCR 0x44
-#define MTL_Q_RQDR 0x4c
+#define MTL_Q_RQDR 0x48
#define MTL_Q_RQFCR 0x50
#define MTL_Q_IER 0x70
#define MTL_Q_ISR 0x74
/* MTL queue register entry bit positions and sizes */
+#define MTL_Q_RQDR_PRXQ_INDEX 16
+#define MTL_Q_RQDR_PRXQ_WIDTH 14
+#define MTL_Q_RQDR_RXQSTS_INDEX 4
+#define MTL_Q_RQDR_RXQSTS_WIDTH 2
#define MTL_Q_RQFCR_RFA_INDEX 1
#define MTL_Q_RQFCR_RFA_WIDTH 6
#define MTL_Q_RQFCR_RFD_INDEX 17
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
index 43273c98..b48c6ec 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
@@ -2656,6 +2656,32 @@ static void xgbe_disable_tx(struct xgbe_prv_data *pdata)
}
}
+static void xgbe_prepare_rx_stop(struct xgbe_prv_data *pdata,
+ unsigned int queue)
+{
+ unsigned int rx_status;
+ unsigned long rx_timeout;
+
+ /* The Rx engine cannot be stopped if it is actively processing
+ * packets. Wait for the Rx queue to empty the Rx fifo. Don't
+ * wait forever though...
+ */
+ rx_timeout = jiffies + (XGBE_DMA_STOP_TIMEOUT * HZ);
+ while (time_before(jiffies, rx_timeout)) {
+ rx_status = XGMAC_MTL_IOREAD(pdata, queue, MTL_Q_RQDR);
+ if ((XGMAC_GET_BITS(rx_status, MTL_Q_RQDR, PRXQ) == 0) &&
+ (XGMAC_GET_BITS(rx_status, MTL_Q_RQDR, RXQSTS) == 0))
+ break;
+
+ usleep_range(500, 1000);
+ }
+
+ if (!time_before(jiffies, rx_timeout))
+ netdev_info(pdata->netdev,
+ "timed out waiting for Rx queue %u to empty\n",
+ queue);
+}
+
static void xgbe_enable_rx(struct xgbe_prv_data *pdata)
{
struct xgbe_channel *channel;
@@ -2694,6 +2720,10 @@ static void xgbe_disable_rx(struct xgbe_prv_data *pdata)
XGMAC_IOWRITE_BITS(pdata, MAC_RCR, ACS, 0);
XGMAC_IOWRITE_BITS(pdata, MAC_RCR, RE, 0);
+ /* Prepare for Rx DMA channel stop */
+ for (i = 0; i < pdata->rx_q_count; i++)
+ xgbe_prepare_rx_stop(pdata, i);
+
/* Disable each Rx queue */
XGMAC_IOWRITE(pdata, MAC_RQC0R, 0);
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