From c3727d61ea73a1df60bacd0b416e01282a94240b Mon Sep 17 00:00:00 2001 From: "Lendacky, Thomas" Date: Wed, 17 Feb 2016 11:49:16 -0600 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- 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); -- 2.7.4