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@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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_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 @@
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);