[PATCH 4.4 50/53] net/sonic: Quiesce SONIC before re-initializing descriptor memory

Greg Kroah-Hartman
2020-02-03T16:21:38Z

From: Finn Thain <fthain@telegraphics.com.au>

[ Upstream commit 3f4b7e6a2be982fd8820a2b54d46dd9c351db899 ]

Make sure the SONIC's DMA engine is idle before altering the transmit
and receive descriptors. Add a helper for this as it will be needed
again.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/natsemi/sonic.c | 25 +++++++++++++++++++++++++
drivers/net/ethernet/natsemi/sonic.h | 3 +++
2 files changed, 28 insertions(+)

diff --git a/drivers/net/ethernet/natsemi/sonic.c b/drivers/net/ethernet/natsemi/sonic.c
index 21766ec12ef20..712be59251f51 100644
--- a/drivers/net/ethernet/natsemi/sonic.c
+++ b/drivers/net/ethernet/natsemi/sonic.c
@@ -103,6 +103,24 @@ static int sonic_open(struct net_device *dev)
return 0;
}

+/* Wait for the SONIC to become idle. */
+static void sonic_quiesce(struct net_device *dev, u16 mask)
+{
+ struct sonic_local * __maybe_unused lp = netdev_priv(dev);
+ int i;
+ u16 bits;
+
+ for (i = 0; i < 1000; ++i) {
+ bits = SONIC_READ(SONIC_CMD) & mask;
+ if (!bits)
+ return;
+ if (irqs_disabled() || in_interrupt())
+ udelay(20);
+ else
+ usleep_range(100, 200);
+ }
+ WARN_ONCE(1, "command deadline expired! 0x%04x\n", bits);
+}

/*
* Close the SONIC device
@@ -120,6 +138,9 @@ static int sonic_close(struct net_device *dev)
/*
* stop the SONIC, disable interrupts
*/
+ SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
+ sonic_quiesce(dev, SONIC_CR_ALL);
+
SONIC_WRITE(SONIC_IMR, 0);
SONIC_WRITE(SONIC_ISR, 0x7fff);
SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
@@ -159,6 +180,9 @@ static void sonic_tx_timeout(struct net_device *dev)
* put the Sonic into software-reset mode and
* disable all interrupts before releasing DMA buffers
*/
+ SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
+ sonic_quiesce(dev, SONIC_CR_ALL);
+
SONIC_WRITE(SONIC_IMR, 0);
SONIC_WRITE(SONIC_ISR, 0x7fff);
SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
@@ -638,6 +662,7 @@ static int sonic_init(struct net_device *dev)
*/
SONIC_WRITE(SONIC_CMD, 0);
SONIC_WRITE(SONIC_CMD, SONIC_CR_RXDIS);
+ sonic_quiesce(dev, SONIC_CR_ALL);

/*
* initialize the receive resource area
diff --git a/drivers/net/ethernet/natsemi/sonic.h b/drivers/net/ethernet/natsemi/sonic.h
index d9f8ceb5353a4..7dcf913d7395a 100644
--- a/drivers/net/ethernet/natsemi/sonic.h
+++ b/drivers/net/ethernet/natsemi/sonic.h
@@ -109,6 +109,9 @@
#define SONIC_CR_TXP 0x0002
#define SONIC_CR_HTX 0x0001

+#define SONIC_CR_ALL (SONIC_CR_LCAM | SONIC_CR_RRRA | \
+ SONIC_CR_RXEN | SONIC_CR_TXP)
+
/*
* SONIC data configuration bits
*/
--
2.20.1