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[net-next,v2,3/3] epic100: allow nesting of ethtool_ops begin() and complete()

Message ID 4d6d90454847364e49b104caf5736493170f2bea.1578292157.git.mkubecek@suse.cz (mailing list archive)
State Not Applicable
Delegated to: Johannes Berg
Headers show
Series ethtool: allow nesting of begin() and complete() callbacks | expand

Commit Message

Michal Kubecek Jan. 6, 2020, 6:39 a.m. UTC
Unlike most networking drivers using begin() and complete() ethtool_ops
callbacks to resume a device which is down and suspend it again when done,
epic100 does not use standard refcounted infrastructure but sets device
sleep state directly.

With the introduction of netlink ethtool interface, we may have nested
begin-complete blocks so that inner complete() would put the device back to
sleep for the rest of the outer block.

To avoid rewriting an old and not very actively developed driver, just add
a nesting counter and only perform resume and suspend on the outermost
level.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
---
v2: fix inverted condition in ethtool_begin() (thanks to Andrew Lunn)
---
 drivers/net/ethernet/smsc/epic100.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/smsc/epic100.c b/drivers/net/ethernet/smsc/epic100.c
index 912760e8514c..61ddee0c2a2e 100644
--- a/drivers/net/ethernet/smsc/epic100.c
+++ b/drivers/net/ethernet/smsc/epic100.c
@@ -280,6 +280,7 @@  struct epic_private {
 	signed char phys[4];				/* MII device addresses. */
 	u16 advertising;					/* NWay media advertisement */
 	int mii_phy_cnt;
+	u32 ethtool_ops_nesting;
 	struct mii_if_info mii;
 	unsigned int tx_full:1;				/* The Tx queue is full. */
 	unsigned int default_port:4;		/* Last dev->if_port value. */
@@ -1435,8 +1436,10 @@  static int ethtool_begin(struct net_device *dev)
 	struct epic_private *ep = netdev_priv(dev);
 	void __iomem *ioaddr = ep->ioaddr;
 
+	if (ep->ethtool_ops_nesting == U32_MAX)
+		return -EBUSY;
 	/* power-up, if interface is down */
-	if (!netif_running(dev)) {
+	if (!ep->ethtool_ops_nesting++ && !netif_running(dev)) {
 		ew32(GENCTL, 0x0200);
 		ew32(NVCTL, (er32(NVCTL) & ~0x003c) | 0x4800);
 	}
@@ -1449,7 +1452,7 @@  static void ethtool_complete(struct net_device *dev)
 	void __iomem *ioaddr = ep->ioaddr;
 
 	/* power-down, if interface is down */
-	if (!netif_running(dev)) {
+	if (!--ep->ethtool_ops_nesting && !netif_running(dev)) {
 		ew32(GENCTL, 0x0008);
 		ew32(NVCTL, (er32(NVCTL) & ~0x483c) | 0x0000);
 	}