[PATCH net-next 6/6] net: ipa: don't hold clock reference while netdev open

From: Alex Elder
Date: Thu Aug 12 2021 - 15:51:01 EST


Currently a clock reference is taken whenever the ->ndo_open
callback for the modem netdev is called. That reference is dropped
when the device is closed, in ipa_stop().

We no longer need this, because ipa_start_xmit() now handles the
situation where the hardware power state is not active.

Drop the clock reference in ipa_open() when we're done, and take a
new reference in ipa_stop() before we begin closing the interface.

Finally (and unrelated, but trivial), change the return type of
ipa_start_xmit() to be netdev_tx_t instead of int.

Signed-off-by: Alex Elder <elder@xxxxxxxxxx>
---
drivers/net/ipa/ipa_modem.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ipa/ipa_modem.c b/drivers/net/ipa/ipa_modem.c
index b176910d72868..c8724af935b85 100644
--- a/drivers/net/ipa/ipa_modem.c
+++ b/drivers/net/ipa/ipa_modem.c
@@ -65,6 +65,8 @@ static int ipa_open(struct net_device *netdev)

netif_start_queue(netdev);

+ (void)ipa_clock_put(ipa);
+
return 0;

err_disable_tx:
@@ -80,12 +82,17 @@ static int ipa_stop(struct net_device *netdev)
{
struct ipa_priv *priv = netdev_priv(netdev);
struct ipa *ipa = priv->ipa;
+ int ret;
+
+ ret = ipa_clock_get(ipa);
+ if (WARN_ON(ret < 0))
+ goto out_clock_put;

netif_stop_queue(netdev);

ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
-
+out_clock_put:
(void)ipa_clock_put(ipa);

return 0;
@@ -99,7 +106,8 @@ static int ipa_stop(struct net_device *netdev)
* NETDEV_TX_OK: Success
* NETDEV_TX_BUSY: Error while transmitting the skb. Try again later
*/
-static int ipa_start_xmit(struct sk_buff *skb, struct net_device *netdev)
+static netdev_tx_t
+ipa_start_xmit(struct sk_buff *skb, struct net_device *netdev)
{
struct net_device_stats *stats = &netdev->stats;
struct ipa_priv *priv = netdev_priv(netdev);
--
2.27.0