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path: root/drivers/net/ipa/ipa_modem.c
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Diffstat (limited to 'drivers/net/ipa/ipa_modem.c')
-rw-r--r--drivers/net/ipa/ipa_modem.c96
1 files changed, 61 insertions, 35 deletions
diff --git a/drivers/net/ipa/ipa_modem.c b/drivers/net/ipa/ipa_modem.c
index 423422a2a445..1d1be92fbebc 100644
--- a/drivers/net/ipa/ipa_modem.c
+++ b/drivers/net/ipa/ipa_modem.c
@@ -39,10 +39,14 @@ enum ipa_modem_state {
/**
* struct ipa_priv - IPA network device private data
* @ipa: IPA pointer
+ * @tx: Transmit endpoint pointer
+ * @rx: Receive endpoint pointer
* @work: Work structure used to wake the modem netdev TX queue
*/
struct ipa_priv {
struct ipa *ipa;
+ struct ipa_endpoint *tx;
+ struct ipa_endpoint *rx;
struct work_struct work;
};
@@ -59,11 +63,11 @@ static int ipa_open(struct net_device *netdev)
if (ret < 0)
goto err_power_put;
- ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
+ ret = ipa_endpoint_enable_one(priv->tx);
if (ret)
goto err_power_put;
- ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
+ ret = ipa_endpoint_enable_one(priv->rx);
if (ret)
goto err_disable_tx;
@@ -75,7 +79,7 @@ static int ipa_open(struct net_device *netdev)
return 0;
err_disable_tx:
- ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
+ ipa_endpoint_disable_one(priv->tx);
err_power_put:
pm_runtime_put_noidle(dev);
@@ -97,8 +101,8 @@ static int ipa_stop(struct net_device *netdev)
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]);
+ ipa_endpoint_disable_one(priv->rx);
+ ipa_endpoint_disable_one(priv->tx);
out_power_put:
pm_runtime_mark_last_busy(dev);
(void)pm_runtime_put_autosuspend(dev);
@@ -106,13 +110,16 @@ out_power_put:
return 0;
}
-/** ipa_start_xmit() - Transmits an skb.
- * @skb: skb to be transmitted
- * @dev: network device
+/** ipa_start_xmit() - Transmit an skb
+ * @skb: Socket buffer to be transmitted
+ * @netdev: Network device
*
- * Return codes:
- * NETDEV_TX_OK: Success
- * NETDEV_TX_BUSY: Error while transmitting the skb. Try again later
+ * Return: NETDEV_TX_OK if successful (or dropped), NETDEV_TX_BUSY otherwise
+
+ * Normally NETDEV_TX_OK indicates the buffer was successfully transmitted.
+ * If the buffer has an unexpected protocol or its size is out of range it
+ * is quietly dropped, returning NETDEV_TX_OK. NETDEV_TX_BUSY indicates
+ * the buffer cannot be sent at this time and should retried later.
*/
static netdev_tx_t
ipa_start_xmit(struct sk_buff *skb, struct net_device *netdev)
@@ -132,29 +139,41 @@ ipa_start_xmit(struct sk_buff *skb, struct net_device *netdev)
if (endpoint->config.qmap && skb->protocol != htons(ETH_P_MAP))
goto err_drop_skb;
- /* The hardware must be powered for us to transmit */
+ /* The hardware must be powered for us to transmit, so if we're not
+ * ready we want the network stack to stop queueing until power is
+ * ACTIVE. Once runtime resume has completed, we inform the network
+ * stack it's OK to try transmitting again.
+ *
+ * We learn from pm_runtime_get() whether the hardware is powered.
+ * If it was not, powering up is either started or already underway.
+ * And in that case we want to disable queueing, expecting it to be
+ * re-enabled once power is ACTIVE. But runtime PM and network
+ * transmit run concurrently, and if we're not careful the requests
+ * to stop and start queueing could occur in the wrong order.
+ *
+ * For that reason we *always* stop queueing here, *before* the call
+ * to pm_runtime_get(). If we determine here that power is ACTIVE,
+ * we restart queueing before transmitting the SKB. Otherwise
+ * queueing will eventually be enabled after resume completes.
+ */
+ netif_stop_queue(netdev);
+
dev = &ipa->pdev->dev;
ret = pm_runtime_get(dev);
if (ret < 1) {
/* If a resume won't happen, just drop the packet */
if (ret < 0 && ret != -EINPROGRESS) {
- ipa_power_modem_queue_active(ipa);
+ netif_wake_queue(netdev);
pm_runtime_put_noidle(dev);
goto err_drop_skb;
}
- /* No power (yet). Stop the network stack from transmitting
- * until we're resumed; ipa_modem_resume() arranges for the
- * TX queue to be started again.
- */
- ipa_power_modem_queue_stop(ipa);
-
pm_runtime_put_noidle(dev);
return NETDEV_TX_BUSY;
}
- ipa_power_modem_queue_active(ipa);
+ netif_wake_queue(netdev);
ret = ipa_endpoint_skb_tx(endpoint, skb);
@@ -233,14 +252,14 @@ static void ipa_modem_netdev_setup(struct net_device *netdev)
*/
void ipa_modem_suspend(struct net_device *netdev)
{
- struct ipa_priv *priv = netdev_priv(netdev);
- struct ipa *ipa = priv->ipa;
+ struct ipa_priv *priv;
if (!(netdev->flags & IFF_UP))
return;
- ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
- ipa_endpoint_suspend_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
+ priv = netdev_priv(netdev);
+ ipa_endpoint_suspend_one(priv->rx);
+ ipa_endpoint_suspend_one(priv->tx);
}
/**
@@ -258,7 +277,7 @@ static void ipa_modem_wake_queue_work(struct work_struct *work)
{
struct ipa_priv *priv = container_of(work, struct ipa_priv, work);
- ipa_power_modem_queue_wake(priv->ipa);
+ netif_wake_queue(priv->tx->netdev);
}
/** ipa_modem_resume() - resume callback for runtime_pm
@@ -268,14 +287,14 @@ static void ipa_modem_wake_queue_work(struct work_struct *work)
*/
void ipa_modem_resume(struct net_device *netdev)
{
- struct ipa_priv *priv = netdev_priv(netdev);
- struct ipa *ipa = priv->ipa;
+ struct ipa_priv *priv;
if (!(netdev->flags & IFF_UP))
return;
- ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
- ipa_endpoint_resume_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
+ priv = netdev_priv(netdev);
+ ipa_endpoint_resume_one(priv->tx);
+ ipa_endpoint_resume_one(priv->rx);
/* Arrange for the TX queue to be restarted */
(void)queue_pm_work(&priv->work);
@@ -306,16 +325,21 @@ int ipa_modem_start(struct ipa *ipa)
SET_NETDEV_DEV(netdev, &ipa->pdev->dev);
priv = netdev_priv(netdev);
priv->ipa = ipa;
+ priv->tx = ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX];
+ priv->rx = ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX];
INIT_WORK(&priv->work, ipa_modem_wake_queue_work);
- ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = netdev;
- ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = netdev;
+
+ priv->tx->netdev = netdev;
+ priv->rx->netdev = netdev;
+
ipa->modem_netdev = netdev;
ret = register_netdev(netdev);
if (ret) {
ipa->modem_netdev = NULL;
- ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
- ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = NULL;
+ priv->rx->netdev = NULL;
+ priv->tx->netdev = NULL;
+
free_netdev(netdev);
}
@@ -355,9 +379,11 @@ int ipa_modem_stop(struct ipa *ipa)
if (netdev->flags & IFF_UP)
(void)ipa_stop(netdev);
unregister_netdev(netdev);
+
ipa->modem_netdev = NULL;
- ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]->netdev = NULL;
- ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]->netdev = NULL;
+ priv->rx->netdev = NULL;
+ priv->tx->netdev = NULL;
+
free_netdev(netdev);
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-23 00:27:34 +0300