Merge branch 'ipa-clock-refs'

Alex Elder says:

====================
net: ipa: add clock references

This series continues preparation for implementing runtime power
management for IPA.  We need to ensure that the IPA core clock and
interconnects are operational whenever IPA hardware is accessed.
And in particular this means that any external entry point that can
lead to accessing IPA hardware must guarantee the hardware is "up"
when it is accessed.

The first four patches in this series take IPA clock references when
needed by such external entry points, dropping those references in
those same functions when they are no longer required.

The last patch is a bit different, though it too prepares for
enabling runtime power management.  It avoids suspending/resuming
endpoints if setup is not complete.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 44 insertions, 12 deletions

diff --git a/drivers/net/ipa/ipa_main.c b/drivers/net/ipa/ipa_main.c
index 5bcc6cd13a9a..2e728d4914c8 100644
--- a/drivers/net/ipa/ipa_main.c
+++ b/drivers/net/ipa/ipa_main.c
@@ -194,6 +194,9 @@ static void ipa_teardown(struct ipa *ipa)
 	struct ipa_endpoint *exception_endpoint;
 	struct ipa_endpoint *command_endpoint;
 
+	/* We're going to tear everything down, as if setup never completed */
+	ipa->setup_complete = false;
+
 	ipa_qmi_teardown(ipa);
 	ipa_endpoint_default_route_clear(ipa);
 	exception_endpoint = ipa->name_map[IPA_ENDPOINT_AP_LAN_RX];
@@ -770,9 +773,12 @@ static int ipa_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_table_exit;
 
+	/* The clock needs to be active for config and setup */
+	ipa_clock_get(ipa);
+
 	ret = ipa_config(ipa, data);
 	if (ret)
-		goto err_modem_exit;
+		goto err_clock_put;	/* Error */
 
 	dev_info(dev, "IPA driver initialized");
 
@@ -781,7 +787,7 @@ static int ipa_probe(struct platform_device *pdev)
 	 * we're done here.
 	 */
 	if (modem_init)
-		return 0;
+		goto out_clock_put;	/* Done; no error */
 
 	/* Otherwise we need to load the firmware and have Trust Zone validate
 	 * and install it.  If that succeeds we can proceed with setup.
@@ -794,11 +800,15 @@ static int ipa_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_deconfig;
 
+out_clock_put:
+	ipa_clock_put(ipa);
+
 	return 0;
 
 err_deconfig:
 	ipa_deconfig(ipa);
-err_modem_exit:
+err_clock_put:
+	ipa_clock_put(ipa);
 	ipa_modem_exit(ipa);
 err_table_exit:
 	ipa_table_exit(ipa);
@@ -824,6 +834,8 @@ static int ipa_remove(struct platform_device *pdev)
 	struct ipa_clock *clock = ipa->clock;
 	int ret;
 
+	ipa_clock_get(ipa);
+
 	if (ipa->setup_complete) {
 		ret = ipa_modem_stop(ipa);
 		/* If starting or stopping is in progress, try once more */
@@ -838,6 +850,9 @@ static int ipa_remove(struct platform_device *pdev)
 	}
 
 	ipa_deconfig(ipa);
+
+	ipa_clock_put(ipa);
+
 	ipa_modem_exit(ipa);
 	ipa_table_exit(ipa);
 	ipa_endpoint_exit(ipa);
@@ -873,13 +888,11 @@ static int ipa_suspend(struct device *dev)
 {
 	struct ipa *ipa = dev_get_drvdata(dev);
 
-	/* When a suspended RX endpoint has a packet ready to receive, we
-	 * get an IPA SUSPEND interrupt.  We trigger a system resume in
-	 * that case, but only on the first such interrupt since suspend.
-	 */
-	__clear_bit(IPA_FLAG_RESUMED, ipa->flags);
-
-	ipa_endpoint_suspend(ipa);
+	/* Endpoints aren't usable until setup is complete */
+	if (ipa->setup_complete) {
+		__clear_bit(IPA_FLAG_RESUMED, ipa->flags);
+		ipa_endpoint_suspend(ipa);
+	}
 
 	ipa_clock_put(ipa);
 
@@ -905,7 +918,9 @@ static int ipa_resume(struct device *dev)
 	 */
 	ipa_clock_get(ipa);
 
-	ipa_endpoint_resume(ipa);
+	/* Endpoints aren't usable until setup is complete */
+	if (ipa->setup_complete)
+		ipa_endpoint_resume(ipa);
 
 	return 0;
 }
diff --git a/drivers/net/ipa/ipa_modem.c b/drivers/net/ipa/ipa_modem.c
index c851e2cf1255..4ea8287e9d23 100644
--- a/drivers/net/ipa/ipa_modem.c
+++ b/drivers/net/ipa/ipa_modem.c
@@ -20,6 +20,7 @@
 #include "ipa_smp2p.h"
 #include "ipa_qmi.h"
 #include "ipa_uc.h"
+#include "ipa_clock.h"
 
 #define IPA_NETDEV_NAME		"rmnet_ipa%d"
 #define IPA_NETDEV_TAILROOM	0	/* for padding by mux layer */
@@ -44,9 +45,12 @@ static int ipa_open(struct net_device *netdev)
 	struct ipa *ipa = priv->ipa;
 	int ret;
 
+	ipa_clock_get(ipa);
+
 	ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
 	if (ret)
-		return ret;
+		goto err_clock_put;
+
 	ret = ipa_endpoint_enable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_RX]);
 	if (ret)
 		goto err_disable_tx;
@@ -57,6 +61,8 @@ static int ipa_open(struct net_device *netdev)
 
 err_disable_tx:
 	ipa_endpoint_disable_one(ipa->name_map[IPA_ENDPOINT_AP_MODEM_TX]);
+err_clock_put:
+	ipa_clock_put(ipa);
 
 	return ret;
 }
@@ -72,6 +78,8 @@ static int ipa_stop(struct net_device *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_clock_put(ipa);
+
 	return 0;
 }
 
@@ -279,6 +287,8 @@ static void ipa_modem_crashed(struct ipa *ipa)
 	struct device *dev = &ipa->pdev->dev;
 	int ret;
 
+	ipa_clock_get(ipa);
+
 	ipa_endpoint_modem_pause_all(ipa, true);
 
 	ipa_endpoint_modem_hol_block_clear_all(ipa);
@@ -303,6 +313,8 @@ static void ipa_modem_crashed(struct ipa *ipa)
 	ret = ipa_mem_zero_modem(ipa);
 	if (ret)
 		dev_err(dev, "error %d zeroing modem memory regions\n", ret);
+
+	ipa_clock_put(ipa);
 }
 
 static int ipa_modem_notify(struct notifier_block *nb, unsigned long action,
diff --git a/drivers/net/ipa/ipa_smp2p.c b/drivers/net/ipa/ipa_smp2p.c
index 93270e50b6b3..0d15438a79e2 100644
--- a/drivers/net/ipa/ipa_smp2p.c
+++ b/drivers/net/ipa/ipa_smp2p.c
@@ -156,11 +156,16 @@ static irqreturn_t ipa_smp2p_modem_setup_ready_isr(int irq, void *dev_id)
 	if (!smp2p->disabled) {
 		int ret;
 
+		/* The clock needs to be active for setup */
+		ipa_clock_get(smp2p->ipa);
+
 		ret = ipa_setup(smp2p->ipa);
 		if (ret)
 			dev_err(&smp2p->ipa->pdev->dev,
 				"error %d from ipa_setup()\n", ret);
 		smp2p->disabled = true;
+
+		ipa_clock_put(smp2p->ipa);
 	}
 
 	mutex_unlock(&smp2p->mutex);