[PATCH net 3/4] net: bcmgenet: let the interface be reopened after a failed resume

[Nicolai Buchwitz]

bcmgenet_suspend() detaches the device and a resume that fails in
bcmgenet_init_dma() never attaches it again, so an ifdown and ifup cannot
bring the interface back:

  # ip link set eth0 up
  RTNETLINK answers: No such device

That resume also gates the clock and powers the block down before it
returns. Close and the next suspend_noirq then release a clock that is
already released, which the clock core warns about. Leave the hardware as
bcmgenet_resume_noirq() set it up, so the clock stays on while the
interface is up and close or suspend releases it once.

Attach again in close, where __dev_close_many() has already cleared
__LINK_STATE_START, so no queue is woken.

Fixes: b6e978e50444 ("net: bcmgenet: add suspend/resume callbacks")
Signed-off-by: Nicolai Buchwitz <nb@xxxxxxxxxxx>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index fe3338ba81980..cb9951d6036fb 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -3508,6 +3508,9 @@ static int bcmgenet_close(struct net_device *dev)
 	free_irq(priv->irq0, priv);
 	free_irq(priv->irq1, priv);
 
+	/* A failed resume left the device detached, __dev_open() refuses that */
+	netif_device_attach(dev);
+
 	if (priv->internal_phy)
 		ret = bcmgenet_power_down(priv, GENET_POWER_PASSIVE);
 
@@ -4324,8 +4327,9 @@ static int bcmgenet_resume(struct device *d)
 	/* Reinitialize TDMA and RDMA and SW housekeeping */
 	ret = bcmgenet_init_dma(priv, false);
 	if (ret) {
+		/* Leave the block clocked, close and suspend tear it down */
 		netdev_err(dev, "failed to initialize DMA\n");
-		goto out_clk_disable;
+		return ret;
 	}
 
 	if (!device_may_wakeup(d))
@@ -4336,12 +4340,6 @@ static int bcmgenet_resume(struct device *d)
 	netif_device_attach(dev);
 
 	return 0;
-
-out_clk_disable:
-	if (priv->internal_phy)
-		bcmgenet_power_down(priv, GENET_POWER_PASSIVE);
-	clk_disable_unprepare(priv->clk);
-	return ret;
 }
 
 static int bcmgenet_suspend(struct device *d)

-- 
2.53.0