[3.11.y.z extended stable] Patch "net: davinci_emac: Replace devm_request_irq with request_irq" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    net: davinci_emac: Replace devm_request_irq with request_irq

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From beaeeb8cb02b870ef1cce7f18c28ec9b6c66c3b6 Mon Sep 17 00:00:00 2001
From: Christian Riesch <christian.riesch at omicron.at>
Date: Mon, 24 Mar 2014 13:46:26 +0100
Subject: net: davinci_emac: Replace devm_request_irq with request_irq

commit 33b7107f59a61236d94ecd6b45e20283cd5abcc8 upstream.

In commit 6892b41d9701283085b655c6086fb57a5d63fa47

Author: Lad, Prabhakar <prabhakar.csengg at gmail.com>
Date:   Tue Jun 25 21:24:51 2013 +0530
net: davinci: emac: Convert to devm_* api

the call of request_irq is replaced by devm_request_irq and the call
of free_irq is removed. But since interrupts are requested in
emac_dev_open, doing ifconfig up/down on the board requests the
interrupts again each time, causing devm_request_irq to fail. The
interface is dead until the device is rebooted.

This patch reverts said commit partially: It changes the driver back
to use request_irq instead of devm_request_irq, puts free_irq back in
place, but keeps the remaining changes of the original patch.

Reported-by: Jon Ringle <jon at ringle.org>
Signed-off-by: Christian Riesch <christian.riesch at omicron.at>
Cc: Lad, Prabhakar <prabhakar.csengg at gmail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ethernet/ti/davinci_emac.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index 45c167f..b5a36315 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -1531,7 +1531,7 @@ static int emac_dev_open(struct net_device *ndev)
 	struct device *emac_dev = &ndev->dev;
 	u32 cnt;
 	struct resource *res;
-	int ret;
+	int q, m, ret;
 	int i = 0;
 	int k = 0;
 	struct emac_priv *priv = netdev_priv(ndev);
@@ -1566,8 +1566,7 @@ static int emac_dev_open(struct net_device *ndev)

 	while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k))) {
 		for (i = res->start; i <= res->end; i++) {
-			if (devm_request_irq(&priv->pdev->dev, i, emac_irq,
-					     0, ndev->name, ndev))
+			if (request_irq(i, emac_irq, 0, ndev->name, ndev))
 				goto rollback;
 		}
 		k++;
@@ -1640,7 +1639,15 @@ static int emac_dev_open(struct net_device *ndev)

 rollback:

-	dev_err(emac_dev, "DaVinci EMAC: devm_request_irq() failed");
+	dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");
+
+	for (q = k; k >= 0; k--) {
+		for (m = i; m >= res->start; m--)
+			free_irq(m, ndev);
+		res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1);
+		m = res->end;
+	}
+
 	ret = -EBUSY;
 err:
 	pm_runtime_put(&priv->pdev->dev);
@@ -1658,6 +1665,9 @@ err:
  */
 static int emac_dev_stop(struct net_device *ndev)
 {
+	struct resource *res;
+	int i = 0;
+	int irq_num;
 	struct emac_priv *priv = netdev_priv(ndev);
 	struct device *emac_dev = &ndev->dev;

@@ -1673,6 +1683,13 @@ static int emac_dev_stop(struct net_device *ndev)
 	if (priv->phydev)
 		phy_disconnect(priv->phydev);

+	/* Free IRQ */
+	while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, i))) {
+		for (irq_num = res->start; irq_num <= res->end; irq_num++)
+			free_irq(irq_num, priv->ndev);
+		i++;
+	}
+
 	if (netif_msg_drv(priv))
 		dev_notice(emac_dev, "DaVinci EMAC: %s stopped\n", ndev->name);

--
1.9.1