From: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Date: Wed, 4 Jun 2014 22:28:49 +0000 (-0500)
Subject: dm9000: avoid sleeping in dm9000_timeout callback
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=582379839bbdb76f2f0ad956a39f920cfd84fcea;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

dm9000: avoid sleeping in dm9000_timeout callback

On the DM9000B, dm9000_msleep() is called during the dm9000_timeout()
routine.  Since dm9000_timeout() holds the main spinlock through the
entire routine, mdelay() needs to be used rather than msleep().
Furthermore, the mutex_lock()/mutex_unlock() should be avoided so as to
not sleep with spinlocks held.

Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ethernet/davicom/dm9000.c b/drivers/net/ethernet/davicom/dm9000.c
index 48870a8b39a4..13723c96d1a2 100644
--- a/drivers/net/ethernet/davicom/dm9000.c
+++ b/drivers/net/ethernet/davicom/dm9000.c
@@ -109,6 +109,7 @@ typedef struct board_info {
 	u8		imr_all;
 
 	unsigned int	flags;
+	unsigned int	in_timeout:1;
 	unsigned int	in_suspend:1;
 	unsigned int	wake_supported:1;
 
@@ -273,7 +274,7 @@ static void dm9000_dumpblk_32bit(void __iomem *reg, int count)
  */
 static void dm9000_msleep(board_info_t *db, unsigned int ms)
 {
-	if (db->in_suspend)
+	if (db->in_suspend || db->in_timeout)
 		mdelay(ms);
 	else
 		msleep(ms);
@@ -334,7 +335,8 @@ dm9000_phy_write(struct net_device *dev,
 	unsigned long reg_save;
 
 	dm9000_dbg(db, 5, "phy_write[%02x] = %04x\n", reg, value);
-	mutex_lock(&db->addr_lock);
+	if (!db->in_timeout)
+		mutex_lock(&db->addr_lock);
 
 	spin_lock_irqsave(&db->lock, flags);
 
@@ -365,7 +367,8 @@ dm9000_phy_write(struct net_device *dev,
 	writeb(reg_save, db->io_addr);
 
 	spin_unlock_irqrestore(&db->lock, flags);
-	mutex_unlock(&db->addr_lock);
+	if (!db->in_timeout)
+		mutex_unlock(&db->addr_lock);
 }
 
 /* dm9000_set_io
@@ -971,6 +974,7 @@ static void dm9000_timeout(struct net_device *dev)
 
 	/* Save previous register address */
 	spin_lock_irqsave(&db->lock, flags);
+	db->in_timeout = 1;
 	reg_save = readb(db->io_addr);
 
 	netif_stop_queue(dev);
@@ -982,6 +986,7 @@ static void dm9000_timeout(struct net_device *dev)
 
 	/* Restore previous register address */
 	writeb(reg_save, db->io_addr);
+	db->in_timeout = 0;
 	spin_unlock_irqrestore(&db->lock, flags);
 }