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tg3: Override clock, link aware and link idle mode during NVRAM dump

PATCH In review Prashant Sreedharan 2 participants 3 messages May 23, 2014 – May 24, 2014

Subsystems (3)
Networking Network drivers Broadcom TG3 gigabit Ethernet driver
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Prashant Sreedharan

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#0 lore raw

PATCH 1/1 tg3: Override clock, link aware and link idle mode during NVRAM dump

When cable is not present the clock speed of some of the devices is reduced based upon power saving mode setting in NVRAM. Due to this NVRAM reads take long time to complete as a result CPU soft lockup message is seen. Fix is to override clock, disable link aware and link idle modes before NVRAM reads and restore them back after the reads are complete. During this period also check if the thread needs to be rescheduled and if there are any signals to handle.

Also decrease the NVRAM command execution timeout value to 1ms.

Signed-off-by Prashant Sreedharan <[email protected]>
Signed-off-by Michael Chan <[email protected]>
---
 drivers/net/ethernet/broadcom/tg3.c |   44 +++++++++++++++++++++++++++++-----
 1 files changed, 37 insertions(+), 7 deletions(-)
drivers/net/ethernet/broadcom/tg3.c +37 -7
index ccd9015..c59e938 100644
@@ -3224,7 +3224,7 @@ static int tg3_nvram_read_using_eeprom(struct tg3 *tp,
 	return 0;
 }
 
-#define NVRAM_CMD_TIMEOUT 10000
+#define NVRAM_CMD_TIMEOUT 100
 
 static int tg3_nvram_exec_cmd(struct tg3 *tp, u32 nvram_cmd)
 {

@@ -11893,9 +11893,9 @@ static int tg3_get_eeprom_len(struct net_device *dev)
 static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom, u8 *data)
 {
 	struct tg3 *tp = netdev_priv(dev);
-	int ret;
+	int ret, cpmu_restore = 0;
 	u8  *pd;
-	u32 i, offset, len, b_offset, b_count;
+	u32 i, offset, len, b_offset, b_count, cpmu_val = 0;
 	__be32 val;
 
 	if (tg3_flag(tp, NO_NVRAM))

@@ -11907,6 +11907,20 @@ static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom,
 
 	eeprom->magic = TG3_EEPROM_MAGIC;
 
+	/* Override clock, link aware and link idle modes */
+	if (tg3_flag(tp, CPMU_PRESENT)) {
+		cpmu_val = tr32(TG3_CPMU_CTRL);
+		if (cpmu_val & (CPMU_CTRL_LINK_AWARE_MODE |
+				CPMU_CTRL_LINK_IDLE_MODE)) {
+
+			tw32(TG3_CPMU_CTRL, cpmu_val &
+			     ~(CPMU_CTRL_LINK_AWARE_MODE |
+			       CPMU_CTRL_LINK_IDLE_MODE));
+			cpmu_restore = 1;
+		}
+	}
+	tg3_override_clk(tp);
+
 	if (offset & 3) {
 		/* adjustments to start on required 4 byte boundary */
 		b_offset = offset & 3;

@@ -11917,7 +11931,7 @@ static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom,
 		}
 		ret = tg3_nvram_read_be32(tp, offset-b_offset, &val);
 		if (ret)
-			return ret;
+			goto eeprom_done;
 		memcpy(data, ((char *)&val) + b_offset, b_count);
 		len -= b_count;
 		offset += b_count;

@@ -11927,10 +11941,18 @@ static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom,
 	/* read bytes up to the last 4 byte boundary */
 	pd = &data[eeprom->len];
 	for (i = 0; i < (len - (len & 3)); i += 4) {
+		if (need_resched()) {
+			if (signal_pending(current)) {
+				eeprom->len += i;
+				ret = -EINTR;
+				goto eeprom_done;
+			}
+			cond_resched();
+		}
 		ret = tg3_nvram_read_be32(tp, offset + i, &val);
 		if (ret) {
 			eeprom->len += i;
-			return ret;
+			goto eeprom_done;
 		}
 		memcpy(pd + i, &val, 4);
 	}

@@ -11943,11 +11965,19 @@ static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom,
 		b_offset = offset + len - b_count;
 		ret = tg3_nvram_read_be32(tp, b_offset, &val);
 		if (ret)
-			return ret;
+			goto eeprom_done;
 		memcpy(pd, &val, b_count);
 		eeprom->len += b_count;
 	}
-	return 0;
+	ret = 0;
+
+eeprom_done:
+	/* Restore clock, link aware and link idle modes */
+	tg3_restore_clk(tp);
+	if (cpmu_restore)
+		tw32(TG3_CPMU_CTRL, cpmu_val);
+
+	return ret;
 }
 
 static int tg3_set_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom, u8 *data)
Signature · 1 line
1.7.1
maintainer
#1 lore raw

From: Prashant Sreedharan <[email protected]>
Date: Fri, 23 May 2014 09:54:44 -0700

drivers/net/ethernet/broadcom/tg3.c static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom, · line 11915

Quoted 3 lines
drivers/net/ethernet/broadcom/tg3.c +3 -0
+		if (cpmu_val & (CPMU_CTRL_LINK_AWARE_MODE |
+				CPMU_CTRL_LINK_IDLE_MODE)) {
+

Please remove this empty line.

drivers/net/ethernet/broadcom/tg3.c static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom, · line 11918

Quoted 3 lines
drivers/net/ethernet/broadcom/tg3.c +3 -0
+			tw32(TG3_CPMU_CTRL, cpmu_val &
+			     ~(CPMU_CTRL_LINK_AWARE_MODE |
+			       CPMU_CTRL_LINK_IDLE_MODE));

This is not indented correctly.

The ~() expression is part of the "cpum_val &", it's not another separate argument to tw32().

Therefore ~() should be indented to the column cpum_val starts at.

drivers/net/ethernet/broadcom/tg3.c static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom, · line 11948

Quoted 5 lines
drivers/net/ethernet/broadcom/tg3.c +5 -0
+		if (need_resched()) {
+			if (signal_pending(current)) {
+				eeprom->len += i;
+				ret = -EINTR;
+				goto eeprom_done;

Why are you incrementing eeprom->len when you break out of the loop due to a signal? You didn't read that extra byte.

author
#2 lore raw
Quoted 8 lines · David Miller

From: Prashant Sreedharan <[email protected]>
Date: Fri, 23 May 2014 09:54:44 -0700

drivers/net/ethernet/broadcom/tg3.c static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom, · line 11915

Quoted 3 lines
drivers/net/ethernet/broadcom/tg3.c +3 -0
+		if (cpmu_val & (CPMU_CTRL_LINK_AWARE_MODE |
+				CPMU_CTRL_LINK_IDLE_MODE)) {
+

Please remove this empty line.

Ok

Quoted 7 lines

drivers/net/ethernet/broadcom/tg3.c static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom, · line 11918

Quoted 4 lines
drivers/net/ethernet/broadcom/tg3.c +3 -0
+			tw32(TG3_CPMU_CTRL, cpmu_val &
+			     ~(CPMU_CTRL_LINK_AWARE_MODE |
+			       CPMU_CTRL_LINK_IDLE_MODE));

This is not indented correctly.

Quoted 6 lines

The ~() expression is part of the "cpum_val &", it's not another separate argument to tw32().

Therefore ~() should be indented to the column cpum_val starts at.

Will fix indentation.

Quoted 9 lines

drivers/net/ethernet/broadcom/tg3.c static int tg3_get_eeprom(struct net_device *dev, struct ethtool_eeprom *eeprom, · line 11948

Quoted 5 lines
drivers/net/ethernet/broadcom/tg3.c +5 -0
+		if (need_resched()) {
+			if (signal_pending(current)) {
+				eeprom->len += i;
+				ret = -EINTR;
+				goto eeprom_done;

Why are you incrementing eeprom->len when you break out of the loop due to a signal? You didn't read that extra byte.

eeprom->len is discarded by caller if a failure is returned.
I will resend the patch after incorporating comments and add your Reviewed-by. Thanks.