diff mbox

[net-next] tg3: Override clock, link aware and link idle mode during NVRAM dump

Message ID 1400864084-27118-1-git-send-email-prashant@broadcom.com
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Prashant Sreedharan May 23, 2014, 4:54 p.m. UTC 
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 <prashant@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
---
 drivers/net/ethernet/broadcom/tg3.c |   44 +++++++++++++++++++++++++++++-----
 1 files changed, 37 insertions(+), 7 deletions(-)

Comments

David Miller May 24, 2014, 4:17 a.m. UTC | #1 
From: Prashant Sreedharan <prashant@broadcom.com>
Date: Fri, 23 May 2014 09:54:44 -0700

> +		if (cpmu_val & (CPMU_CTRL_LINK_AWARE_MODE |
> +				CPMU_CTRL_LINK_IDLE_MODE)) {
> +

Please remove this empty line.

> +			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.

> +		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.
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Prashant Sreedharan May 24, 2014, 8:04 a.m. UTC | #2 
On 5/23/2014 9:17 PM, David Miller wrote:
> From: Prashant Sreedharan <prashant@broadcom.com>
> Date: Fri, 23 May 2014 09:54:44 -0700
>
>> +		if (cpmu_val & (CPMU_CTRL_LINK_AWARE_MODE |
>> +				CPMU_CTRL_LINK_IDLE_MODE)) {
>> +
>
> Please remove this empty line.
Ok
>
>> +			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.
>
Will fix indentation.
>> +		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.
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diff mbox

Patch

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index ccd9015..c59e938 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -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)