powerpc: Fix Book-E watchdog timer interval setting

This patch fixes the setting of the Book-E watchdog timer interval setup
on initialization and by ioctl().

Tested on PPC440EPx sequoia evaluation board.

Signed-off-by: Matthias Fuchs <redacted>
---
 drivers/watchdog/booke_wdt.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/drivers/watchdog/booke_wdt.c b/drivers/watchdog/booke_wdt.c
index 7708244..9db5478 100644
--- a/drivers/watchdog/booke_wdt.c
+++ b/drivers/watchdog/booke_wdt.c

@@ -42,8 +42,10 @@ u32 booke_wdt_period = WDT_PERIOD_DEFAULT;
 
 #ifdef	CONFIG_FSL_BOOKE
 #define WDTP(x)		((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15))
+#define WDTP_MASK	(WDTP(63))
 #else
 #define WDTP(x)		(TCR_WP(x))
+#define WDTP_MASK	(TCR_WP_MASK)
 #endif
 
 static DEFINE_SPINLOCK(booke_wdt_lock);

@@ -65,6 +67,7 @@ static void __booke_wdt_enable(void *data)
 	/* clear status before enabling watchdog */
 	__booke_wdt_ping(NULL);
 	val = mfspr(SPRN_TCR);
+	val &= ~WDTP_MASK;
 	val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period));
 
 	mtspr(SPRN_TCR, val);

@@ -106,7 +109,8 @@ static int booke_wdt_ioctl(struct inode *inode, struct file *file,
 	case WDIOC_SETTIMEOUT:
 		if (get_user(booke_wdt_period, p))
 			return -EFAULT;
-		mtspr(SPRN_TCR, (mfspr(SPRN_TCR)&~WDTP(0))|WDTP(booke_wdt_period));
+		tmp = mfspr(SPRN_TCR) & ~WDTP_MASK;
+		mtspr(SPRN_TCR, tmp | WDTP(booke_wdt_period));
 		return 0;
 	case WDIOC_GETTIMEOUT:
 		return put_user(booke_wdt_period, p);

-- 
1.5.3

On Aug 7, 2008, at 7:48 AM, Matthias Fuchs wrote:

This patch fixes the setting of the Book-E watchdog timer interval setup
on initialization and by ioctl().

Tested on PPC440EPx sequoia evaluation board.

Signed-off-by: Matthias Fuchs <redacted>
---
drivers/watchdog/booke_wdt.c |    6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)

can you be more explicit about what the bug was.

- k

Sure,

the former line:

 mtspr(SPRN_TCR, (mfspr(SPRN_TCR)&~WDTP(0))|WDTP(booke_wdt_period));

tries to mask the wdt interval period bits by and'ing with ~WDTP(0) which
is 0xffffffff. So no bits are cleared and or'ing a new value does not change anything.
The default interval is '3' which is the maximum, so any attempt to set a new
interval keeps the former '3'.

The patch correctly masks the period bits in SPRN_TCR before writing the new value.

That's all.

Matthias

On Thursday 07 August 2008 15:19, Kumar Gala wrote:

On Aug 7, 2008, at 7:48 AM, Matthias Fuchs wrote:

quoted

This patch fixes the setting of the Book-E watchdog timer interval  
setup
on initialization and by ioctl().

Tested on PPC440EPx sequoia evaluation board.

Signed-off-by: Matthias Fuchs <redacted>
---
drivers/watchdog/booke_wdt.c |    6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)

can you be more explicit about what the bug was.

- k

Hi Kumar,

should I resend this my patch? Is there chance to get it applied.
It really fixes a bug!

Matthias

On Thursday 07 August 2008 15:19:10 Kumar Gala wrote:

On Aug 7, 2008, at 7:48 AM, Matthias Fuchs wrote:

quoted

This patch fixes the setting of the Book-E watchdog timer interval
setup
on initialization and by ioctl().

Tested on PPC440EPx sequoia evaluation board.

Signed-off-by: Matthias Fuchs <redacted>
---
drivers/watchdog/booke_wdt.c |    6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)

can you be more explicit about what the bug was.

- k
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev

Please repost and I'll look at it again.. I'm trying to be more diligent about patchworks.ozlabs.org and tracking things there.

- k

On Sep 19, 2008, at 4:28 PM, Matthias Fuchs wrote:

Hi Kumar,

should I resend this my patch? Is there chance to get it applied.
It really fixes a bug!

Matthias

On Thursday 07 August 2008 15:19:10 Kumar Gala wrote:

quoted

On Aug 7, 2008, at 7:48 AM, Matthias Fuchs wrote:

quoted

This patch fixes the setting of the Book-E watchdog timer interval
setup
on initialization and by ioctl().

Tested on PPC440EPx sequoia evaluation board.

Signed-off-by: Matthias Fuchs <redacted>
---
drivers/watchdog/booke_wdt.c |    6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)

can you be more explicit about what the bug was.

- k
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev

This patch fixes the setting of the Book-E watchdog timer interval setup
on initialization and by ioctl().

On initialization the period bits have to be masked before setting
a new period.

In WDIOC_SETTIMEOUT ioctl we have to use the currect mask.

Signed-off-by: Matthias Fuchs <redacted>
---
 drivers/watchdog/booke_wdt.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/watchdog/booke_wdt.c b/drivers/watchdog/booke_wdt.c
index c3b78a7..41ba9b8 100644
--- a/drivers/watchdog/booke_wdt.c
+++ b/drivers/watchdog/booke_wdt.c

@@ -42,8 +42,10 @@ u32 booke_wdt_period = WDT_PERIOD_DEFAULT;
 
 #ifdef	CONFIG_FSL_BOOKE
 #define WDTP(x)		((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15))
+#define WDTP_MASK	(WDTP(63))
 #else
 #define WDTP(x)		(TCR_WP(x))
+#define WDTP_MASK	(TCR_WP_MASK)
 #endif
 
 static DEFINE_SPINLOCK(booke_wdt_lock);

@@ -65,6 +67,7 @@ static void __booke_wdt_enable(void *data)
 	/* clear status before enabling watchdog */
 	__booke_wdt_ping(NULL);
 	val = mfspr(SPRN_TCR);
+	val &= ~WDTP_MASK;
 	val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period));
 
 	mtspr(SPRN_TCR, val);

@@ -114,7 +117,7 @@ static long booke_wdt_ioctl(struct file *file,
 	case WDIOC_SETTIMEOUT:
 		if (get_user(booke_wdt_period, p))
 			return -EFAULT;
-		mtspr(SPRN_TCR, (mfspr(SPRN_TCR) & ~WDTP(0)) |
+		mtspr(SPRN_TCR, (mfspr(SPRN_TCR) & ~WDTP_MASK) |
 						WDTP(booke_wdt_period));
 		return 0;
 	case WDIOC_GETTIMEOUT:

-- 
1.5.3

On Tue, Sep 23, 2008 at 10:04 AM, Matthias Fuchs
[off-list ref] wrote:

WDTP(63) is "((((63-63)&0x3)<<30)|(((63-63)&0x3c)<<15))", which is
equal to 0.  Shouldn't WDTP_MASK be equal to "(3 << 30) | (15 << 15)"?

-- 
Timur Tabi
Linux kernel developer at Freescale

Timur,

I missed you posting. But you are right. My patch is ok for 4xx CPUs and touching 
the CONFIG_FSL_BOOKE path was not my intention.

So for CONFIG_FSL_BOOKE WDTP_MASK should be WDTP(0). There is still a slightly difference
between WDTP(0)="(3 << 30) | (0x3c << 15)" and "(3 << 30) | (15 << 15)". 
Can you check that please and I will resend my patch.

Thanks for pointing that out.

Matthias

On Tuesday 23 September 2008 18:31, Timur Tabi wrote:

On Tue, Sep 23, 2008 at 10:04 AM, Matthias Fuchs
[off-list ref] wrote:

quoted

 #ifdef CONFIG_FSL_BOOKE
 #define WDTP(x)                ((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15))
+#define WDTP_MASK      (WDTP(63))

WDTP(63) is "((((63-63)&0x3)<<30)|(((63-63)&0x3c)<<15))", which is
equal to 0.  Shouldn't WDTP_MASK be equal to "(3 << 30) | (15 << 15)"?

Matthias Fuchs wrote:

Timur,

I missed you posting. But you are right. My patch is ok for 4xx CPUs and touching 
the CONFIG_FSL_BOOKE path was not my intention.

So for CONFIG_FSL_BOOKE WDTP_MASK should be WDTP(0). There is still a slightly difference
between WDTP(0)="(3 << 30) | (0x3c << 15)" and "(3 << 30) | (15 << 15)". 
Can you check that please and I will resend my patch.

Yes, I think WDTP(0) is correct for Book E.

-- 
Timur Tabi
Linux kernel developer at Freescale