therm_adt746x: -3 invalid for parameter limit_adjust

Hi,

after upgrading from 3.11 to 3.12-rc2, the therm_adt746x module could not 
be loaded any more:

  therm_adt746x: `-2' invalid for parameter `limit_adjust'

I've alwasy passed "limit_adjust=-3" (negative 3) to the module via 
modprobe.conf, to lower the max temperature. Up until 3.11, loading the 
module would print:

  adt746x: Lowering max temperatures from 73, 80, 109 to 67, 47, 67

I can load the module without limit_adjust or with positive values, but 
really wanted to lower the temperature, so that the fan would kick in 
earlier. For reference, this is what happens in 3.12-rc2:

 v--- limit_adjust
 |
 0: adt746x: Lowering max temperatures from 73, 80, 109 to 70, 50, 70
 1: adt746x: Lowering max temperatures from 73, 80, 109 to 71, 51, 71
 2: adt746x: Lowering max temperatures from 73, 80, 109 to 72, 52, 72
 3: adt746x: Lowering max temperatures from 73, 80, 109 to 73, 53, 73
 4: adt746x: Lowering max temperatures from 73, 80, 109 to 74, 54, 74
10: adt746x: Lowering max temperatures from 73, 80, 109 to 80, 60, 80

Was passing negative values to therm_adt746x ever supported? 

drivers/macintosh/therm_adt746x.c hasn't been touched in a while, this 
means some other change did it.

Before I attempt a full git bisect, any hints what could have caused this?

Thanks,
Christian.
-- 
BOFH excuse #339:

manager in the cable duct

Hi Christian,

On Thu, 26 Sep 2013 02:16:16 -0700 (PDT), Christian Kujau wrote:

Hi,

after upgrading from 3.11 to 3.12-rc2, the therm_adt746x module could not 
be loaded any more:

  therm_adt746x: `-2' invalid for parameter `limit_adjust'

I've alwasy passed "limit_adjust=-3" (negative 3) to the module via 
modprobe.conf, to lower the max temperature. Up until 3.11, loading the 
module would print:

  adt746x: Lowering max temperatures from 73, 80, 109 to 67, 47, 67

I can load the module without limit_adjust or with positive values, but 
really wanted to lower the temperature, so that the fan would kick in 
earlier. For reference, this is what happens in 3.12-rc2:

 v--- limit_adjust
 |
 0: adt746x: Lowering max temperatures from 73, 80, 109 to 70, 50, 70
 1: adt746x: Lowering max temperatures from 73, 80, 109 to 71, 51, 71
 2: adt746x: Lowering max temperatures from 73, 80, 109 to 72, 52, 72
 3: adt746x: Lowering max temperatures from 73, 80, 109 to 73, 53, 73
 4: adt746x: Lowering max temperatures from 73, 80, 109 to 74, 54, 74
10: adt746x: Lowering max temperatures from 73, 80, 109 to 80, 60, 80

Was passing negative values to therm_adt746x ever supported?

As far as I can see, yes.

drivers/macintosh/therm_adt746x.c hasn't been touched in a while, this 
means some other change did it.

Before I attempt a full git bisect, any hints what could have caused this?

I think it is a bug in:

commit 6072ddc8520b86adfac6939ca32fb6e6c4de017a
Author: Jingoo Han [off-list ref]
Date:   Thu Sep 12 15:14:07 2013 -0700

    kernel: replace strict_strto*() with kstrto*()

The change was a good idea but the code itself is not, it has kstrtoul
in many places where kstrtol should be used. Please try the following
patch, hopefully that should fix your problem:

From: Jean Delvare <redacted>
Subject: kernel/params: Fix handling of signed integer types

Commit 6072ddc8520b86adfac6939ca32fb6e6c4de017a broke the handling
of signed integer types, fix it.

Reported-by: Christian Kujau <redacted>
Signed-off-by: Jean Delvare <redacted>
Cc: Jingoo Han <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
---
 kernel/params.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- linux-3.12-rc2.orig/kernel/params.c	2013-09-24 00:41:09.000000000 +0200
+++ linux-3.12-rc2/kernel/params.c	2013-09-26 11:32:43.434586197 +0200

@@ -254,11 +254,11 @@ int parse_args(const char *doing,
 
 
 STANDARD_PARAM_DEF(byte, unsigned char, "%hhu", unsigned long, kstrtoul);
-STANDARD_PARAM_DEF(short, short, "%hi", long, kstrtoul);
+STANDARD_PARAM_DEF(short, short, "%hi", long, kstrtol);
 STANDARD_PARAM_DEF(ushort, unsigned short, "%hu", unsigned long, kstrtoul);
-STANDARD_PARAM_DEF(int, int, "%i", long, kstrtoul);
+STANDARD_PARAM_DEF(int, int, "%i", long, kstrtol);
 STANDARD_PARAM_DEF(uint, unsigned int, "%u", unsigned long, kstrtoul);
-STANDARD_PARAM_DEF(long, long, "%li", long, kstrtoul);
+STANDARD_PARAM_DEF(long, long, "%li", long, kstrtol);
 STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, kstrtoul);
 
 int param_set_charp(const char *val, const struct kernel_param *kp)

-- 
Jean Delvare

On Thu, 26 Sep 2013 at 11:39, Jean Delvare wrote:

I think it is a bug in:

commit 6072ddc8520b86adfac6939ca32fb6e6c4de017a
Author: Jingoo Han [off-list ref]
Date:   Thu Sep 12 15:14:07 2013 -0700

    kernel: replace strict_strto*() with kstrto*()

The change was a good idea but the code itself is not, it has kstrtoul
in many places where kstrtol should be used. Please try the following
patch, hopefully that should fix your problem:

Bingo, this did it! Applied to 3.12.0-rc2, the limit is now lowered again:

 $ modprobe therm_adt746x limit_adjust=-3
 $ dmesg
 [...]
 adt746x: Lowering max temperatures from 73, 80, 109 to 67, 47, 67

Thanks!

  Tested-by: Christian Kujau [off-list ref]

Christian.

-- 
BOFH excuse #353:

Second-system effect.