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From: Yi Yang <yi.y.yang@intel.com>
To: linux-acpi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, lenb@kernel.org,
	acpi-bugzilla@lists.sourceforge.net
Subject: [PATCH] ACPI: fix processor throttling set error
Date: Mon, 07 Jan 2008 14:56:01 +0800	[thread overview]
Message-ID: <1199688961.3551.19.camel@yangyi-dev.bj.intel.com> (raw)
In-Reply-To: <1199434602.19185.1.camel@yangyi-dev.bj.intel.com>

Subject: ACPI: fix processor throttling set error
From: Yi Yang <yi.y.yang@intel.com>

When echo some invalid values to /proc/acpi/processor/*/throttling,
there isn't any error info returned, on the contray, it sets
throttling value to some T* successfully, obviously, this is incorrect,
a correct way should be to let it fail and return error info.

This patch fixed the aforementioned issue, it also enables
/proc/acpi/processor/*/throttling to accept such values as 't0' and 'T0',
it also strictly limits /proc/acpi/processor/*/throttling only to accept
 "*", "t*" and "T*", "*" is the throttling state value the processor can
support, current, it is 0 - 7.

Before applying this patch, the test result is below:

[root@localhost acpi]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T1
state available: T0 to T7
states:
    T0:                  100%
   *T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost acpi]# echo "1xxxxxx" > /proc/acpi/processor/CPU0/throttling
[root@localhost acpi]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T1
state available: T0 to T7
states:
    T0:                  100%
   *T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost acpi]# echo "0" > /proc/acpi/processor/CPU0/throttling
[root@localhost acpi]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
state available: T0 to T7
states:
   *T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost acpi]# cd /
[root@localhost /]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
state available: T0 to T7
states:
   *T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost /]# echo "T0" > /proc/acpi/processor/CPU0/throttling
[root@localhost /]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
state available: T0 to T7
states:
   *T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost /]# echo "T7" > /proc/acpi/processor/CPU0/throttling
[root@localhost /]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
state available: T0 to T7
states:
   *T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost /]# echo "T100" > /proc/acpi/processor/CPU0/throttling
[root@localhost /]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
state available: T0 to T7
states:
   *T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost /]# echo "xxx" > /proc/acpi/processor/CPU0/throttling
[root@localhost /]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
state available: T0 to T7
states:
   *T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost /]# echo "2xxxx" > /proc/acpi/processor/CPU0/throttling
[root@localhost /]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T2
state available: T0 to T7
states:
    T0:                  100%
    T1:                  87%
   *T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost /]# echo "" > /proc/acpi/processor/CPU0/throttling
[root@localhost /]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
state available: T0 to T7
states:
   *T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost /]# echo "7777" > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost /]# echo "7xxx" > /proc/acpi/processor/CPU0/throttling
[root@localhost /]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T7
state available: T0 to T7
states:
    T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
   *T7:                  12%
[root@localhost /]#


After applying this patch, the test result is below:

[root@localhost linux-2.6.24-rc6]# echo > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo "" > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo "0" > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# echo "t0" > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# echo "T0" > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T0
state available: T0 to T7
states:
   *T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
    T7:                  12%
[root@localhost linux-2.6.24-rc6]# echo "T7" > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T7
state available: T0 to T7
states:
    T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
   *T7:                  12%
[root@localhost linux-2.6.24-rc6]# echo "T8" > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# vi drivers/acpi/processor_throttling.c
[root@localhost linux-2.6.24-rc6]# echo "T8" > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo "t7" > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# echo "t70" > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo "70" > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo "7000" > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo "70" > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo "xxx" > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo -n > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# echo -n "" > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# echo $?
0
[root@localhost linux-2.6.24-rc6]# echo -n "" > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T7
state available: T0 to T7
states:
    T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
   *T7:                  12%
[root@localhost linux-2.6.24-rc6]# echo -n "" > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# cat /proc/acpi/processor/CPU0/throttling
state count:             8
active state:            T7
state available: T0 to T7
states:
    T0:                  100%
    T1:                  87%
    T2:                  75%
    T3:                  62%
    T4:                  50%
    T5:                  37%
    T6:                  25%
   *T7:                  12%
[root@localhost linux-2.6.24-rc6]# echo t0 > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# echo T0 > /proc/acpi/processor/CPU0/throttling
[root@localhost linux-2.6.24-rc6]# echo Tt0 > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]# echo T > /proc/acpi/processor/CPU0/throttling
-bash: echo: write error: Invalid argument
[root@localhost linux-2.6.24-rc6]#

Signed-off-by: Yi Yang <yi.y.yang@intel.com>
---
 processor_throttling.c |   24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index 6742d7b..10035a6 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -898,7 +898,10 @@ static ssize_t acpi_processor_write_throttling(struct file *file,
 	int result = 0;
 	struct seq_file *m = file->private_data;
 	struct acpi_processor *pr = m->private;
-	char state_string[12] = { '\0' };
+	char state_string[5] = "";
+	char *charp = NULL;
+	size_t state_val = 0;
+	char tmpbuf[5] = "";
 
 	if (!pr || (count > sizeof(state_string) - 1))
 		return -EINVAL;
@@ -907,10 +910,23 @@ static ssize_t acpi_processor_write_throttling(struct file *file,
 		return -EFAULT;
 
 	state_string[count] = '\0';
+	if ((count > 0) && (state_string[count-1] == '\n'))
+		state_string[count-1] = '\0';
 
-	result = acpi_processor_set_throttling(pr,
-					       simple_strtoul(state_string,
-							      NULL, 0));
+	charp = state_string;
+	if ((state_string[0] == 't') || (state_string[0] == 'T'))
+		charp++;
+
+	state_val = simple_strtoul(charp, NULL, 0);
+	if (state_val >= pr->throttling.state_count)
+		return -EINVAL;
+
+	snprintf(tmpbuf, 5, "%d", state_val);
+
+	if (strcmp(tmpbuf, charp) != 0)
+		return -EINVAL;
+
+	result = acpi_processor_set_throttling(pr, state_val);
 	if (result)
 		return result;
 



  reply	other threads:[~2008-01-07  7:45 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-27  6:47 [PATCH linux-acpi] Fix /proc/acpi/alarm " Yi Yang
2007-12-27  8:41 ` [PATCH linux-acpi] Remove superfluous code and correct counting error in function acpi_system_write_alarm Yi Yang
2007-12-29  8:22   ` [PATCH linux-acpi] Correct wakeup set error and append a new column PCI ID Yi Yang
2008-01-01 23:20     ` Pavel Machek
2008-01-02  2:03       ` Yi Yang
2008-01-02 16:09         ` Pavel Machek
2008-01-03  2:02           ` Yi Yang
2008-01-03  2:11           ` Yi Yang
2008-01-04  8:16     ` [PATCH linux-acpi] fix acpi fan state set error Yi Yang
2008-01-07  6:56       ` Yi Yang [this message]
2008-01-08  3:21         ` [PATCH] ACPI: fix processor limit " Yi Yang
2008-01-24  0:45           ` [PATCH] ACPI: create proc entry 'power' only if C2 or C3 is supported Yi Yang
2008-01-24 14:43             ` Mark Lord
2008-01-09 22:21         ` [PATCH] ACPI: Add sysfs interface for acpi device wakeup Yi Yang
2008-01-10  7:43           ` Maxim Levitsky
2008-01-09 23:59             ` Yi Yang
2008-01-10 10:30               ` Matthew Garrett
2008-01-13 18:16               ` Pavel Machek
2008-01-11  8:16             ` Zhang Rui
2008-01-10 23:55               ` Yi Yang
2008-03-19 13:06                 ` Thomas Renninger
2008-03-19 14:37                   ` Yi Yang
2008-03-20  4:32                     ` Zhao Yakui
2008-03-19 18:52                   ` David Brownell
2008-03-20  5:12                     ` Zhao Yakui
2008-03-20  6:12                       ` David Brownell

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