ACPI: fix processor throttling set error
http://bugzilla.kernel.org/show_bug.cgi?id=9704
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>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commit