When the kernel is configured with CONFIG_CPU_IDLE_MULTIPLE_DRIVERS, the cpuidle directory contains a "driver" subdirectory that confuses the current code parsing the C states on ARM platforms, ending up with a C state entry corresponding to the actual driver name instead of a proper C state entry. This patch fixes the code by stopping the parsing if the files that characterise the C states (ie usage) are not found in the respective: /sys/devices/system/cpu/cpuX/cpuidle subdirectory containing C states information. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com&gt; Tested-by: Kevin Hilman <khilman(a)linaro.org&gt; --- Alexandra, Arjan, previous posting here: https://lists.01.org/pipermail/powertop/2014-December/001724.html Please consider pulling this patch.

Thanks, Lorenzo src/cpu/cpu_linux.cpp | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/cpu/cpu_linux.cpp b/src/cpu/cpu_linux.cpp index e1ff165..78fd2d3 100644 --- a/src/cpu/cpu_linux.cpp +++ b/src/cpu/cpu_linux.cpp @@ -83,7 +83,8 @@ void cpu_linux::parse_cstates_start(void) if (file) { file >> usage; file.close(); - } + } else + continue; sprintf(filename + len, "/%s/time", entry->d_name); @@ -172,7 +173,8 @@ void cpu_linux::parse_cstates_end(void) if (file) { file >> usage; file.close(); - } + } else + continue; sprintf(filename + len, "/%s/time", entry->d_name); -- 1.9.1

This patch was added to the current powertop.rc1

AY On 07/07/2015 08:04 AM, Lorenzo Pieralisi wrote: > On Mon, Jun 15, 2015 at 10:57:29AM +0100, Lorenzo Pieralisi wrote: >> When the kernel is configured with CONFIG_CPU_IDLE_MULTIPLE_DRIVERS, >> the cpuidle directory contains a "driver" subdirectory that confuses >> the current code parsing the C states on ARM platforms, ending up >> with a C state entry corresponding to the actual driver name instead >> of a proper C state entry. >> >> This patch fixes the code by stopping the parsing if the files that >> characterise the C states (ie usage) are not found in the respective: >> >> /sys/devices/system/cpu/cpuX/cpuidle >> >> subdirectory containing C states information. >> >> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com&gt; >> Tested-by: Kevin Hilman <khilman(a)linaro.org&gt; >> --- >> Alexandra, Arjan, >> >> previous posting here: >> >> https://lists.01.org/pipermail/powertop/2014-December/001724.html >> >> Please consider pulling this patch. > Gentle ping. > > Thanks, > Lorenzo > >> Thanks, >> Lorenzo >> >> src/cpu/cpu_linux.cpp | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/src/cpu/cpu_linux.cpp b/src/cpu/cpu_linux.cpp >> index e1ff165..78fd2d3 100644 >> --- a/src/cpu/cpu_linux.cpp >> +++ b/src/cpu/cpu_linux.cpp >> @@ -83,7 +83,8 @@ void cpu_linux::parse_cstates_start(void) >> if (file) { >> file >> usage; >> file.close(); >> - } >> + } else >> + continue; >> >> sprintf(filename + len, "/%s/time", entry->d_name); >> >> @@ -172,7 +173,8 @@ void cpu_linux::parse_cstates_end(void) >> if (file) { >> file >> usage; >> file.close(); >> - } >> + } else >> + continue; >> >> sprintf(filename + len, "/%s/time", entry->d_name); >> >> -- >> 1.9.1 >> -- Thank you, <Alexandra>