From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: [PATCH] cpufreq: set value of CPUFREQ_BOOST_FREQ to 0xABABABAB Date: Mon, 24 Mar 2014 12:18:14 +0530 Message-ID: <78187ea173460c871eef31432ec2a80ec657fe30.1395643393.git.viresh.kumar@linaro.org> Return-path: Sender: cpufreq-owner@vger.kernel.org To: rjw@rjwysocki.net Cc: linaro-kernel@lists.linaro.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, srivatsa.bhat@linux.vnet.ibm.com, ego@linux.vnet.ibm.com, svaidy@linux.vnet.ibm.com, l.majewski@samsung.com, Viresh Kumar List-Id: linux-pm@vger.kernel.org Ideally, .driver_data field of struct cpufreq_frequency_table must not be used by core at all. But during a recent change if its value is same as CPUFREQ_BOOST_FREQ macro, then it is treated specially by core. The value of this macro was set to ~2 earlier, i.e. 0xFFFFFFFD. In case some driver is using this field for its own data and sets this field to -3, then with two's complement that value will also become 0xFFFFFFFD. To fix this issue, lets change value of this flag to a very uncommon value which shouldn't be used by any driver unless they want to use BOOST feature. Along with this update comments to make this more clear. Signed-off-by: Viresh Kumar --- Gautham/Vaidy: I hope this fixes the problem we discussed for your patchset. include/linux/cpufreq.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index c48e595..9f25d9d 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -455,12 +455,18 @@ extern struct cpufreq_governor cpufreq_gov_conservative; * FREQUENCY TABLE HELPERS * *********************************************************************/ +/* Special Values of .frequency field */ #define CPUFREQ_ENTRY_INVALID ~0 #define CPUFREQ_TABLE_END ~1 -#define CPUFREQ_BOOST_FREQ ~2 +/* Special Values of .driver_data field */ +#define CPUFREQ_BOOST_FREQ 0xABABABAB struct cpufreq_frequency_table { - unsigned int driver_data; /* driver specific data, not used by core */ + /* + * driver specific data, not used by core unless it is set to + * CPUFREQ_BOOST_FREQ. + */ + unsigned int driver_data; unsigned int frequency; /* kHz - doesn't need to be in ascending * order */ }; -- 1.7.12.rc2.18.g61b472e