From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Brandewie Subject: Re: [PATCH V4 1/2] cpufreq: Mark x86 drivers with CPUFREQ_SKIP_INITIAL_FREQ_CHECK flag Date: Mon, 02 Dec 2013 07:23:01 -0800 Message-ID: <529CA5D5.9010008@gmail.com> References: <0875dc1b263f39081232c560fc72c15cd42dfc6f.1385734305.git.viresh.kumar@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <0875dc1b263f39081232c560fc72c15cd42dfc6f.1385734305.git.viresh.kumar@linaro.org> Sender: cpufreq-owner@vger.kernel.org To: Viresh Kumar , rjw@rjwysocki.net Cc: linaro-kernel@lists.linaro.org, patches@linaro.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, nm@ti.com, ceh@ti.com List-Id: linux-pm@vger.kernel.org Sorry for late response to these threads. Holiday weekend in the US. On 11/29/2013 06:14 AM, Viresh Kumar wrote: > On some systems we can't really say what frequency we're running at the moment > and so for these we shouldn't check if we are running at a frequency present in > frequency table. For now mark all x86 drivers with this flag: > CPUFREQ_SKIP_INITIAL_FREQ_CHECK. > > This patch also defines this macro. It will be used in cpufreq.c in the next > patch. > > Signed-off-by: Viresh Kumar > --- > V3->V4: > - Reversed the order of patches > - Moved definition of CPUFREQ_SKIP_INITIAL_FREQ_CHECK to patch 1/2 instead of > 2/2. > > drivers/cpufreq/acpi-cpufreq.c | 1 + > drivers/cpufreq/cpufreq-nforce2.c | 1 + > drivers/cpufreq/e_powersaver.c | 1 + > drivers/cpufreq/elanfreq.c | 1 + > drivers/cpufreq/gx-suspmod.c | 1 + > drivers/cpufreq/ia64-acpi-cpufreq.c | 1 + > drivers/cpufreq/intel_pstate.c | 2 +- NAK for intel_pstate. The code that will use this flag also uses has_target() which is false for intel_pstate. I think the logic for this patch is inverted. Why are we adding a flag to drivers where the bug cannot exist? I would be happier if the flag was CPUFREQ_NEED_INITIAL_FREQ_WORKAROUND to mark the platforms where the bug may exist let those platforms cary the flag for the next 10+ years. I still believe that this bug should be dealt with in platform specific code since this is working around a bootloader bug. Are there platforms in the wild that even need this code or is this to support early platform bringup? > drivers/cpufreq/longhaul.c | 1 + > drivers/cpufreq/longrun.c | 2 +- > drivers/cpufreq/p4-clockmod.c | 1 + > drivers/cpufreq/pcc-cpufreq.c | 2 +- > drivers/cpufreq/powernow-k6.c | 1 + > drivers/cpufreq/powernow-k7.c | 1 + > drivers/cpufreq/powernow-k8.c | 3 ++- > drivers/cpufreq/sc520_freq.c | 1 + > drivers/cpufreq/speedstep-centrino.c | 1 + > drivers/cpufreq/speedstep-ich.c | 1 + > drivers/cpufreq/speedstep-smi.c | 1 + > include/linux/cpufreq.h | 9 +++++++++ > 19 files changed, 28 insertions(+), 4 deletions(-) > > diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c > index caf41eb..b8e4f79 100644 > --- a/drivers/cpufreq/acpi-cpufreq.c > +++ b/drivers/cpufreq/acpi-cpufreq.c > @@ -903,6 +903,7 @@ static struct freq_attr *acpi_cpufreq_attr[] = { > }; > > static struct cpufreq_driver acpi_cpufreq_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = acpi_cpufreq_target, > .bios_limit = acpi_processor_get_bios_limit, > diff --git a/drivers/cpufreq/cpufreq-nforce2.c b/drivers/cpufreq/cpufreq-nforce2.c > index a05b876..b3222f6 100644 > --- a/drivers/cpufreq/cpufreq-nforce2.c > +++ b/drivers/cpufreq/cpufreq-nforce2.c > @@ -370,6 +370,7 @@ static int nforce2_cpu_exit(struct cpufreq_policy *policy) > } > > static struct cpufreq_driver nforce2_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .name = "nforce2", > .verify = nforce2_verify, > .target = nforce2_target, > diff --git a/drivers/cpufreq/e_powersaver.c b/drivers/cpufreq/e_powersaver.c > index 9012b8b..0826bda 100644 > --- a/drivers/cpufreq/e_powersaver.c > +++ b/drivers/cpufreq/e_powersaver.c > @@ -389,6 +389,7 @@ static int eps_cpu_exit(struct cpufreq_policy *policy) > } > > static struct cpufreq_driver eps_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = eps_target, > .init = eps_cpu_init, > diff --git a/drivers/cpufreq/elanfreq.c b/drivers/cpufreq/elanfreq.c > index de08acf..426d14d 100644 > --- a/drivers/cpufreq/elanfreq.c > +++ b/drivers/cpufreq/elanfreq.c > @@ -194,6 +194,7 @@ __setup("elanfreq=", elanfreq_setup); > > > static struct cpufreq_driver elanfreq_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .get = elanfreq_get_cpu_frequency, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = elanfreq_target, > diff --git a/drivers/cpufreq/gx-suspmod.c b/drivers/cpufreq/gx-suspmod.c > index d83e826..7bfad48 100644 > --- a/drivers/cpufreq/gx-suspmod.c > +++ b/drivers/cpufreq/gx-suspmod.c > @@ -438,6 +438,7 @@ static int cpufreq_gx_cpu_init(struct cpufreq_policy *policy) > * MediaGX/Geode GX initialize cpufreq driver > */ > static struct cpufreq_driver gx_suspmod_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .get = gx_get_cpuspeed, > .verify = cpufreq_gx_verify, > .target = cpufreq_gx_target, > diff --git a/drivers/cpufreq/ia64-acpi-cpufreq.c b/drivers/cpufreq/ia64-acpi-cpufreq.c > index 53c6ac6..907bf9a 100644 > --- a/drivers/cpufreq/ia64-acpi-cpufreq.c > +++ b/drivers/cpufreq/ia64-acpi-cpufreq.c > @@ -344,6 +344,7 @@ acpi_cpufreq_cpu_exit ( > > > static struct cpufreq_driver acpi_cpufreq_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = acpi_cpufreq_target, > .get = acpi_cpufreq_get, > diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c > index 5f1cbae..6c8f5d3 100644 > --- a/drivers/cpufreq/intel_pstate.c > +++ b/drivers/cpufreq/intel_pstate.c > @@ -725,7 +725,7 @@ static int intel_pstate_cpu_init(struct cpufreq_policy *policy) > } > > static struct cpufreq_driver intel_pstate_driver = { > - .flags = CPUFREQ_CONST_LOOPS, > + .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = intel_pstate_verify_policy, > .setpolicy = intel_pstate_set_policy, > .get = intel_pstate_get, > diff --git a/drivers/cpufreq/longhaul.c b/drivers/cpufreq/longhaul.c > index 45bafdd..16c0a37 100644 > --- a/drivers/cpufreq/longhaul.c > +++ b/drivers/cpufreq/longhaul.c > @@ -909,6 +909,7 @@ static int longhaul_cpu_init(struct cpufreq_policy *policy) > } > > static struct cpufreq_driver longhaul_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = longhaul_target, > .get = longhaul_get, > diff --git a/drivers/cpufreq/longrun.c b/drivers/cpufreq/longrun.c > index 074971b..b67d341 100644 > --- a/drivers/cpufreq/longrun.c > +++ b/drivers/cpufreq/longrun.c > @@ -278,7 +278,7 @@ static int longrun_cpu_init(struct cpufreq_policy *policy) > > > static struct cpufreq_driver longrun_driver = { > - .flags = CPUFREQ_CONST_LOOPS, > + .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = longrun_verify_policy, > .setpolicy = longrun_set_policy, > .get = longrun_get, > diff --git a/drivers/cpufreq/p4-clockmod.c b/drivers/cpufreq/p4-clockmod.c > index 3d1cba9..92b7e2b 100644 > --- a/drivers/cpufreq/p4-clockmod.c > +++ b/drivers/cpufreq/p4-clockmod.c > @@ -234,6 +234,7 @@ static unsigned int cpufreq_p4_get(unsigned int cpu) > } > > static struct cpufreq_driver p4clockmod_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = cpufreq_p4_target, > .init = cpufreq_p4_cpu_init, > diff --git a/drivers/cpufreq/pcc-cpufreq.c b/drivers/cpufreq/pcc-cpufreq.c > index e2b4f40..eafe4ca 100644 > --- a/drivers/cpufreq/pcc-cpufreq.c > +++ b/drivers/cpufreq/pcc-cpufreq.c > @@ -571,7 +571,7 @@ static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy) > } > > static struct cpufreq_driver pcc_cpufreq_driver = { > - .flags = CPUFREQ_CONST_LOOPS, > + .flags = CPUFREQ_CONST_LOOPS | CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .get = pcc_get_freq, > .verify = pcc_cpufreq_verify, > .target = pcc_cpufreq_target, > diff --git a/drivers/cpufreq/powernow-k6.c b/drivers/cpufreq/powernow-k6.c > index 643e795..fe60021 100644 > --- a/drivers/cpufreq/powernow-k6.c > +++ b/drivers/cpufreq/powernow-k6.c > @@ -150,6 +150,7 @@ static unsigned int powernow_k6_get(unsigned int cpu) > } > > static struct cpufreq_driver powernow_k6_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = powernow_k6_target, > .init = powernow_k6_cpu_init, > diff --git a/drivers/cpufreq/powernow-k7.c b/drivers/cpufreq/powernow-k7.c > index 946708a..4e67abc 100644 > --- a/drivers/cpufreq/powernow-k7.c > +++ b/drivers/cpufreq/powernow-k7.c > @@ -679,6 +679,7 @@ static int powernow_cpu_exit(struct cpufreq_policy *policy) > } > > static struct cpufreq_driver powernow_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = powernow_target, > .get = powernow_get, > diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c > index 0023c7d..ffe89ba 100644 > --- a/drivers/cpufreq/powernow-k8.c > +++ b/drivers/cpufreq/powernow-k8.c > @@ -1204,7 +1204,8 @@ out: > } > > static struct cpufreq_driver cpufreq_amd64_driver = { > - .flags = CPUFREQ_ASYNC_NOTIFICATION, > + .flags = CPUFREQ_ASYNC_NOTIFICATION | > + CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = powernowk8_target, > .bios_limit = acpi_processor_get_bios_limit, > diff --git a/drivers/cpufreq/sc520_freq.c b/drivers/cpufreq/sc520_freq.c > index 6adb354..d6a1cf6 100644 > --- a/drivers/cpufreq/sc520_freq.c > +++ b/drivers/cpufreq/sc520_freq.c > @@ -89,6 +89,7 @@ static int sc520_freq_cpu_init(struct cpufreq_policy *policy) > > > static struct cpufreq_driver sc520_freq_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .get = sc520_freq_get_cpu_frequency, > .verify = cpufreq_generic_frequency_table_verify, > .target_index = sc520_freq_target, > diff --git a/drivers/cpufreq/speedstep-centrino.c b/drivers/cpufreq/speedstep-centrino.c > index 4e1daca..887fd43 100644 > --- a/drivers/cpufreq/speedstep-centrino.c > +++ b/drivers/cpufreq/speedstep-centrino.c > @@ -505,6 +505,7 @@ out: > } > > static struct cpufreq_driver centrino_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .name = "centrino", /* should be speedstep-centrino, > but there's a 16 char limit */ > .init = centrino_cpu_init, > diff --git a/drivers/cpufreq/speedstep-ich.c b/drivers/cpufreq/speedstep-ich.c > index 7639b2b..67596e7 100644 > --- a/drivers/cpufreq/speedstep-ich.c > +++ b/drivers/cpufreq/speedstep-ich.c > @@ -307,6 +307,7 @@ static int speedstep_cpu_init(struct cpufreq_policy *policy) > > > static struct cpufreq_driver speedstep_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .name = "speedstep-ich", > .verify = cpufreq_generic_frequency_table_verify, > .target_index = speedstep_target, > diff --git a/drivers/cpufreq/speedstep-smi.c b/drivers/cpufreq/speedstep-smi.c > index 0f5326d..4f23289 100644 > --- a/drivers/cpufreq/speedstep-smi.c > +++ b/drivers/cpufreq/speedstep-smi.c > @@ -308,6 +308,7 @@ static int speedstep_resume(struct cpufreq_policy *policy) > } > > static struct cpufreq_driver speedstep_driver = { > + .flags = CPUFREQ_SKIP_INITIAL_FREQ_CHECK, > .name = "speedstep-smi", > .verify = cpufreq_generic_frequency_table_verify, > .target_index = speedstep_target, > diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h > index ee5fe9d..13b8802 100644 > --- a/include/linux/cpufreq.h > +++ b/include/linux/cpufreq.h > @@ -252,6 +252,15 @@ struct cpufreq_driver { > */ > #define CPUFREQ_ASYNC_NOTIFICATION (1 << 4) > > +/* > + * Set by drivers which don't want cpufreq core to check if CPU is running at a > + * frequency present in freq-table exposed by the driver. For other drivers if > + * CPU is found running at an out of table freq, we will try to set it to a freq > + * from the table. And if that fails, we will stop further boot process by > + * issuing a BUG_ON(). > + */ > +#define CPUFREQ_SKIP_INITIAL_FREQ_CHECK (1 << 5) > + > int cpufreq_register_driver(struct cpufreq_driver *driver_data); > int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); > >