| Message ID | 20200303170948.1.I108734f38ade020c3e5da825839dca11d2a2ff87@changeid (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
| Series | [v3] intel_idle: Add Comet Lake support | expand |
On Tue, Mar 3, 2020 at 10:10 AM Harry Pan <harry.pan@intel.com> wrote: > > Add a general C-state table in order to support Comet Lake. > > Signed-off-by: Harry Pan <harry.pan@intel.com> > > --- > > drivers/idle/intel_idle.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c > index d55606608ac8..05bce595fafe 100644 > --- a/drivers/idle/intel_idle.c > +++ b/drivers/idle/intel_idle.c > @@ -1067,6 +1067,11 @@ static const struct idle_cpu idle_cpu_dnv = { > .use_acpi = true, > }; > > +static const struct idle_cpu idle_cpu_cml = { > + .state_table = skl_cstates, > + .disable_promotion_to_c1e = true, .use_acpi = true, missing? Otherwise you can just use idle_cpu_skl as is, can't you? > +}; > + > static const struct x86_cpu_id intel_idle_ids[] __initconst = { > INTEL_CPU_FAM6(NEHALEM_EP, idle_cpu_nhx), > INTEL_CPU_FAM6(NEHALEM, idle_cpu_nehalem), > @@ -1105,6 +1110,8 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = { > INTEL_CPU_FAM6(ATOM_GOLDMONT_PLUS, idle_cpu_bxt), > INTEL_CPU_FAM6(ATOM_GOLDMONT_D, idle_cpu_dnv), > INTEL_CPU_FAM6(ATOM_TREMONT_D, idle_cpu_dnv), > + INTEL_CPU_FAM6(COMETLAKE_L, idle_cpu_cml), > + INTEL_CPU_FAM6(COMETLAKE, idle_cpu_cml), > {} > }; > > -- > 2.24.1 >
Hi Rafael, Yes, I skipped it considering to align CML-U V0 and A0 stepping w/ the same table; I sent v4 for your review. In the other hand, I am proposing using _CST as long term plan in CrOS dev teams. Sincerely, Harry > On Mar 4, 2020, at 17:53, Rafael J. Wysocki <rafael@kernel.org> wrote: > > On Tue, Mar 3, 2020 at 10:10 AM Harry Pan <harry.pan@intel.com> wrote: >> >> Add a general C-state table in order to support Comet Lake. >> >> Signed-off-by: Harry Pan <harry.pan@intel.com> >> >> --- >> >> drivers/idle/intel_idle.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c >> index d55606608ac8..05bce595fafe 100644 >> --- a/drivers/idle/intel_idle.c >> +++ b/drivers/idle/intel_idle.c >> @@ -1067,6 +1067,11 @@ static const struct idle_cpu idle_cpu_dnv = { >> .use_acpi = true, >> }; >> >> +static const struct idle_cpu idle_cpu_cml = { >> + .state_table = skl_cstates, >> + .disable_promotion_to_c1e = true, > > .use_acpi = true, > > missing? Otherwise you can just use idle_cpu_skl as is, can't you? > >> +}; >> + >> static const struct x86_cpu_id intel_idle_ids[] __initconst = { >> INTEL_CPU_FAM6(NEHALEM_EP, idle_cpu_nhx), >> INTEL_CPU_FAM6(NEHALEM, idle_cpu_nehalem), >> @@ -1105,6 +1110,8 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = { >> INTEL_CPU_FAM6(ATOM_GOLDMONT_PLUS, idle_cpu_bxt), >> INTEL_CPU_FAM6(ATOM_GOLDMONT_D, idle_cpu_dnv), >> INTEL_CPU_FAM6(ATOM_TREMONT_D, idle_cpu_dnv), >> + INTEL_CPU_FAM6(COMETLAKE_L, idle_cpu_cml), >> + INTEL_CPU_FAM6(COMETLAKE, idle_cpu_cml), >> {} >> }; >> >> -- >> 2.24.1 >>
On Wed, Mar 4, 2020 at 12:57 PM Pan, Harry <harry.pan@intel.com> wrote: > > Hi Rafael, > > Yes, I skipped it considering to align CML-U V0 and A0 stepping w/ the same table; I sent v4 for your review. Skipping that flag is risky, because it may cause some C-states to be enabled on systems where they have not been validated (e.g. systems shipping with other OSes which only use _CST C-states). There were problems related to that in the past which is one of the reasons for adding _CST support to intel_idle. use_acpi should be set for all new platforms going forward as a rule. > In the other hand, I am proposing using _CST as long term plan in CrOS dev teams. That I obviously agree with. :-) > > On Mar 4, 2020, at 17:53, Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > On Tue, Mar 3, 2020 at 10:10 AM Harry Pan <harry.pan@intel.com> wrote: > >> > >> Add a general C-state table in order to support Comet Lake. > >> > >> Signed-off-by: Harry Pan <harry.pan@intel.com> > >> > >> --- > >> > >> drivers/idle/intel_idle.c | 7 +++++++ > >> 1 file changed, 7 insertions(+) > >> > >> diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c > >> index d55606608ac8..05bce595fafe 100644 > >> --- a/drivers/idle/intel_idle.c > >> +++ b/drivers/idle/intel_idle.c > >> @@ -1067,6 +1067,11 @@ static const struct idle_cpu idle_cpu_dnv = { > >> .use_acpi = true, > >> }; > >> > >> +static const struct idle_cpu idle_cpu_cml = { > >> + .state_table = skl_cstates, > >> + .disable_promotion_to_c1e = true, > > > > .use_acpi = true, > > > > missing? Otherwise you can just use idle_cpu_skl as is, can't you? > > > >> +}; > >> + > >> static const struct x86_cpu_id intel_idle_ids[] __initconst = { > >> INTEL_CPU_FAM6(NEHALEM_EP, idle_cpu_nhx), > >> INTEL_CPU_FAM6(NEHALEM, idle_cpu_nehalem), > >> @@ -1105,6 +1110,8 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = { > >> INTEL_CPU_FAM6(ATOM_GOLDMONT_PLUS, idle_cpu_bxt), > >> INTEL_CPU_FAM6(ATOM_GOLDMONT_D, idle_cpu_dnv), > >> INTEL_CPU_FAM6(ATOM_TREMONT_D, idle_cpu_dnv), > >> + INTEL_CPU_FAM6(COMETLAKE_L, idle_cpu_cml), > >> + INTEL_CPU_FAM6(COMETLAKE, idle_cpu_cml), > >> {} > >> }; > >> > >> -- > >> 2.24.1 > >>
Hi Rafael, Thanks for the comments. I have some questions, I am wondering if you can share upstream thought w.r.t the future development of intel_idle. - It looks to me since v5.6 intel_idle will prefer _CST of ACPI rather than the general table embedded in this driver. - Any pros and cons of using the tables of _CST in firmware and embedded one in the kernel? - Can the table in _CST archive more optimal idle states management? If there is already any reference, documents I missed, kindly enlighten me then I would like to read it first before refining the questions. Thanks and take care, Harry
On Mon, Mar 9, 2020 at 10:07 AM Pan, Harry <harry.pan@intel.com> wrote: > > Hi Rafael, > > Thanks for the comments. > I have some questions, I am wondering if you can share upstream thought w.r.t the future development of intel_idle. > > - It looks to me since v5.6 intel_idle will prefer _CST of ACPI rather than the general table embedded in this driver. Not exactly. The rules are as follows: * If there is a built-in table for the given processor in the driver, it will be used, but the C-states that are not exposed in _CST will be disabled by default (the state parameters come from the built-in table for all C-states). * Otherwise (i.e. the driver does not recognized the given processor), C-state definitions will be based on the _CST data. See https://www.kernel.org/doc/html/latest/admin-guide/pm/intel_idle.html for details. > - Any pros and cons of using the tables of _CST in firmware and embedded one in the kernel? Both can be used at the same time (see above). The built-in table in the kernel must be suitable for all of the platforms shipped with the given processor (SoC). Obviously, the _CST table allows intel_idle to work if the processor included in the platform is not recognized by it. Generally, our planned strategy is to provide built-in C-state tables for all new "mainstream" processors with the use_acpi flag set to avoid enabling C-states that may have not been validated on a given platform by default. > - Can the table in _CST archive more optimal idle states management? Possibly, but not likely. > If there is already any reference, documents I missed, kindly enlighten me then I would like to read it first before refining the questions. See above. :-) Thanks!
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index d55606608ac8..05bce595fafe 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -1067,6 +1067,11 @@ static const struct idle_cpu idle_cpu_dnv = { .use_acpi = true, }; +static const struct idle_cpu idle_cpu_cml = { + .state_table = skl_cstates, + .disable_promotion_to_c1e = true, +}; + static const struct x86_cpu_id intel_idle_ids[] __initconst = { INTEL_CPU_FAM6(NEHALEM_EP, idle_cpu_nhx), INTEL_CPU_FAM6(NEHALEM, idle_cpu_nehalem), @@ -1105,6 +1110,8 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = { INTEL_CPU_FAM6(ATOM_GOLDMONT_PLUS, idle_cpu_bxt), INTEL_CPU_FAM6(ATOM_GOLDMONT_D, idle_cpu_dnv), INTEL_CPU_FAM6(ATOM_TREMONT_D, idle_cpu_dnv), + INTEL_CPU_FAM6(COMETLAKE_L, idle_cpu_cml), + INTEL_CPU_FAM6(COMETLAKE, idle_cpu_cml), {} };
Add a general C-state table in order to support Comet Lake. Signed-off-by: Harry Pan <harry.pan@intel.com> --- drivers/idle/intel_idle.c | 7 +++++++ 1 file changed, 7 insertions(+)