| Message ID | 20190322224520.6740-2-srinivas.pandruvada@linux.intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Correct the processing for base_frequency | expand |
On Fri, Mar 22, 2019 at 11:45 PM Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote: > > As per ACPI specification "Guaranteed Performance Register" is a "Buffer" > field. It can't be "Integer" field. So treat "Integer" type as invalid and > ignore "Guaranteed Performance Register". > Also save one cpc_read() call, when "Guaranteed Performance Register" is > not present, which means register defined as: > "Register(SystemMemory, 0, 0, 0, 0)". > > Fixes: 29523f095397 ("ACPI / CPPC: Add support for guaranteed performance") > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > Cc: 4.20+ <stable@vger.kernel.org> # 4.20+ > --- > drivers/acpi/cppc_acpi.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c > index 1b207fca1420..3f6c290e06af 100644 > --- a/drivers/acpi/cppc_acpi.c > +++ b/drivers/acpi/cppc_acpi.c > @@ -1150,8 +1150,14 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) > cpc_read(cpunum, nominal_reg, &nom); > perf_caps->nominal_perf = nom; > > - cpc_read(cpunum, guaranteed_reg, &guaranteed); > - perf_caps->guaranteed_perf = guaranteed; > + if (guaranteed_reg->type == ACPI_TYPE_INTEGER || > + (guaranteed_reg->type == ACPI_TYPE_BUFFER && > + IS_NULL_REG(&guaranteed_reg->cpc_entry.reg))) { AFAICS anything different from a buffer should be rejected here, so why don't you do if (guaranteed_reg->type != ACPI_TYPE_BUFFER || IS_NULL_REG(&guaranteed_reg->cpc_entry.reg)) > + perf_caps->guaranteed_perf = 0; > + } else { > + cpc_read(cpunum, guaranteed_reg, &guaranteed); > + perf_caps->guaranteed_perf = guaranteed; > + } > > cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear); > perf_caps->lowest_nonlinear_perf = min_nonlinear; > -- > 2.17.2 >
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 1b207fca1420..3f6c290e06af 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1150,8 +1150,14 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) cpc_read(cpunum, nominal_reg, &nom); perf_caps->nominal_perf = nom; - cpc_read(cpunum, guaranteed_reg, &guaranteed); - perf_caps->guaranteed_perf = guaranteed; + if (guaranteed_reg->type == ACPI_TYPE_INTEGER || + (guaranteed_reg->type == ACPI_TYPE_BUFFER && + IS_NULL_REG(&guaranteed_reg->cpc_entry.reg))) { + perf_caps->guaranteed_perf = 0; + } else { + cpc_read(cpunum, guaranteed_reg, &guaranteed); + perf_caps->guaranteed_perf = guaranteed; + } cpc_read(cpunum, lowest_non_linear_reg, &min_nonlinear); perf_caps->lowest_nonlinear_perf = min_nonlinear;
As per ACPI specification "Guaranteed Performance Register" is a "Buffer" field. It can't be "Integer" field. So treat "Integer" type as invalid and ignore "Guaranteed Performance Register". Also save one cpc_read() call, when "Guaranteed Performance Register" is not present, which means register defined as: "Register(SystemMemory, 0, 0, 0, 0)". Fixes: 29523f095397 ("ACPI / CPPC: Add support for guaranteed performance") Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: 4.20+ <stable@vger.kernel.org> # 4.20+ --- drivers/acpi/cppc_acpi.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)