[v7,2/2] cpufreq: intel_pstate: Fix the FSB feq for Airmont

Commit Message

plongepe Oct. 26, 2015, 9:32 a.m. UTC

From: longepe <[e-mail]>

Include the Airmont support in the get_scaling function.

Signed-off-by: longepe <[e-mail]>
Signed-off-by: Philippe Longepe <[e-mail]>
---
 drivers/cpufreq/intel_pstate.c | 56 +++++++++++++++++++++++++++++++++---------
 1 file changed, 45 insertions(+), 11 deletions(-)

Comments

Rafael J. Wysocki Oct. 26, 2015, 11:56 p.m. UTC | #1

On Mon, Oct 26, 2015 at 10:32 AM, Philippe Longepe
<[e-mail]> wrote:
> From: longepe <[e-mail]>

Please fix this tag.

> Include the Airmont support in the get_scaling function.

The patch is doing more that this.

> Signed-off-by: longepe <[e-mail]>
> Signed-off-by: Philippe Longepe <[e-mail]>
> ---
>  drivers/cpufreq/intel_pstate.c | 56 +++++++++++++++++++++++++++++++++---------
>  1 file changed, 45 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 8618b02..4cdf97a 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -551,20 +551,35 @@ static void atom_set_pstate(struct cpudata *cpudata, int pstate)
>         wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
>  }
>
> -#define ATOM_BCLK_FREQS 5
> -static int atom_freq_table[ATOM_BCLK_FREQS] = { 833, 1000, 1333, 1167, 800};
> -
> -static int atom_get_scaling(void)
> +static int silvermont_get_scaling(void)

So the changelog should say something like

"There are two flavors of Atom cores to be supported by intel_pstate,
Silvermont and Airmont, so make the driver distinguish between them by
adding separate frequency tables etc for each of them and matching the
CPU IDs against them as appropriate."

Thanks,
Rafael
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to [e-mail]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 8618b02..4cdf97a 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -551,20 +551,35 @@  static void atom_set_pstate(struct cpudata *cpudata, int pstate)
 	wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val);
 }
 
-#define ATOM_BCLK_FREQS 5
-static int atom_freq_table[ATOM_BCLK_FREQS] = { 833, 1000, 1333, 1167, 800};
-
-static int atom_get_scaling(void)
+static int silvermont_get_scaling(void)
 {
 	u64 value;
 	int i;
+	/* Defined in Table 35-6 from SDM (Sept 2015) */
+	static int silvermont_freq_table[] = {
+		83300, 100000, 133300, 116700, 80000};
 
 	rdmsrl(MSR_FSB_FREQ, value);
-	i = value & 0x3;
+	i = value & 0x7;
+	BUG_ON(i > 4);
 
-	BUG_ON(i > ATOM_BCLK_FREQS);
+	return silvermont_freq_table[i];
+}
 
-	return atom_freq_table[i] * 100;
+static int airmont_get_scaling(void)
+{
+	u64 value;
+	int i;
+	/* Defined in Table 35-10 from SDM (Sept 2015) */
+	static int airmont_freq_table[] = {
+		83300, 100000, 133300, 116700, 80000,
+		93300, 90000, 88900, 87500};
+
+	rdmsrl(MSR_FSB_FREQ, value);
+	i = value & 0xF;
+	BUG_ON(i > 8);
+
+	return airmont_freq_table[i];
 }
 
 static void atom_get_vid(struct cpudata *cpudata)
@@ -659,7 +674,26 @@  static struct cpu_defaults core_params = {
 	},
 };
 
-static struct cpu_defaults atom_params = {
+static struct cpu_defaults silvermont_params = {
+	.pid_policy = {
+		.sample_rate_ms = 10,
+		.deadband = 0,
+		.setpoint = 60,
+		.p_gain_pct = 14,
+		.d_gain_pct = 0,
+		.i_gain_pct = 4,
+	},
+	.funcs = {
+		.get_max = atom_get_max_pstate,
+		.get_min = atom_get_min_pstate,
+		.get_turbo = atom_get_turbo_pstate,
+		.set = atom_set_pstate,
+		.get_scaling = silvermont_get_scaling,
+		.get_vid = atom_get_vid,
+	},
+};
+
+static struct cpu_defaults airmont_params = {
 	.pid_policy = {
 		.sample_rate_ms = 10,
 		.deadband = 0,
@@ -673,7 +707,7 @@  static struct cpu_defaults atom_params = {
 		.get_min = atom_get_min_pstate,
 		.get_turbo = atom_get_turbo_pstate,
 		.set = atom_set_pstate,
-		.get_scaling = atom_get_scaling,
+		.get_scaling = airmont_get_scaling,
 		.get_vid = atom_get_vid,
 	},
 };
@@ -912,7 +946,7 @@  static void intel_pstate_timer_func(unsigned long __data)
 static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
 	ICPU(0x2a, core_params),
 	ICPU(0x2d, core_params),
-	ICPU(0x37, atom_params),
+	ICPU(0x37, silvermont_params),
 	ICPU(0x3a, core_params),
 	ICPU(0x3c, core_params),
 	ICPU(0x3d, core_params),
@@ -921,7 +955,7 @@  static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
 	ICPU(0x45, core_params),
 	ICPU(0x46, core_params),
 	ICPU(0x47, core_params),
-	ICPU(0x4c, atom_params),
+	ICPU(0x4c, airmont_params),
 	ICPU(0x4e, core_params),
 	ICPU(0x4f, core_params),
 	ICPU(0x5e, core_params),