[PATCH 2.5.54] cpufreq: p4-clockmod bugfixes

From: Dominik Brodowski (linux@brodo.de)
Date: Mon Jan 06 2003 - 08:49:35 EST


The "get current speed" algorithm wasn't aware of the disable/enable bit,
and the policy verification function wasn't aware of the N44 / O17
bug. Also, some unused code is removed.

 arch/i386/kernel/cpu/cpufreq/p4-clockmod.c | 90 +++++++++++++++--------------
 1 files changed, 49 insertions(+), 41 deletions(-)

diff -ruN linux-original/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c linux/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c
--- linux-original/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c 2003-01-06 12:55:49.000000000 +0100
+++ linux/arch/i386/kernel/cpu/cpufreq/p4-clockmod.c 2003-01-06 13:13:19.000000000 +0100
@@ -82,12 +82,17 @@
 
         /* get current state */
         rdmsr(MSR_IA32_THERM_CONTROL, l, h);
- l = l >> 1;
- l &= 0x7;
-
+ if (l & 0x10) {
+ l = l >> 1;
+ l &= 0x7;
+ } else
+ l = DC_DISABLE;
+
         if (l == newstate) {
                 set_cpus_allowed(current, cpus_allowed);
                 return 0;
+ } else if (l == DC_RESV) {
+ printk(KERN_ERR PFX "BIG FAT WARNING: currently in invalid setting\n");
         }
 
         /* notifiers */
@@ -141,13 +146,18 @@
         unsigned int i;
         unsigned int newstate = 0;
         unsigned int number_states = 0;
+ unsigned int minstate = 1;
 
- if (!cpufreq_p4_driver || !stock_freq || !policy)
+ if (!cpufreq_p4_driver || !stock_freq ||
+ !policy || !cpu_online(policy->cpu))
                 return -EINVAL;
 
+ if (has_N44_O17_errata)
+ minstate = 3;
+
         if (policy->policy == CPUFREQ_POLICY_POWERSAVE)
         {
- for (i=8; i>0; i--)
+ for (i=8; i>=minstate; i--)
                         if ((policy->min <= ((stock_freq / 8) * i)) &&
                             (policy->max >= ((stock_freq / 8) * i)))
                         {
@@ -155,7 +165,7 @@
                                 number_states++;
                         }
         } else {
- for (i=1; i<=8; i++)
+ for (i=minstate; i<=8; i++)
                         if ((policy->min <= ((stock_freq / 8) * i)) &&
                             (policy->max >= ((stock_freq / 8) * i)))
                         {
@@ -164,25 +174,8 @@
                         }
         }
 
- /* if (number_states == 1) */
- {
- if (policy->cpu == CPUFREQ_ALL_CPUS) {
- for (i=0; i<NR_CPUS; i++)
- if (cpu_online(i))
- cpufreq_p4_setdc(i, newstate);
- } else {
- cpufreq_p4_setdc(policy->cpu, newstate);
- }
- }
- /* else {
- if (policy->policy == CPUFREQ_POLICY_POWERSAVE) {
- min_state = newstate;
- max_state = newstate + (number_states - 1);
- } else {
- max_state = newstate;
- min_state = newstate - (number_states - 1);
- }
- } */
+ cpufreq_p4_setdc(policy->cpu, newstate);
+
         return 0;
 }
 
@@ -190,17 +183,21 @@
 static int cpufreq_p4_verify(struct cpufreq_policy *policy)
 {
         unsigned int number_states = 0;
- unsigned int i;
+ unsigned int i = 1;
 
- if (!cpufreq_p4_driver || !stock_freq || !policy)
+ if (!cpufreq_p4_driver || !stock_freq ||
+ !policy || !cpu_online(policy->cpu))
                 return -EINVAL;
 
- if (!cpu_online(policy->cpu))
- policy->cpu = CPUFREQ_ALL_CPUS;
- cpufreq_verify_within_limits(policy, (stock_freq / 8), stock_freq);
+ cpufreq_verify_within_limits(policy,
+ policy->cpuinfo.min_freq,
+ policy->cpuinfo.max_freq);
 
- /* is there at least one state within limit? */
- for (i=1; i<=8; i++)
+ if (has_N44_O17_errata)
+ i = 3;
+
+ /* is there at least one state within the limit? */
+ for (; i<=8; i++)
                 if ((policy->min <= ((stock_freq / 8) * i)) &&
                     (policy->max >= ((stock_freq / 8) * i)))
                         number_states++;
@@ -209,11 +206,14 @@
                 return 0;
 
         policy->max = (stock_freq / 8) * (((unsigned int) ((policy->max * 8) / stock_freq)) + 1);
+ cpufreq_verify_within_limits(policy,
+ policy->cpuinfo.min_freq,
+ policy->cpuinfo.max_freq);
         return 0;
 }
 
 
-int __init cpufreq_p4_init(void)
+static int __init cpufreq_p4_init(void)
 {
         struct cpuinfo_x86 *c = cpu_data;
         int cpuid;
@@ -245,6 +245,16 @@
         }
 
         printk(KERN_INFO PFX "P4/Xeon(TM) CPU On-Demand Clock Modulation available\n");
+
+ if (!stock_freq) {
+ if (cpu_khz)
+ stock_freq = cpu_khz;
+ else {
+ printk(KERN_INFO PFX "unknown core frequency - please use module parameter 'stock_freq'\n");
+ return -EINVAL;
+ }
+ }
+
         driver = kmalloc(sizeof(struct cpufreq_driver) +
                          NR_CPUS * sizeof(struct cpufreq_policy), GFP_KERNEL);
         if (!driver)
@@ -252,9 +262,6 @@
 
         driver->policy = (struct cpufreq_policy *) (driver + 1);
 
- if (!stock_freq)
- stock_freq = cpu_khz;
-
 #ifdef CONFIG_CPU_FREQ_24_API
         for (i=0;i<NR_CPUS;i++) {
                 driver->cpu_cur_freq[i] = stock_freq;
@@ -290,15 +297,16 @@
 }
 
 
-void __exit cpufreq_p4_exit(void)
+static void __exit cpufreq_p4_exit(void)
 {
- u32 l, h;
+ unsigned int i;
 
         if (cpufreq_p4_driver) {
+ for (i=0; i<NR_CPUS; i++) {
+ if (cpu_online(i))
+ cpufreq_p4_setdc(i, DC_DISABLE);
+ }
                 cpufreq_unregister();
- /* return back to a non modulated state */
- rdmsr(MSR_IA32_THERM_CONTROL, l, h);
- wrmsr(MSR_IA32_THERM_CONTROL, l & ~(1<<4), h);
                 kfree(cpufreq_p4_driver);
         }
 }
-
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This archive was generated by hypermail 2b29 : Tue Jan 07 2003 - 22:00:31 EST