[CPUFREQ] acpi-cpufreq: Proper ReadModifyWrite of PERF_CTL MSR
During recent acpi-cpufreq changes, writing to PERF_CTL msr
changed from RMW of entire 64 bit to RMW of low 32 bit and clearing of
upper 32 bit. Fix it back to do a proper RMW of the MSR.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
index 10baa35..18c8b67 100644
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -167,11 +167,13 @@
static void do_drv_write(struct drv_cmd *cmd)
{
- u32 h = 0;
+ u32 lo, hi;
switch (cmd->type) {
case SYSTEM_INTEL_MSR_CAPABLE:
- wrmsr(cmd->addr.msr.reg, cmd->val, h);
+ rdmsr(cmd->addr.msr.reg, lo, hi);
+ lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
+ wrmsr(cmd->addr.msr.reg, lo, hi);
break;
case SYSTEM_IO_CAPABLE:
acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
@@ -372,7 +374,6 @@
struct cpufreq_freqs freqs;
cpumask_t online_policy_cpus;
struct drv_cmd cmd;
- unsigned int msr;
unsigned int next_state = 0; /* Index into freq_table */
unsigned int next_perf_state = 0; /* Index into perf table */
unsigned int i;
@@ -417,11 +418,7 @@
case SYSTEM_INTEL_MSR_CAPABLE:
cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
- msr =
- (u32) perf->states[next_perf_state].
- control & INTEL_MSR_RANGE;
- cmd.val = get_cur_val(online_policy_cpus);
- cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
+ cmd.val = (u32) perf->states[next_perf_state].control;
break;
case SYSTEM_IO_CAPABLE:
cmd.type = SYSTEM_IO_CAPABLE;
