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| author | Venki Pallipadi <venkatesh.pallipadi@intel.com> | 2007-07-16 16:57:38 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-08-09 14:27:40 -0700 |
| commit | 5f170d5e5e4c497d89ae758408db0f202d446968 (patch) | |
| tree | bc0c8b54160e5a79f81b4375d7a5146df990f4c8 | |
| parent | f91ff4269eb0617b126779f7cb82e11cb0a74bd5 (diff) | |
| download | lwn-5f170d5e5e4c497d89ae758408db0f202d446968.tar.gz lwn-5f170d5e5e4c497d89ae758408db0f202d446968.zip | |
acpi-cpufreq: Proper ReadModifyWrite of PERF_CTL MSR
[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>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c index 10baa3501ed3..18c8b67ea3a7 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_read(struct drv_cmd *cmd) 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 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, 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 @@ static int acpi_cpufreq_target(struct cpufreq_policy *policy, 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; |