From 589bab6bb30c8cd43a7da6dcf43cc3a586cc2e25 Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Fri, 12 Jun 2020 11:09:57 -0700 Subject: [PATCH] cpufreq: intel_pstate: Add one more OOB control bit Add one more bit for OOB (Out Of Band) enabling of P-states. If OOB handling of P-states is enabled, intel_pstate shouldn't load. Currently, only "BIT(8) == 1" of the MSR MSR_MISC_PWR_MGMT is considered as OOB, but "BIT(18) == 1" needs to be taken into consideration as OOB condition too. Signed-off-by: Srinivas Pandruvada [ rjw: Add an empty code line, edit subject and changelog ] Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 8e23a698ce04..e771e8b4f99f 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2677,6 +2677,8 @@ static struct acpi_platform_list plat_info[] __initdata = { { } /* End */ }; +#define BITMASK_OOB (BIT(8) | BIT(18)) + static bool __init intel_pstate_platform_pwr_mgmt_exists(void) { const struct x86_cpu_id *id; @@ -2686,8 +2688,9 @@ static bool __init intel_pstate_platform_pwr_mgmt_exists(void) id = x86_match_cpu(intel_pstate_cpu_oob_ids); if (id) { rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr); - if (misc_pwr & (1 << 8)) { - pr_debug("Bit 8 in the MISC_PWR_MGMT MSR set\n"); + if (misc_pwr & BITMASK_OOB) { + pr_debug("Bit 8 or 18 in the MISC_PWR_MGMT MSR set\n"); + pr_debug("P states are controlled in Out of Band mode by the firmware/hardware\n"); return true; } }