From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.14 050/123] cpufreq: acpi-cpufreq: Report if CPU doesn't support boost technologies Date: Wed, 27 Mar 2019 14:15:14 -0400 Message-ID: <20190327181628.15899-50-sashal@kernel.org> References: <20190327181628.15899-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190327181628.15899-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Erwan Velu , Erwan Velu , "Rafael J . Wysocki" , Sasha Levin , linux-pm@vger.kernel.org List-Id: linux-pm@vger.kernel.org From: Erwan Velu [ Upstream commit 1222d527f314c86a3b59a522115d62facc5a7965 ] There is some rare cases where CPB (and possibly IDA) are missing on processors. This is the case fixed by commit f7f3dc00f612 ("x86/cpu/AMD: Fix erratum 1076 (CPB bit)") and following. In such context, the boost status isn't reported by /sys/devices/system/cpu/cpufreq/boost. This commit is about printing a message to report that the CPU doesn't expose the boost capabilities. This message could help debugging platforms hit by this phenomena. Signed-off-by: Erwan Velu [ rjw: Change the message text somewhat ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/cpufreq/acpi-cpufreq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index d0c34df0529c..51a3c15ace09 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -909,8 +909,10 @@ static void __init acpi_cpufreq_boost_init(void) { int ret; - if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA))) + if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA))) { + pr_debug("Boost capabilities not present in the processor\n"); return; + } acpi_cpufreq_driver.set_boost = set_boost; acpi_cpufreq_driver.boost_enabled = boost_state(0); -- 2.19.1