From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
To: rjw@rjwysocki.net, lenb@kernel.org, viresh.kumar@linaro.org
Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org, pprakash@codeaurora.org,
wangxiongfeng2@huawei.com,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
"4 . 20+" <stable@vger.kernel.org>
Subject: [PATCH 2/2] cpufreq: intel_pstate: Also use cppc nominal_perf for base_frequency
Date: Fri, 22 Mar 2019 15:45:20 -0700 [thread overview]
Message-ID: <20190322224520.6740-3-srinivas.pandruvada@linux.intel.com> (raw)
In-Reply-To: <20190322224520.6740-1-srinivas.pandruvada@linux.intel.com>
ACPI specifications stat that if the "Guaranteed Performance Register" is
not implemented, OSPM assumes guaranteed performance is always equal to
nominal performance. So for invalid and unimplemented guaranteed
performance register, use nominal performance as guaranteed performance.
This change will fallback to nominal_perf when guranteed_perf is invalid.
If nominal_perf is also invalid, then fallback to existing implementation,
which is to read from HWP Capabilities MSR.
Fixes: 86d333a8cc7f ("cpufreq: intel_pstate: Add base_frequency attribute")
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 4.20+ <stable@vger.kernel.org> # 4.20+
---
drivers/cpufreq/intel_pstate.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 7b4b0a7ac68b..e16dea241c55 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -385,6 +385,9 @@ static int intel_pstate_get_cppc_guranteed(int cpu)
if (ret)
return ret;
+ if (!cppc_perf.guaranteed_perf)
+ return cppc_perf.nominal_perf;
+
return cppc_perf.guaranteed_perf;
}
--
2.17.2
next prev parent reply other threads:[~2019-03-22 22:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190322224520.6740-1-srinivas.pandruvada@linux.intel.com>
2019-03-22 22:45 ` [PATCH 1/2] ACPI / CPPC: Fix processing for guaranteed performance Srinivas Pandruvada
2019-03-25 11:49 ` Rafael J. Wysocki
2019-03-22 22:45 ` Srinivas Pandruvada [this message]
2019-03-25 12:04 ` [PATCH 2/2] cpufreq: intel_pstate: Also use cppc nominal_perf for base_frequency Rafael J. Wysocki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190322224520.6740-3-srinivas.pandruvada@linux.intel.com \
--to=srinivas.pandruvada@linux.intel.com \
--cc=lenb@kernel.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=pprakash@codeaurora.org \
--cc=rjw@rjwysocki.net \
--cc=stable@vger.kernel.org \
--cc=viresh.kumar@linaro.org \
--cc=wangxiongfeng2@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).