git: 66d48f02de0f - main - hwpstate_intel(4): Comment the EPB to EPP computation

The branch main has been updated by olce:

URL: https://cgit.FreeBSD.org/src/commit/?id=66d48f02de0fbf4d8efb3d4edc69f37c54f130fd

commit 66d48f02de0fbf4d8efb3d4edc69f37c54f130fd
Author:     Olivier Certner <olce@FreeBSD.org>
AuthorDate: 2026-06-24 20:14:12 +0000
Commit:     Olivier Certner <olce@FreeBSD.org>
CommitDate: 2026-06-25 00:27:24 +0000

    hwpstate_intel(4): Comment the EPB to EPP computation
    
    Explain why the '* 17' instead of '* 16', as suggested in revision
    D55629.
    
    Event:          Halifax Hackathon 202606
    Location:       jrm@'s living room
    Sponsored by:   The FreeBSD Foundation
---
 sys/x86/cpufreq/hwpstate_intel.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/x86/cpufreq/hwpstate_intel.c b/sys/x86/cpufreq/hwpstate_intel.c
index b18f1b674d22..6d3100217365 100644
--- a/sys/x86/cpufreq/hwpstate_intel.c
+++ b/sys/x86/cpufreq/hwpstate_intel.c
@@ -254,6 +254,10 @@ out:
 	return (ret);
 }
 
+/*
+ * Multiplying by 17 here allows to send [0;15] to the full [0;255] range (so
+ * 255 is reported when EPB is set to 15, instead of 240).
+ */
 #define EPB_TO_EPP(x) ((x) * 17)
 #define EPP_TO_EPB(x) ((x) >> 4)