From c1cbabe8ae5702a1e54d62401fe3b58a84fcb3e4 Mon Sep 17 00:00:00 2001 From: Val Packett Date: Sat, 17 Jun 2023 13:29:53 -0300 Subject: [PATCH] amdtemp: Fix missing 49 degree offset on current EPYC CPUs On an EPYC 7313P, the temperature reported by amdtemp was off, because the offset was not applied. Turns out it needs to be applied with one more condition: https://lkml.org/lkml/2023/4/13/1095 Reviewed by: mhorne Tested by: mike.jakubik@gmail.com MFC after: 1 week Sponsored by: https://www.patreon.com/valpackett Pull Request: https://github.com/freebsd/freebsd-src/pull/754 --- sys/dev/amdtemp/amdtemp.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/sys/dev/amdtemp/amdtemp.c b/sys/dev/amdtemp/amdtemp.c index c020d481797..fa58a3a4fc8 100644 --- a/sys/dev/amdtemp/amdtemp.c +++ b/sys/dev/amdtemp/amdtemp.c @@ -165,6 +165,12 @@ static const struct amdtemp_product { */ #define AMDTEMP_17H_CUR_TMP 0x59800 #define AMDTEMP_17H_CUR_TMP_RANGE_SEL (1u << 19) +/* + * Bits 16-17, when set, mean that CUR_TMP is read-write. When it is, the + * 49 degree offset should apply as well. This was revealed in a Linux + * patch from an AMD employee. + */ +#define AMDTEMP_17H_CUR_TMP_TJ_SEL ((1u << 17) | (1u << 16)) /* * The following register set was discovered experimentally by Ondrej Čerman * and collaborators, but is not (yet) documented in a PPR/OSRR (other than @@ -731,7 +737,8 @@ amdtemp_decode_fam17h_tctl(int32_t sc_offset, uint32_t val) { bool minus49; - minus49 = ((val & AMDTEMP_17H_CUR_TMP_RANGE_SEL) != 0); + minus49 = ((val & AMDTEMP_17H_CUR_TMP_RANGE_SEL) != 0) + || ((val & AMDTEMP_17H_CUR_TMP_TJ_SEL) == AMDTEMP_17H_CUR_TMP_TJ_SEL); return (amdtemp_decode_fam10h_to_17h(sc_offset, val >> AMDTEMP_REPTMP10H_CURTMP_SHIFT, minus49)); }