Files
lbmk/config/coreboot/dell/patches/0016-fix-speedstep-on-x200-t400-Revert-cpu-intel-model_10.patch
T
Leah Rowe 742c00331e coreboot/dell: move e6400 to new tree, dell
the ddr2 fix broke *ddr3* on gm45 thinkpads in
testing, depending on memory modules. this was
established by removing patches, re-doing
configs etc, on a user's X200 (testing gentoo
and freebsd). the X200 kept randomly rebooting
or having random glitches.

the configs themselves (gm45 thinkpads) will
also be re-done, because i found minor issues
unrelated, but this patch moves dell e6400 to
its own tree. the ddr2 fix is no longer present
in coreboot/default, only coreboot/dell.

i noticed minor differences in gm45 thinkpad
configs, when re-doing the configs, versus
what are currently in lbmk master; for instance,
vbt was not enabled anymore, on thinkpad x200.
modifications to these will be done separately.

Signed-off-by: Leah Rowe <leah@libreboot.org>
2023-11-05 12:23:42 +00:00

48 lines
1.7 KiB
Diff

From 3ec06fa2393995b87af1dbc0387c5d3255d5c0db Mon Sep 17 00:00:00 2001
From: Leah Rowe <leah@libreboot.org>
Date: Wed, 1 Dec 2021 02:53:00 +0000
Subject: [PATCH 16/22] fix speedstep on x200/t400: Revert
"cpu/intel/model_1067x: enable PECI"
This reverts commit 70fea013c7ebd6d85a7806748233fcfd76802f5f.
Enabling PECI without microcode updates loaded causes the CPUID feature set
to become corrupted. And one consequence is broken SpeedStep. At least, that's
my understanding looking at Intel Errata. This revert is not a fix, because
upstream is correct (upstream assumes microcode updates). We will simply
maintain this revert patch in Libreboot, from now on.
---
src/cpu/intel/model_1067x/model_1067x_init.c | 9 ---------
1 file changed, 9 deletions(-)
diff --git a/src/cpu/intel/model_1067x/model_1067x_init.c b/src/cpu/intel/model_1067x/model_1067x_init.c
index 315e7c36fc..1423fd72bc 100644
--- a/src/cpu/intel/model_1067x/model_1067x_init.c
+++ b/src/cpu/intel/model_1067x/model_1067x_init.c
@@ -141,8 +141,6 @@ static void configure_emttm_tables(void)
wrmsr(MSR_EMTTM_CR_TABLE(5), msr);
}
-#define IA32_PECI_CTL 0x5a0
-
static void configure_misc(const int eist, const int tm2, const int emttm)
{
msr_t msr;
@@ -185,13 +183,6 @@ static void configure_misc(const int eist, const int tm2, const int emttm)
msr.lo |= (1 << 20); /* Lock Enhanced SpeedStep Enable */
wrmsr(IA32_MISC_ENABLE, msr);
}
-
- /* Enable PECI
- WARNING: due to Erratum AW67 described in Intel document #318733
- the microcode must be updated before this MSR is written to. */
- msr = rdmsr(IA32_PECI_CTL);
- msr.lo |= 1;
- wrmsr(IA32_PECI_CTL, msr);
}
#define PIC_SENS_CFG 0x1aa
--
2.39.2