mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-27 01:11:14 +00:00
62 lines
2.1 KiB
Diff
62 lines
2.1 KiB
Diff
|
From: David Woodhouse <dwmw2@infradead.org>
|
||
|
|
Date: Thu, 17 Sep 2015 10:16:54 +0100
|
||
|
|
Subject: [PATCH] x86/platform: Fix Geode LX timekeeping in the generic x86
|
||
|
|
build
|
||
|
|
|
||
|
|
In 2007, commit 07190a08eef36 ("Mark TSC on GeodeLX reliable")
|
||
|
|
bypassed verification of the TSC on Geode LX. However, this code
|
||
|
|
(now in the check_system_tsc_reliable() function in
|
||
|
|
arch/x86/kernel/tsc.c) was only present if CONFIG_MGEODE_LX was
|
||
|
|
set.
|
||
|
|
|
||
|
|
OpenWRT has recently started building its generic Geode target
|
||
|
|
for Geode GX, not LX, to include support for additional
|
||
|
|
platforms. This broke the timekeeping on LX-based devices,
|
||
|
|
because the TSC wasn't marked as reliable:
|
||
|
|
https://dev.openwrt.org/ticket/20531
|
||
|
|
|
||
|
|
By adding a runtime check on is_geode_lx(), we can also include
|
||
|
|
the fix if CONFIG_MGEODEGX1 or CONFIG_X86_GENERIC are set, thus
|
||
|
|
fixing the problem.
|
||
|
|
|
||
|
|
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
|
||
|
|
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
||
|
|
Closes #20531
|
||
|
|
---
|
||
|
|
|
||
|
|
--- a/arch/x86/kernel/tsc.c
|
||
|
|
+++ b/arch/x86/kernel/tsc.c
|
||
|
|
@@ -21,6 +21,7 @@
|
||
|
|
#include <asm/hypervisor.h>
|
||
|
|
#include <asm/nmi.h>
|
||
|
|
#include <asm/x86_init.h>
|
||
|
|
+#include <asm/geode.h>
|
||
|
|
|
||
|
|
unsigned int __read_mostly cpu_khz; /* TSC clocks / usec, not used here */
|
||
|
|
EXPORT_SYMBOL(cpu_khz);
|
||
|
|
@@ -1004,15 +1005,17 @@ EXPORT_SYMBOL_GPL(mark_tsc_unstable);
|
||
|
|
|
||
|
|
static void __init check_system_tsc_reliable(void)
|
||
|
|
{
|
||
|
|
-#ifdef CONFIG_MGEODE_LX
|
||
|
|
- /* RTSC counts during suspend */
|
||
|
|
+#if defined(CONFIG_MGEODEGX1) || defined(CONFIG_MGEODE_LX) || defined(CONFIG_X86_GENERIC)
|
||
|
|
+ if (is_geode_lx()) {
|
||
|
|
+ /* RTSC counts during suspend */
|
||
|
|
#define RTSC_SUSP 0x100
|
||
|
|
- unsigned long res_low, res_high;
|
||
|
|
+ unsigned long res_low, res_high;
|
||
|
|
|
||
|
|
- rdmsr_safe(MSR_GEODE_BUSCONT_CONF0, &res_low, &res_high);
|
||
|
|
- /* Geode_LX - the OLPC CPU has a very reliable TSC */
|
||
|
|
- if (res_low & RTSC_SUSP)
|
||
|
|
- tsc_clocksource_reliable = 1;
|
||
|
|
+ rdmsr_safe(MSR_GEODE_BUSCONT_CONF0, &res_low, &res_high);
|
||
|
|
+ /* Geode_LX - the OLPC CPU has a very reliable TSC */
|
||
|
|
+ if (res_low & RTSC_SUSP)
|
||
|
|
+ tsc_clocksource_reliable = 1;
|
||
|
|
+ }
|
||
|
|
#endif
|
||
|
|
if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE))
|
||
|
|
tsc_clocksource_reliable = 1;
|