CPUID Fn8000_0007_EDX[CPB] is wrongly 0 on Model 17,
Stepping 0, but revision guide has not been released for
newer Family 17h models.
Tesed on AMD "Ryzen 7 2700U with Radeon Vega Mobile Gfx"
and "AMD Ryzen 5 2500U with Radeon Vega Mobile Gfx",
their CPUID Fn0000_0001_EAX is 0x00810f10 and should have
CPB feature according AMD product specifications, however
their Fn8000_0007_EDX is 0x00006599, indicating they don't
support CPB feature.
Signed-off-by: Jiaxun Yang <jiaxun.y...@flygoat.com>
---
arch/x86/kernel/cpu/amd.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index eeea634bee0a..7db43ef8e97e 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -821,8 +821,12 @@ static void init_amd_zn(struct cpuinfo_x86 *c)
/*
* Fix erratum 1076: CPB feature bit not being set in CPUID. It affects
* all up to and including B1.
+ *
+ * Revision guide for Family 17h, Model 17 has not been released, but
+ * Model 17, Stepping 0 have the same issue.
*/
- if (c->x86_model <= 1 && c->x86_stepping <= 1)
+ if ((c->x86_model <= 1 && c->x86_stepping <= 1) || \
+ (c->x86_model == 17 && c->x86_stepping == 0))
set_cpu_cap(c, X86_FEATURE_CPB);
}
--
2.19.1
