From f72d3d6b04d21a7b2ba7ba9ee551dd6f1a9b93e4 Mon Sep 17 00:00:00 2001
From: Bin Meng <bmeng.cn@gmail.com>
Date: Mon, 9 Nov 2020 15:55:49 +0800
Subject: [PATCH] x86: Avoid using hardcoded number of variable range MTRRs in
mtrr_commit()
Since commit 29d2d64ed55f ("x86: Add support for more than 8 MTRRs"),
the maximum number of variable range MTRRs was increased from 8 to 10.
On the BayTrail platform there are only 8 variable range MTRRs. In
mtrr_commit() it still uses MTRR_MAX_COUNT which caused a #GP during
VESA video driver probe. It should have been updated to use dynamically
probed number.
This fixes the boot failure seen on Intel Minnow Max board.
Fixes: 29d2d64ed55f ("x86: Add support for more than 8 MTRRs")
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
arch/x86/cpu/mtrr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/cpu/mtrr.c b/arch/x86/cpu/mtrr.c
index 5180eb06fc..6f095c53a5 100644
--- a/arch/x86/cpu/mtrr.c
+++ b/arch/x86/cpu/mtrr.c
@@ -158,7 +158,7 @@ int mtrr_commit(bool do_caches)
/* Clear the ones that are unused */
debug("clear\n");
- for (; i < MTRR_MAX_COUNT; i++)
+ for (; i < mtrr_get_var_count(); i++)
wrmsrl(MTRR_PHYS_MASK_MSR(i), 0);
debug("close\n");
mtrr_close(&state, do_caches);
--
2.39.5