ARM: 8196/1: vfp: Workaround bad MVFR1 register on some Kraits

Certain versions of the Krait processor don't report that they support the fused multiply accumulate instruction via the MVFR1 register despite the fact that they actually do. Unfortunately we use this register to identify support for VFPv4. Override the hwcap on all Krait processors to indicate support for VFPv4 to workaround this. Tested-by: Rob Clark <[email protected]> Signed-off-by: Stephen Boyd <[email protected]> Signed-off-by: Russell King <[email protected]>
vincehsu · Nov 21, 2014 · 6f0f2a9 · 6f0f2a9
1 parent 1ca8bf6
commit 6f0f2a9
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
@@ -593,9 +593,10 @@ __krait_proc_info:
 	/*
 	 * Some Krait processors don't indicate support for SDIV and UDIV
 	 * instructions in the ARM instruction set, even though they actually
-	 * do support them.
+	 * do support them. They also don't indicate support for fused multiply
+	 * instructions even though they actually do support them.
 	 */
-	__v7_proc __v7_setup, hwcaps = HWCAP_IDIV
+	__v7_proc __v7_setup, hwcaps = HWCAP_IDIV | HWCAP_VFPv4
 	.size	__krait_proc_info, . - __krait_proc_info
 
 	/*