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 <robdclark@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index b3a947863ac7bb7e38d47b7a640d698b55a34bbc..6c33eaf879ae569c61b3deccba3e222b05b3494c 100644 (file)
--- 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
 
        /*