ARM: 5909/1: ARM: Correct the FPSCR bits setting when raising exceptions

Commit c98929c removed the clearing of the FPSCR[31:28] bits from the vfp_raise_exceptions() function and the new bits are or'ed with the old FPSCR bits leading to unexpected results (the original commit was referring to the cumulative bits - FPSCR[4:0]). Reported-by: Tom Hameenanttila <[email protected]> Signed-off-by: Catalin Marinas <[email protected]> Signed-off-by: Russell King <[email protected]>
akeromi · Feb 1, 2010 · dbead40 · dbead40
1 parent c540b9f
commit dbead40
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
@@ -197,10 +197,13 @@ static void vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr, struct pt_
 	}
 
 	/*
-	 * Update the FPSCR with the additional exception flags.
+	 * If any of the status flags are set, update the FPSCR.
 	 * Comparison instructions always return at least one of
 	 * these flags set.
 	 */
+	if (exceptions & (FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V))
+		fpscr &= ~(FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V);
+
 	fpscr |= exceptions;
 
 	fmxr(FPSCR, fpscr);