From af93189d4ebc7851eb387145d0ea8db52698308e Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 22 Nov 2016 09:05:59 -0200 Subject: [PATCH] [media] ti-vpe: get rid of some smatch warnings When compiled on i386, it produces several warnings: ./arch/x86/include/asm/bitops.h:457:22: warning: asm output is not an lvalue ./arch/x86/include/asm/bitops.h:457:22: warning: asm output is not an lvalue ./arch/x86/include/asm/bitops.h:457:22: warning: asm output is not an lvalue ./arch/x86/include/asm/bitops.h:457:22: warning: asm output is not an lvalue ./arch/x86/include/asm/bitops.h:457:22: warning: asm output is not an lvalue ./arch/x86/include/asm/bitops.h:457:22: warning: asm output is not an lvalue I suspect that some gcc optimization could be causing the asm code to be incorrectly generated. Splitting it into two macro calls fix the issues and gets us rid of 6 smatch warnings, with is a good thing. As it should not cause any troubles, as we're basically doing the same thing, let's apply such change to vpe.c. Cc: Benoit Parrot Cc: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/ti-vpe/vpe.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/media/platform/ti-vpe/vpe.c b/drivers/media/platform/ti-vpe/vpe.c index 0626593..f0156b7 100644 --- a/drivers/media/platform/ti-vpe/vpe.c +++ b/drivers/media/platform/ti-vpe/vpe.c @@ -1615,20 +1615,32 @@ static int __vpe_try_fmt(struct vpe_ctx *ctx, struct v4l2_format *f, */ depth_bytes = depth >> 3; - if (depth_bytes == 3) + if (depth_bytes == 3) { /* * if bpp is 3(as in some RGB formats), the pixel width doesn't * really help in ensuring line stride is 16 byte aligned */ w_align = 4; - else + } else { /* * for the remainder bpp(4, 2 and 1), the pixel width alignment * can ensure a line stride alignment of 16 bytes. For example, * if bpp is 2, then the line stride can be 16 byte aligned if * the width is 8 byte aligned */ - w_align = order_base_2(VPDMA_DESC_ALIGN / depth_bytes); + + /* + * HACK: using order_base_2() here causes lots of asm output + * errors with smatch, on i386: + * ./arch/x86/include/asm/bitops.h:457:22: + * warning: asm output is not an lvalue + * Perhaps some gcc optimization is doing the wrong thing + * there. + * Let's get rid of them by doing the calculus on two steps + */ + w_align = roundup_pow_of_two(VPDMA_DESC_ALIGN / depth_bytes); + w_align = ilog2(w_align); + } v4l_bound_align_image(&pix->width, MIN_W, MAX_W, w_align, &pix->height, MIN_H, MAX_H, H_ALIGN, -- 2.7.4