Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751947AbaBTVHO (ORCPT ); Thu, 20 Feb 2014 16:07:14 -0500 Received: from mail-oa0-f41.google.com ([209.85.219.41]:64069 "EHLO mail-oa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751286AbaBTVHM (ORCPT ); Thu, 20 Feb 2014 16:07:12 -0500 MIME-Version: 1.0 In-Reply-To: <1392930177.15264.5.camel@x220> References: <1391085212.5170.9.camel@x41> <1392930177.15264.5.camel@x220> Date: Thu, 20 Feb 2014 16:07:11 -0500 X-Google-Sender-Auth: YKqIhS_pbo861z6FvSW1Xc6Dtoo Message-ID: Subject: Re: [PATCH] drm/radeon: silence GCC warning on 32 bit From: Ilia Mirkin To: Paul Bolle Cc: Dave Airlie , =?ISO-8859-1?Q?Christian_K=F6nig?= , Alex Deucher , "dri-devel@lists.freedesktop.org" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 20, 2014 at 4:02 PM, Paul Bolle wrote: > Building radeon_ttm.o on 32 bit x86 triggers a warning: > In file included from include/asm-generic/bug.h:13:0, > from [...]/arch/x86/include/asm/bug.h:38, > from include/linux/bug.h:4, > from include/drm/drm_mm.h:39, > from include/drm/drm_vma_manager.h:26, > from include/drm/ttm/ttm_bo_api.h:35, > from drivers/gpu/drm/radeon/radeon_ttm.c:32: > drivers/gpu/drm/radeon/radeon_ttm.c: In function 'radeon_ttm_gtt_read': > include/linux/kernel.h:712:17: warning: comparison of distinct pointer types lacks a cast [enabled by default] > (void) (&_min1 == &_min2); \ > ^ > drivers/gpu/drm/radeon/radeon_ttm.c:938:22: note: in expansion of macro 'min' > ssize_t cur_size = min(size, PAGE_SIZE - off); > ^ > > Silence this warning by casting "PAGE_SIZE - off" to size_t. Since > "PAGE_SIZE - off" is between 0 and PAGE_SIZE, and PAGE_SIZE is at most > 21 bits wide while size_t is at least 32 bits wide, this should be safe. > > Signed-off-by: Paul Bolle > --- > Compile tested only (on 32 and 64 bit x86). > > drivers/gpu/drm/radeon/radeon_ttm.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c > index 77f5b0c..5c87979 100644 > --- a/drivers/gpu/drm/radeon/radeon_ttm.c > +++ b/drivers/gpu/drm/radeon/radeon_ttm.c > @@ -935,7 +935,7 @@ static ssize_t radeon_ttm_gtt_read(struct file *f, char __user *buf, > while (size) { > loff_t p = *pos / PAGE_SIZE; > unsigned off = *pos & ~PAGE_MASK; > - ssize_t cur_size = min(size, PAGE_SIZE - off); > + ssize_t cur_size = min(size, (size_t)(PAGE_SIZE - off)); Isn't the usual way of dealing with these to do something like ssize_t cur_size = min_t(ssize_t, size, PAGE_SIZE - off) > struct page *page; > void *ptr; > > -- > 1.8.5.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/