From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Date: Tue, 03 Jul 2018 14:58:11 +0000 Subject: Re: [PATCH 18/21] udlfb: allow reallocating the framebuffer Message-Id: <5125051.fdeVNsUfGe@amdc3058> List-Id: References: <20180603144225.463043082@twibright.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Mikulas Patocka Cc: linux-fbdev@vger.kernel.org, Ladislav Michl , kbuild test robot , Bernie Thompson , dri-devel@lists.freedesktop.org, kbuild-all@01.org, Dave Airlie On Tuesday, June 12, 2018 12:32:34 PM Mikulas Patocka wrote: > > On Mon, 4 Jun 2018, kbuild test robot wrote: > > > Hi Mikulas, > > > > I love your patch! Perhaps something to improve: > > > > [auto build test WARNING on drm/drm-next] > > [also build test WARNING on v4.17-rc7 next-20180601] > > [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] > > > > url: https://github.com/0day-ci/linux/commits/Mikulas-Patocka/USB-DisplayLink-patches/20180603-233013 > > What is it really complaining about? That URL shows 404 Not Found and this > email has no warnings at all. screen_base in struct fb_info is annotated with __iomem tag: ... char __iomem *screen_base; /* Virtual address */ ... and this tag should be preserved (or explicitly casted). > > base: git://people.freedesktop.org/~airlied/linux.git drm-next > > reproduce: > > # apt-get install sparse > > make ARCH=x86_64 allmodconfig > > make C=1 CF=-D__CHECK_ENDIAN__ You should be able to reproduce the issue with the above sequence. > > sparse warnings: (new ones prefixed by >>) [...] > > 1178 u32 old_len = info->fix.smem_len; > > > 1179 unsigned char *old_fb = info->screen_base; > > 1180 unsigned char *new_fb; [...] > > 1196 if (info->screen_base) { > > 1197 memcpy(new_fb, old_fb, old_len); > > > 1198 dlfb_deferred_vfree(dlfb, info->screen_base); > > 1199 } Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics