From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pali =?utf-8?B?Um9ow6Fy?= Date: Tue, 18 Aug 2015 14:00:02 +0000 Subject: Re: omapdss: Division by zero in kernel Message-Id: <20150818140002.GU32236@pali> List-Id: References: <201507241803.42891@pali> <20150728115602.GL13765@pali> In-Reply-To: <20150728115602.GL13765@pali> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Tomi Valkeinen , Jean-Christophe Plagniol-Villard , Jyri Sarha Cc: linux-omap@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pavel Machek , Sebastian Reichel , Aaro Koskinen , Tony Lindgren , Nishanth Menon On Tuesday 28 July 2015 13:56:02 Pali Rohár wrote: > On Friday 24 July 2015 18:03:42 Pali Rohár wrote: > > Hello, > > > > when on N900 (real HW or qemu) I run this command > > > > / # echo 0 > /sys/devices/platform/omapdss/overlay0/enabled && echo 0 > /sys/class/graphics/fb0/size > > > > then kernel crash with this error message > > > > / # [ 29.904113] Division by zero in kernel. > > ** 3375 printk messages dropped ** [ 29.963836] [] (__aeabi_uidivmod) from [] > > (cfb_imageblit+0xac/0x464) > > ** 8426 printk messages dropped ** [ 30.111083] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 8380 printk messages dropped ** [ 30.258209] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 7813 printk messages dropped ** [ 30.400054] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 7666 printk messages dropped ** [ 30.538391] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 7687 printk messages dropped ** [ 30.676544] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 7960 printk messages dropped ** [ 30.819915] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 8317 printk messages dropped ** [ 30.966979] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 8590 printk messages dropped ** [ 31.122528] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 8885 printk messages dropped ** [ 31.287658] [] (fbcon_scroll) from [] (scrup+0x60/0x128) > > ** 9408 printk messages dropped ** [ 31.461425] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 9787 printk messages dropped ** [ 31.644287] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 10081 printk messages dropped ** [ 31.833984] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 10501 printk messages dropped ** [ 32.031066] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 10816 printk messages dropped ** [ 32.233001] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 10900 printk messages dropped ** [ 32.440490] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 10837 printk messages dropped ** [ 32.645233] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 10837 printk messages dropped ** [ 32.848999] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 10837 printk messages dropped ** [ 33.053833] [] (fbcon_redraw.isra.12) from [] > > (fbcon_scroll+0x6a0/0xcbc) > > ** 10838 printk messages dropped ** [ 33.258361] [] (fbcon_scroll) from [] (scrup+0x60/0x128) > > > > I suspect that problem is in omapdss. > > > > I do not know if size 0 make sense, but Maemo userspace is calling above > > commands and on Nokia's 2.6.28 kernel there is no crash or error message. > > > > IMHO Division by zero in kernel should not be there even if userspace > > call "incorrect" command. > > > > PING! Any idea what to do with Division by zero in kernel? > PING again! Can somebody look at this Division by zero in kernel? -- Pali Rohár pali.rohar@gmail.com