In message <200810241247.08480.zzam@xxxxxxxxxx>, Matthias Schwarzott wrote: Hiya. >Hi! > >@Mauro: Please pull this patch >There already is an report at kernel bugzilla about this issue: >http://bugzilla.kernel.org/show_bug.cgi?id=9455 > >When enabling extra checks for the i2c-bus of cx88 based cards by >loading i2c_algo_bit with bit_test=1 this may trigger an oops >when loading cx88_dvb. > >This is caused by the extra check code that detects that the >sda-line is stuck high and thus does not register the i2c-bus. > >cx88-dvb however does not check if the i2c-bus is valid and just >uses core->i2c_adap to attach dvb frontend modules. >This leads to an oops at the first call to i2c_transfer: > ># modprobe i2c_algo_bit bit_test=1 ># modprobe cx8802 Thanks for this information. If you don't mind, would you let me utilise this fix in another way? I have been auditing MFE additions and I need to change something elsewhere and can see an alternative to to bailing out in dvb_register? Thanks >cx88/2: cx2388x MPEG-TS Driver Manager version 0.0.6 loaded >cx88[0]: quirk: PCIPCI_NATOMA -- set TBFX >cx88[0]: subsystem: 0070:9202, board: Hauppauge Nova-S-Plus DVB-S >[card=37,autodetected], frontend(s): 1 >cx88[0]: TV tuner type 4, Radio tuner type -1 >cx88[0]: SDA stuck high! >cx88[0]: i2c register FAILED >input: cx88 IR (Hauppauge Nova-S-Plus as /class/input/input5 >cx88[0]/2: cx2388x 8802 Driver Manager >cx88-mpeg driver manager 0000:00:10.2: enabling device (0154 -> 0156) >cx88-mpeg driver manager 0000:00:10.2: PCI INT A -> Link[LNKD] -> GSI 9 >(level, low) -> IRQ 9 >cx88[0]/2: found at 0000:00:10.2, rev: 5, irq: 9, latency: 64, mmio: >0xfb000000 >cx8802_probe() allocating 1 frontend(s) >cx88/2: cx2388x dvb driver version 0.0.6 loaded >cx88/2: registering cx8802 driver, type: dvb access: shared >cx88[0]/2: subsystem: 0070:9202, board: Hauppauge Nova-S-Plus DVB-S [card=37] >cx88[0]/2: cx2388x based DVB/ATSC card >BUG: unable to handle kernel NULL pointer dereference at 00000000 >IP: [<e084d4ef>] :i2c_core:i2c_transfer+0x1f/0x80 >*pde = 00000000 >Modules linked in: cx88_dvb(+) cx8802 cx88xx ir_common i2c_algo_bit tveeprom >videobuf_dvb btcx_risc >mga drm ipv6 fscpos eeprom nfsd exportfs stv0299 b2c2_flexcop_pci b2c2_flexcop >cx24123 s5h1420 ves1x93 >dvb_ttpci dvb_core saa7146_vv saa7146 videobuf_dma_sg videobuf_core videodev >v4l1_compat ttpci_eeprom >lirc_serial lirc_dev usbhid rtc uhci_hcd 8139too i2c_piix4 i2c_core usbcore >evdev >Pid: 4249, comm: modprobe Not tainted (2.6.27-gentoo #3) >EIP: 0060:[<e084d4ef>] EFLAGS: 00010296 CPU: 0 >EIP is at i2c_transfer+0x1f/0x80 [i2c_core] >EAX: 00000000 EBX: ffffffa1 ECX: 00000002 EDX: d6c71e3c >ESI: d80cd050 EDI: d8093c00 EBP: d6c71e20 ESP: d6c71e0c >DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 >---[ end trace b32d87d0f0db1832 ]--- > >I added a check for i2c registration success before attaching frontends. > >Signed-off-by: Matthias Schwarzott <zzam@xxxxxxxxxx> > >--Boundary-00=_seaAJIF74ESp9Id >Content-Type: text/x-diff; > charset="iso 8859-15"; > name="cx88-dvb-oops-i2c.diff" >Content-Transfer-Encoding: 7bit >Content-Disposition: attachment; > filename="cx88-dvb-oops-i2c.diff" > >cx88-dvb: Fix Oops in case i2c bus failed to register > >When enabling extra checks for the i2c-bus of cx88 based cards by >loading i2c_algo_bit with bit_test=1 this may trigger an oops >when loading cx88_dvb. > >This is caused by the extra check code that detects that the >sda-line is stuck high and thus does not register the i2c-bus. > >cx88-dvb however does not check if the i2c-bus is valid and just >uses core->i2c_adap to attach dvb frontend modules. >This leads to an oops at the first call to i2c_transfer: > ># modprobe i2c_algo_bit bit_test=1 ># modprobe cx8802 > >cx88/2: cx2388x MPEG-TS Driver Manager version 0.0.6 loaded >cx88[0]: quirk: PCIPCI_NATOMA -- set TBFX >cx88[0]: subsystem: 0070:9202, board: Hauppauge Nova-S-Plus DVB-S [card=37,autodetected], frontend(s): 1 >cx88[0]: TV tuner type 4, Radio tuner type -1 >cx88[0]: SDA stuck high! >cx88[0]: i2c register FAILED >input: cx88 IR (Hauppauge Nova-S-Plus as /class/input/input5 >cx88[0]/2: cx2388x 8802 Driver Manager >cx88-mpeg driver manager 0000:00:10.2: enabling device (0154 -> 0156) >cx88-mpeg driver manager 0000:00:10.2: PCI INT A -> Link[LNKD] -> GSI 9 (level, low) -> IRQ 9 >cx88[0]/2: found at 0000:00:10.2, rev: 5, irq: 9, latency: 64, mmio: 0xfb000000 >cx8802_probe() allocating 1 frontend(s) >cx88/2: cx2388x dvb driver version 0.0.6 loaded >cx88/2: registering cx8802 driver, type: dvb access: shared >cx88[0]/2: subsystem: 0070:9202, board: Hauppauge Nova-S-Plus DVB-S [card=37] >cx88[0]/2: cx2388x based DVB/ATSC card >BUG: unable to handle kernel NULL pointer dereference at 00000000 >IP: [<e084d4ef>] :i2c_core:i2c_transfer+0x1f/0x80 >*pde = 00000000 >Modules linked in: cx88_dvb(+) cx8802 cx88xx ir_common i2c_algo_bit tveeprom videobuf_dvb btcx_risc >mga drm ipv6 fscpos eeprom nfsd exportfs stv0299 b2c2_flexcop_pci b2c2_flexcop cx24123 s5h1420 ves1x93 >dvb_ttpci dvb_core saa7146_vv saa7146 videobuf_dma_sg videobuf_core videodev v4l1_compat ttpci_eeprom >lirc_serial lirc_dev usbhid rtc uhci_hcd 8139too i2c_piix4 i2c_core usbcore evdev >Pid: 4249, comm: modprobe Not tainted (2.6.27-gentoo #3) >EIP: 0060:[<e084d4ef>] EFLAGS: 00010296 CPU: 0 >EIP is at i2c_transfer+0x1f/0x80 [i2c_core] >EAX: 00000000 EBX: ffffffa1 ECX: 00000002 EDX: d6c71e3c >ESI: d80cd050 EDI: d8093c00 EBP: d6c71e20 ESP: d6c71e0c >DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 >---[ end trace b32d87d0f0db1832 ]--- > >I added a check for i2c registration success before attaching frontends. > >Signed-off-by: Matthias Schwarzott <zzam@xxxxxxxxxx> > >Index: v4l-dvb/linux/drivers/media/video/cx88/cx88-dvb.c >=================================================================== >--- v4l-dvb.orig/linux/drivers/media/video/cx88/cx88-dvb.c >+++ v4l-dvb/linux/drivers/media/video/cx88/cx88-dvb.c >@@ -605,6 +605,11 @@ static int dvb_register(struct cx8802_de > struct videobuf_dvb_frontend *fe0, *fe1 = NULL; > int mfe_shared = 0; /* bus not shared by default */ > >+ if (0 != core->i2c_rc) { >+ printk(KERN_ERR "%s/2: no i2c-bus available, cannot attach dvb drivers\n", core->name); >+ goto frontend_detach; >+ } >+ > /* Get the first frontend */ > fe0 = videobuf_dvb_get_frontend(&dev->frontends, 1); > if (!fe0) > >--Boundary-00=_seaAJIF74ESp9Id >Content-Type: text/plain; charset="us-ascii" >MIME-Version: 1.0 >Content-Transfer-Encoding: 7bit >Content-Disposition: inline > >_______________________________________________ >linux-dvb mailing list >linux-dvb@xxxxxxxxxxx >http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb >--Boundary-00=_seaAJIF74ESp9Id-- > > -- // / {:)==={ Darron Broad <darron@xxxxxxxx> \\ \ _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
