The patch number 9357 was added via Mauro Carvalho Chehab <[EMAIL PROTECTED]>
to http://linuxtv.org/hg/v4l-dvb master development tree.
Kernel patches in this development tree may be modified to be backward
compatible with older kernels. Compatibility modifications will be
removed before inclusion into the mainstream Kernel
If anyone has any objections, please let us know by sending a message to:
[EMAIL PROTECTED]
------
From: Matthias Schwarzott <[EMAIL PROTECTED]>
cx88-dvb: Fix Oops in case i2c bus failed to register
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
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
Signed-off-by: Mauro Carvalho Chehab <[EMAIL PROTECTED]>
---
linux/drivers/media/video/cx88/cx88-dvb.c | 5 +++++
1 file changed, 5 insertions(+)
diff -r 33626df3ba2c -r e414eb18bc7b linux/drivers/media/video/cx88/cx88-dvb.c
--- a/linux/drivers/media/video/cx88/cx88-dvb.c Mon Oct 20 13:57:02 2008 -0700
+++ b/linux/drivers/media/video/cx88/cx88-dvb.c Fri Oct 24 13:47:07 2008 +0000
@@ -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)
---
Patch is available at:
http://linuxtv.org/hg/v4l-dvb/rev/e414eb18bc7bfe2a1bc7ff50af9bf28363314af5
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