Re: [v4l-dvb-maintainer] [patch, -git] drivers/media build fix for modular builds

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 30 Apr 2008 10:39:31 -0400 "Michael Krufky" <mkrufky@linuxtv.org> wrote:

> On Wed, Apr 30, 2008 at 9:03 AM, Mike Galbraith <efault@gmx.de> wrote:
> >
> >  On Wed, 2008-04-30 at 04:40 -0700, Andrew Morton wrote:
> >  > On Wed, 30 Apr 2008 11:20:31 +0200 Mike Galbraith <efault@gmx.de> wrote:
> >  >
> >  > > [   16.299803] kernel BUG at kernel/module.c:784!
> >  > > [   16.307170] invalid opcode: 0000 [1] SMP
> >  > > [   16.314110] CPU 3
> >  > > [   16.318911] Modules linked in: tuner(+) snd_hda_intel(+) saa7134(+) compat_ioctl32 firewire_ohci videodev snd_pcm firewire_core v4l1_compat v4l2_common snd_timer videobuf_dma_sg videobuf_core crc_itu_t snd_page_alloc snd_hwdep ir_kbd_i2c ohci1394 snd ir_common usb_storage rtc_cmos ieee1394 tveeprom rtc_core i2c_i801 button sr_mod intel_agp serio_raw e1000e iTCO_wdt i2c_core iTCO_vendor_support rtc_lib cdrom sg soundcore usbhid hid ff_memless ehci_hcd uhci_hcd sd_mod usbcore edd ext3 mbcache jbd fan ahci libata scsi_mod dock thermal processor
> >  > > [   16.386303] Pid: 2239, comm: modprobe Not tainted 2.6.26-smp #1
> >  > > [   16.395339] RIP: 0010:[<ffffffff80254714>]  [<ffffffff80254714>] __symbol_put+0x22/0x31
> >  >
> >  > Does this make it feel better?
> >
> >  Well, it doesn't go BUG() any more, but it now goes oops.
> >
> >  [   13.443404] saa7133[0]: i2c eeprom 00: be 16 0d 00 54 20 1c 00 43 43 a9 1c 55 d2 b2 92
> >  [   13.456281] saa7133[0]: i2c eeprom 10: 00 ff 86 0f ff 20 ff 00 01 50 32 79 01 3c ca 50
> >  [   13.469575] saa7133[0]: i2c eeprom 20: 01 40 01 02 02 03 01 00 06 ff 00 29 02 51 96 2b
> >  [   13.483794] saa7133[0]: i2c eeprom 30: a7 58 7a 1f 03 8e 84 5e da 7a 04 b3 05 87 b2 3c
> >  [   13.498518] saa7133[0]: i2c eeprom 40: ff 28 00 c0 96 10 03 00 c0 1c fd 79 44 9f c2 8f
> >  [   13.507664] saa7133[0]: i2c eeprom 50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507670] saa7133[0]: i2c eeprom 60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507676] saa7133[0]: i2c eeprom 70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507680] saa7133[0]: i2c eeprom 80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507684] saa7133[0]: i2c eeprom 90: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507688] saa7133[0]: i2c eeprom a0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507692] saa7133[0]: i2c eeprom b0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507696] saa7133[0]: i2c eeprom c0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507700] saa7133[0]: i2c eeprom d0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507703] saa7133[0]: i2c eeprom e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.507707] saa7133[0]: i2c eeprom f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
> >  [   13.666587] TUNER: Unable to find symbol tda829x_probe()
> >  [   13.674638] tuner' 1-004b: chip found @ 0x96 (saa7133[0])
> >  [   13.691175] DVB: Unable to find symbol tda9887_attach()
> >  [   13.698968] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
> >  [   13.709509] IP: [<ffffffff80302934>] strlcpy+0x11/0x36
> >  [   13.711135] PGD be167067 PUD be140067 PMD 0
> >  [   13.711137] Oops: 0000 [1] SMP
> >  [   13.711139] CPU 2
> >  [   13.711140] Modules linked in: tuner(+) snd_hda_intel(+) saa7134(+) compat_ioctl32 snd_pcm videodev firewire_ohci v4l1_compat firewire_core v4l2_common snd_timer videobuf_dma_sg videobuf_core crc_itu_t snd_page_alloc snd_hwdep ir_kbd_i2c rtc_cmos snd rtc_core ohci1394 ir_common usb_storage usbhid tveeprom ieee1394 sr_mod e1000e i2c_i801 rtc_lib cdrom i2c_core hid iTCO_wdt button intel_agp serio_raw ff_memless soundcore iTCO_vendor_support sg ehci_hcd uhci_hcd sd_mod usbcore edd ext3 mbcache jbd fan ahci libata scsi_mod dock thermal processor
> >  [   13.711158] Pid: 2175, comm: modprobe Not tainted 2.6.26-smp #3
> >  [   13.711160] RIP: 0010:[<ffffffff80302934>]  [<ffffffff80302934>] strlcpy+0x11/0x36
> >  [   13.711163] RSP: 0018:ffff8100bcc45b68  EFLAGS: 00010286
> >  [   13.711164] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffffffffffff
> >  [   13.711165] RDX: 0000000000000014 RSI: 0000000000000000 RDI: 0000000000000000
> >  [   13.711167] RBP: ffff8100bcc45b68 R08: ffff8100bf0b7404 R09: 0000000000000000
> >  [   13.711169] R10: ffff8100bcc45908 R11: ffff81003784ab70 R12: ffff8100bf0b6400
> >  [   13.711170] R13: ffff8100bf0b7400 R14: 000000000000004a R15: 000000000000000e
> >  [   13.711172] FS:  00007fcb8bad66f0(0000) GS:ffff8100bf806780(0000) knlGS:0000000000000000
> >  [   13.711174] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> >  [   13.711175] CR2: 0000000000000000 CR3: 00000000be142000 CR4: 00000000000006e0
> >  [   13.711177] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> >  [   13.711178] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> >  [   13.711180] Process modprobe (pid: 2175, threadinfo ffff8100bcc44000, task ffff8100bd112c40)
> >  [   13.711181] Stack:  ffff8100bcc45c08 ffffffffa02d43a3 0000000000000096 ffff8100bd486490
> >  [   13.711185]  0000000000000000 ffffffffa02d681c ffff8100bcc45bd8 ffffffff80253b08
> >  [   13.711187]  ffff8100bcc45bf8 ffff8100bf0b7400 ffff8100bf0b6400 ffffffffa02d8e80
> >  [   13.711190] Call Trace:
> >  [   13.711196]  [<ffffffffa02d43a3>] :tuner:set_type+0x682/0x9ed

I worry about this case:

		case 0x42:
		case 0x43:
		case 0x4a:
		case 0x4b:
			/* If chip is not tda8290, don't register.
			   since it can be tda9887*/
			if (tuner_symbol_probe(tda829x_probe, t->i2c->adapter,
					       t->i2c->addr) == 0) {
				tuner_dbg("tda829x detected\n");
			} else {
				/* Default is being tda9887 */
				t->type = TUNER_TDA9887;
				t->mode_mask = T_RADIO | T_ANALOG_TV |
					       T_DIGITAL_TV;
				t->mode = T_STANDBY;
				goto register_client;
			}
			break;

did we really want to go ahead and perform registration if
tuner_symbol_probe() failed?