Em Sun, 22 Dec 2013 00:27:21 +0200 Antti Palosaari <crope@xxxxxx> escreveu: > I ran also this kind of bug. Device was PCTV 290e, which has that video > unused. I have no any analog em28xx webcam to test if that happens here too. > > Fortunately I found one video device which does not crash nor dump debug > bug warnings. It is some old gspca webcam. Have to look example how > those videobuf callbacks are implemented there.. > > regards > Antti > > > [crope@localhost linux]$ cat /dev/video0 > cat: /dev/video0: Invalid argument > [crope@localhost linux]$ cat /dev/video0 > cat: /dev/video0: Device or resource busy > [crope@localhost linux]$ > > > joulu 22 00:08:24 localhost.localdomain kernel: em28174 #0: no endpoint > for analog mode and transfer type 0 It seems that there's something bad on em28174 registration: it should not be creating a v4l2 device, if the device is DVB only. The thing is that, when this driver was created, all devices were either analog only or hybrid. Only very recently, pure DVB devices got added. It shouldn't be that hard to split em28xx_init_dev() into a few routines that would only register v4l2 if the device has analog support. Again, this changeset: https://patchwork.linuxtv.org/patch/17967/ Seems to be part of such solution, as it already splits the v4l2 register logic into a separate function. > joulu 22 00:08:31 localhost.localdomain kernel: ------------[ cut here > ]------------ > joulu 22 00:08:31 localhost.localdomain kernel: WARNING: CPU: 3 PID: > 6892 at lib/list_debug.c:33 __list_add+0xac/0xc0() > joulu 22 00:08:31 localhost.localdomain kernel: list_add corruption. > prev->next should be next (ffff88030b686498), but was (null). > (prev=ffff88030c6c1748). > joulu 22 00:08:31 localhost.localdomain kernel: Modules linked in: > rc_pinnacle_pctv_hd(O) em28xx_rc(O) tda18271(O) cxd2820r(O) > em28xx_dvb(O) r820t(O) mn88472(O) rtl2832_sd...b_usb_af901 > joulu 22 00:08:31 localhost.localdomain kernel: CPU: 3 PID: 6892 Comm: > cat Tainted: G C O 3.13.0-rc1+ #77 > joulu 22 00:08:31 localhost.localdomain kernel: Hardware name: System > manufacturer System Product Name/M5A78L-M/USB3, BIOS 1503 11/14/2012 > joulu 22 00:08:31 localhost.localdomain kernel: 0000000000000009 > ffff8803052afcb8 ffffffff816b8da9 ffff8803052afd00 > joulu 22 00:08:31 localhost.localdomain kernel: ffff8803052afcf0 > ffffffff8106bcfd ffff88030c6c5348 ffff88030b686498 > joulu 22 00:08:31 localhost.localdomain kernel: ffff88030c6c1748 > 0000000000000292 0000000000000001 ffff8803052afd50 > joulu 22 00:08:31 localhost.localdomain kernel: Call Trace: > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffff816b8da9>] > dump_stack+0x4d/0x66 > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffff8106bcfd>] > warn_slowpath_common+0x7d/0xa0 > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffff8106bd6c>] > warn_slowpath_fmt+0x4c/0x50 > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffff8134c2dc>] > __list_add+0xac/0xc0 > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffffa0273a7b>] > buffer_queue+0x7b/0xb0 [em28xx] > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffffa025a2d4>] > __enqueue_in_driver+0x74/0x80 [videobuf2_core] > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffffa025c568>] > vb2_streamon+0xa8/0x190 [videobuf2_core] > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffffa025dd12>] > __vb2_init_fileio+0x332/0x3a0 [videobuf2_core] > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffffa025e733>] > __vb2_perform_fileio+0x483/0x620 [videobuf2_core] > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffffa025eae4>] > vb2_fop_read+0xc4/0x5e0 [videobuf2_core] > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffffa022da55>] > v4l2_read+0x65/0xb0 [videodev] > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffff811cc498>] > vfs_read+0x98/0x170 > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffff811ccfdc>] > SyS_read+0x4c/0xa0 > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffff8110affc>] ? > __audit_syscall_entry+0x9c/0xf0 > joulu 22 00:08:31 localhost.localdomain kernel: [<ffffffff816ca729>] > system_call_fastpath+0x16/0x1b > joulu 22 00:08:31 localhost.localdomain kernel: ---[ end trace > dcb247cebbcc2a82 ]--- > > > -- Cheers, Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
