Hi Jurgen, On 12/27/2014 10:35 AM, Jurgen Kramer wrote: > I am seeing kernel oopses using recent media_builds on kernel 3.17: > > [ 506.969697] BUG: unable to handle kernel NULL pointer dereference at > 0000000000000058 > [ 506.969720] IP: [<ffffffffa03a233a>] vb2_thread+0x17a/0x480 > [videobuf2_core] > [ 506.969739] PGD 0 > [ 506.969746] Oops: 0002 [#1] SMP > [ 506.969754] Modules linked in: nf_conntrack_netbios_ns > nf_conntrack_broadcast cfg80211 rfkill ip6t_rpfilter ip6t_REJECT > xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter > ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 > ip6table_mangle ip6table_security ip6table_raw ip6table_filter > ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 > nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw sp2(OE) > si2157(OE) si2168(OE) i2c_mux nouveau cx25840(OE) cx23885(OE) > altera_ci(OE) tda18271(OE) altera_stapl(OE) videobuf2_dvb(OE) > videobuf2_core(OE) videobuf2_dma_sg(OE) videobuf2_memops(OE) snd_seq > snd_seq_device snd_pcm snd_timer snd video i2c_algo_bit ttm > drm_kms_helper soundcore iTCO_wdt ppdev gpio_ich iTCO_vendor_support > tveeprom(OE) cx2341x(OE) > [ 506.969871] coretemp dvb_core(OE) v4l2_common(OE) videodev(OE) > media(OE) kvm crc32c_intel raid456 async_raid6_recov async_memcpy > async_pq async_xor drm xor async_tx raid6_pq microcode serio_raw shpchp > i7core_edac edac_core i2c_i801 lpc_ich mfd_core parport_pc parport > ite_cir(OE) rc_core(OE) tpm_infineon tpm_tis tpm acpi_cpufreq nfsd > auth_rpcgss nfs_acl lockd sunrpc mxm_wmi asix usbnet r8169 mii wmi > [ 506.969970] CPU: 0 PID: 3160 Comm: vb2-cx23885[0] Tainted: G > OE 3.17.4-200.fc20.x86_64 #1 > [ 506.969982] Hardware name: To Be Filled By O.E.M. To Be Filled By > O.E.M./P55 Extreme, BIOS P2.70 08/20/2010 > [ 506.969993] task: ffff8800bc18e220 ti: ffff88020d36c000 task.ti: > ffff88020d36c000 > [ 506.970002] RIP: 0010:[<ffffffffa03a233a>] [<ffffffffa03a233a>] > vb2_thread+0x17a/0x480 [videobuf2_core] > [ 506.970021] RSP: 0018:ffff88020d36fe68 EFLAGS: 00010246 > [ 506.970663] RAX: 0000000000000000 RBX: 0000000000000000 RCX: > 000000000000000b > [ 506.971305] RDX: 0000000000000058 RSI: ffff8800bc18e220 RDI: > 0000000000000058 > [ 506.971952] RBP: ffff88020d36fec0 R08: ffff88020d36c000 R09: > 000000000000158f > [ 506.972611] R10: 00000000000030de R11: 0000000000000010 R12: > 0000000000000058 > [ 506.973275] R13: ffff8800b81814a0 R14: 0000000000000000 R15: > ffff880225c61028 > [ 506.973947] FS: 0000000000000000(0000) GS:ffff880233c00000(0000) > knlGS:0000000000000000 > [ 506.974634] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 506.975321] CR2: 0000000000000058 CR3: 0000000001c14000 CR4: > 00000000000007f0 > [ 506.976021] Stack: > [ 506.976723] ffff8800bc18e220 0000000000000070 00ffffff81c1b460 > 0000000000000000 > [ 506.977442] ffff880200000000 ffff880225c61028 ffff88020d1d8480 > ffff880225c61028 > [ 506.978165] ffffffffa03a21c0 0000000000000000 0000000000000000 > ffff88020d36ff48 > [ 506.979055] Call Trace: > [ 506.979795] [<ffffffffa03a21c0>] ? vb2_internal_qbuf+0x210/0x210 > [videobuf2_core] > [ 506.980545] [<ffffffff810b0498>] kthread+0xd8/0xf0 > [ 506.981293] [<ffffffff810b03c0>] ? kthread_create_on_node > +0x190/0x190 > [ 506.982045] [<ffffffff8172e33c>] ret_from_fork+0x7c/0xb0 > [ 506.982806] [<ffffffff810b03c0>] ? kthread_create_on_node > +0x190/0x190 > [ 506.983568] Code: 89 e7 ba 58 00 00 00 0f 85 94 01 00 00 40 f6 c7 02 > 0f 85 72 01 00 00 40 f6 c7 04 0f 85 50 01 00 00 89 d1 31 c0 c1 e9 03 f6 > c2 04 <f3> 48 ab 74 0a c7 07 00 00 00 00 48 83 c7 04 f6 c2 02 74 0a 31 > [ 506.984464] RIP [<ffffffffa03a233a>] vb2_thread+0x17a/0x480 > [videobuf2_core] > [ 506.985306] RSP <ffff88020d36fe68> > [ 506.986147] CR2: 0000000000000058 > [ 506.990986] ---[ end trace 1973fbcab83c3353 ]--- > > First I thought is was related to CAM initialization but after removing > the CAMS and doing a fresh cold start I am still seeing the oopses. > After the oops everything is still functioning. I am using 3x DVBSKY > T980C. How can I debug this further? Sorry for the delay, I was on vacation. Do you get this when you start streaming, stop streaming or during streaming? I strongly suspect a race condition that can occur when stopping streaming, but I am not aware of race conditions when starting or during streaming. Please let me know when you get this, as that will be very useful information for me. Regards, Hans -- 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
