{"action":"created","issue":{"url":"https://api.github.com/repos/raspberrypi/firmware/issues/192","labels_url":"https://api.github.com/repos/raspberrypi/firmware/issues/192/labels{/name}","comments_url":"https://api.github.com/repos/raspberrypi/firmware/issues/192/comments","events_url":"https://api.github.com/repos/raspberrypi/firmware/issues/192/events","html_url":"https://github.com/raspberrypi/firmware/issues/192","id":16178852,"number":192,"title":"kworker task blocked - reading temperature?","user":{"login":"MilhouseVH","id":805038,"avatar_url":"https://avatars.githubusercontent.com/u/805038?v=3","gravatar_id":"","url":"https://api.github.com/users/MilhouseVH","html_url":"https://github.com/MilhouseVH","followers_url":"https://api.github.com/users/MilhouseVH/followers","following_url":"https://api.github.com/users/MilhouseVH/following{/other_user}","gists_url":"https://api.github.com/users/MilhouseVH/gists{/gist_id}","starred_url":"https://api.github.com/users/MilhouseVH/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/MilhouseVH/subscriptions","organizations_url":"https://api.github.com/users/MilhouseVH/orgs","repos_url":"https://api.github.com/users/MilhouseVH/repos","events_url":"https://api.github.com/users/MilhouseVH/events{/privacy}","received_events_url":"https://api.github.com/users/MilhouseVH/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":49,"created_at":"2013-06-29T19:15:05Z","updated_at":"2015-06-21T11:38:01Z","closed_at":null,"body":"I left a headless 512MB Pi (16MB GPU, wired network on eth0) running with the latest firmware for several days, and it has just hung with the following backtrace:\r\n\r\n```\r\nJun 29 19:42:57 raspberrypi upsmon[2208]: Poll UPS [ups@192.168.0.2] failed - Server disconnected\r\nJun 29 19:42:57 raspberrypi upsmon[2208]: Communications with UPS ups@192.168.0.2 lost\r\nJun 29 19:44:06 raspberrypi upsmon[2208]: UPS [ups@192.168.0.2]: connect failed: Connection failure: Connection timed out\r\nJun 29 19:45:14 raspberrypi upsmon[2208]: UPS [ups@192.168.0.2]: connect failed: Connection failure: Connection timed out\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939467] INFO: task kworker/0:2:5386 blocked for more than 120 seconds.\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939483] \"echo 0 > /proc/sys/kernel/hung_task_timeout_secs\" disables this message.\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939491] kworker/0:2     D c0398690     0  5386      2 0x00000000\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939545] [<c0398690>] (__schedule+0x2c4/0x5b0) from [<c03973d0>] (schedule_timeout+0x158/0x1e0)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939703] [<c03973d0>] (schedule_timeout+0x158/0x1e0) from [<c03980c0>] (__down+0x88/0xc0)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939733] [<c03980c0>] (__down+0x88/0xc0) from [<c00400c0>] (down+0x60/0x64)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939764] [<c00400c0>] (down+0x60/0x64) from [<c001a678>] (bcm_mailbox_read+0x60/0x98)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939784] [<c001a678>] (bcm_mailbox_read+0x60/0x98) from [<c001a774>] (bcm_mailbox_property+0xc4/0x15c)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939811] [<c001a774>] (bcm_mailbox_property+0xc4/0x15c) from [<c02b1538>] (bcm2835_get_temp_or_max.isra.0+0x50/0xb8)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939831] [<c02b1538>] (bcm2835_get_temp_or_max.isra.0+0x50/0xb8) from [<c02b0520>] (thermal_zone_device_update+0x2c/0x240)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939850] [<c02b0520>] (thermal_zone_device_update+0x2c/0x240) from [<c0035010>] (process_one_work+0x150/0x40c)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939866] [<c0035010>] (process_one_work+0x150/0x40c) from [<c00355f0>] (worker_thread+0x150/0x498)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939887] [<c00355f0>] (worker_thread+0x150/0x498) from [<c003a7b4>] (kthread+0x88/0x94)\r\nJun 29 19:45:39 raspberrypi kernel: [745389.939910] [<c003a7b4>] (kthread+0x88/0x94) from [<c000e9fc>] (kernel_thread_exit+0x0/0x8)\r\nJun 29 19:46:22 raspberrypi upsmon[2208]: UPS [ups@192.168.0.2]: connect failed: Connection failure: Connection timed out\r\nJun 29 19:17:33 raspberrypi kernel: imklog 5.8.11, log source = /proc/kmsg started.\r\n```\r\n\r\nCurrent firmware:\r\n```\r\npi@raspberrypi /var/log $ uname -a && vcgencmd version\r\nLinux raspberrypi 3.6.11+ #474 PREEMPT Thu Jun 13 17:14:42 BST 2013 armv6l GNU/Linux\r\nJun 17 2013 20:43:10\r\nCopyright (c) 2012 Broadcom\r\nversion d380dde43fe729f043befb5cf775f99e54586cde (clean) (release)\r\n```\r\n\r\nAs with issue #132, I'm polling the temperature every 10 seconds, and the backtrace references bcm2835_get_temp so maybe there's still a problem there? However this doesn't appear to be a regression of #132 - running multiple concurrent processes reading the temperature do not provoke a backtrace.\r\n\r\nA few minutes prior to this latest backtrace, the NUT client began reporting a communication problem with the network UPS which may be related (there is nothing wrong with the UPS, so it looks like an eth0 communication problem on the Pi side).\r\n\r\nThe Pi didn't actually crash, but it did lose all network access so had to be power cycled."},"comment":{"url":"https://api.github.com/repos/raspberrypi/firmware/issues/comments/113886890","html_url":"https://github.com/raspberrypi/firmware/issues/192#issuecomment-113886890","issue_url":"https://api.github.com/repos/raspberrypi/firmware/issues/192","id":113886890,"user":{"login":"popcornmix","id":1053730,"avatar_url":"https://avatars.githubusercontent.com/u/1053730?v=3","gravatar_id":"","url":"https://api.github.com/users/popcornmix","html_url":"https://github.com/popcornmix","followers_url":"https://api.github.com/users/popcornmix/followers","following_url":"https://api.github.com/users/popcornmix/following{/other_user}","gists_url":"https://api.github.com/users/popcornmix/gists{/gist_id}","starred_url":"https://api.github.com/users/popcornmix/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/popcornmix/subscriptions","organizations_url":"https://api.github.com/users/popcornmix/orgs","repos_url":"https://api.github.com/users/popcornmix/repos","events_url":"https://api.github.com/users/popcornmix/events{/privacy}","received_events_url":"https://api.github.com/users/popcornmix/received_events","type":"User","site_admin":false},"created_at":"2015-06-21T11:38:01Z","updated_at":"2015-06-21T11:38:01Z","body":"I've left:\r\n``while :; do cat /sys/class/thermal/thermal_zone0/temp; done``\r\nrunning over the last couple of nights with gpu debugger attached and it's still running without errors in the morning."}}