Hi all, I wonder if Devin/Mauro could help me with something as I've run into a problem developing a driver for the PCTV 290e?
First plug of the device works fine, em28xx and em28xx_dvb are loaded. However, if I disconnect and then re-plug the device, the em28xx_dvb module will hang in dvb_init() where it performs mutex_lock(&dev->lock); It looks like the code to handle udev locking runs into a problem if the em28xx_dvb is already loaded. I'm referring to this: https://patchwork.kernel.org/patch/91160/ I don't have any other em28xx DVB devices to test against at the moment. I have modified dvb_init to give up if it doesn't get a lock straight away. This is not a valid fix, but it means I can run rmmod instead of rebooting. Below is a copy of khubd's complaint about the hangup. I pulled from media_tree.git. Perhaps this is already fixed in another branch? Thanks. [31498.792677] INFO: task khubd:28 blocked for more than 120 seconds. [31498.792682] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [31498.792685] khubd D ffff880232d59a58 0 28 2 0x00000000 [31498.792689] ffff880232d4d6b0 0000000000000046 ffff880232d4d600 ffffffff81036bb9 [31498.792692] 0000000000013a80 ffff880232d596c0 ffff880232d59a58 ffff880232d4dfd8 [31498.792695] ffff880232d59a60 0000000000013a80 ffff880232d4c010 0000000000013a80 [31498.792699] Call Trace: [31498.792708] [<ffffffff81036bb9>] ? default_spin_lock_flags+0x9/0x10 [31498.792714] [<ffffffff81598817>] __mutex_lock_slowpath+0xf7/0x180 [31498.792717] [<ffffffff815986fb>] mutex_lock+0x2b/0x50 [31498.792722] [<ffffffffa07f43c9>] dvb_init+0x69/0xc20 [em28xx_dvb] [31498.792730] [<ffffffffa07a84c2>] em28xx_init_extension+0x42/0x70 [em28xx] [31498.792735] [<ffffffffa07a7e89>] em28xx_usb_probe+0x6a9/0xb10 [em28xx] [31498.792741] [<ffffffff814173c3>] usb_probe_interface+0xf3/0x210 [31498.792746] [<ffffffff813979f6>] driver_probe_device+0x96/0x1c0 [31498.792749] [<ffffffff81397bc0>] ? __device_attach+0x0/0x60 [31498.792751] [<ffffffff81397c13>] __device_attach+0x53/0x60 [31498.792755] [<ffffffff81396a88>] bus_for_each_drv+0x68/0x90 [31498.792757] [<ffffffff81397cdf>] device_attach+0x8f/0xb0 [31498.792760] [<ffffffff8139685d>] bus_probe_device+0x2d/0x50 [31498.792764] [<ffffffff813951c9>] device_add+0x639/0x710 [31498.792767] [<ffffffff81393a01>] ? dev_set_name+0x41/0x50 [31498.792770] [<ffffffff81415a26>] usb_set_configuration+0x606/0x6d0 [31498.792774] [<ffffffff8141f064>] generic_probe+0x44/0xa0 [31498.792777] [<ffffffff81416c10>] usb_probe_device+0x30/0x60 [31498.792779] [<ffffffff813979f6>] driver_probe_device+0x96/0x1c0 [31498.792782] [<ffffffff81397bc0>] ? __device_attach+0x0/0x60 [31498.792784] [<ffffffff81397c13>] __device_attach+0x53/0x60 [31498.792787] [<ffffffff81396a88>] bus_for_each_drv+0x68/0x90 [31498.792789] [<ffffffff81397cdf>] device_attach+0x8f/0xb0 [31498.792792] [<ffffffff8139685d>] bus_probe_device+0x2d/0x50 [31498.792795] [<ffffffff813951c9>] device_add+0x639/0x710 [31498.792797] [<ffffffff81415279>] ? usb_cache_string+0x99/0xb0 [31498.792800] [<ffffffff8140e3cb>] usb_new_device+0x9b/0x140 [31498.792803] [<ffffffff8140f428>] hub_thread+0xc18/0x11a0 [31498.792806] [<ffffffff8105afee>] ? dequeue_task_fair+0x29e/0x2b0 [31498.792811] [<ffffffff81083000>] ? autoremove_wake_function+0x0/0x40 [31498.792813] [<ffffffff8140e810>] ? hub_thread+0x0/0x11a0 [31498.792816] [<ffffffff81082ab6>] kthread+0x96/0xa0 [31498.792820] [<ffffffff8100cde4>] kernel_thread_helper+0x4/0x10 [31498.792823] [<ffffffff81082a20>] ? kthread+0x0/0xa0 [31498.792825] [<ffffffff8100cde0>] ? kernel_thread_helper+0x0/0x10 [31498.792868] INFO: task usb_id:19221 blocked for more than 120 seconds. [31498.792870] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [31498.792872] usb_id D ffff8802016b8398 0 19221 1 0x00000000 [31498.792875] ffff88018ac9fda8 0000000000000082 0000000003a65c58 0000000000000000 [31498.792878] 0000000000013a80 ffff8802016b8000 ffff8802016b8398 ffff88018ac9ffd8 [31498.792882] ffff8802016b83a0 0000000000013a80 ffff88018ac9e010 0000000000013a80 [31498.792885] Call Trace: [31498.792888] [<ffffffff81598817>] __mutex_lock_slowpath+0xf7/0x180 [31498.792891] [<ffffffff815986fb>] mutex_lock+0x2b/0x50 [31498.792895] [<ffffffff8141a51f>] show_manufacturer+0x2f/0x70 [31498.792898] [<ffffffff81393a37>] dev_attr_show+0x27/0x50 [31498.792904] [<ffffffff8110abae>] ? __get_free_pages+0xe/0x50 [31498.792910] [<ffffffff811c6e9e>] sysfs_read_file+0xce/0x1c0 [31498.792914] [<ffffffff81159995>] vfs_read+0xc5/0x190 [31498.792916] [<ffffffff81159b61>] sys_read+0x51/0x90 [31498.792922] [<ffffffff8100bfc2>] system_call_fastpath+0x16/0x1b -- Steve Kerrison MEng Hons. http://www.stevekerrison.com/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
