Hi Ian, I am afraid I have more problems with running Comedi on rt-patched kernel than only that. I am still trying to figure out the specific reason - hopefully it is my fault and I scrued up my own code, but so far it seems pcie215 support doesn't work at least in the same way on rt-patched kernel as it was on non-rt. I will dig it a little bit harder, likely coming with another bug reports shoud they be observed. Do you know about other experience other people may have using Comedi for pcie215 on rt-patched kernels, specifically 4.4.70? Has Comedi been tested on rt kernels by yourself? cheers, Piotr On Mon, Jul 17, 2017 at 05:02:45PM +0100, Ian Abbott wrote: > On 17/07/17 15:48, Piotr Gregor wrote: > >Calling blocking operations from wrong context. > >Kernel: > > > >Linux piotrpc 4.4.70-rt83 #1 SMP PREEMPT RT Thu Jul 13 08:42:02 BST 2017 x86_64 GNU/Linux > > > >[ 80.542018] NOHZ: local_softirq_pending 80 > >[ 125.175471] ------------[ cut here ]------------ > >[ 125.175491] WARNING: CPU: 0 PID: 1497 at kernel/sched/core.c:7833 __might_sleep+0x9f/0xb0() > >[ 125.175728] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffffc0575741>] comedi_read+0x1a1/0x610 [comedi] > >[ 125.175735] Modules linked in: cpufreq_conservative cpufreq_powersave cpufreq_userspace cfg80211 nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc nls_ascii nls_cp437 vfat fat snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic intel_rapl joydev intel_powerclamp coretemp kvm drbg efi_pstore ansi_cprng irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd i915 serio_raw pcspkr efivars snd_hda_intel amplc_dio200_pci(C) amplc_dio200_common(C) snd_hda_codec iTCO_wdt comedi_8254(C) comedi_pci(C) iTCO_vendor_support comedi(C) snd_hda_core snd_hwdep snd_pcm drm_kms_helper snd_timer drm snd mei_me soundcore mei i2c_algo_bit shpchp eeepc_wmi asus_wmi sparse_keymap mxm_wmi battery hci_uart btbcm btqca btintel > >[ 125.175824] bluetooth > >[ 125.175825] wmi > >[ 125.175826] rfkill > >[ 125.175827] video > >[ 125.175828] intel_lpss_acpi > >[ 125.175830] intel_lpss > >[ 125.175831] evdev > >[ 125.175832] mfd_core > >[ 125.175833] acpi_als > >[ 125.175834] acpi_pad > >[ 125.175835] kfifo_buf > >[ 125.175836] button > >[ 125.175838] industrialio > >[ 125.175839] fuse > >[ 125.175840] parport_pc > >[ 125.175841] ppdev > >[ 125.175842] lp > >[ 125.175843] parport > >[ 125.175844] autofs4 > >[ 125.175845] ext4 > >[ 125.175846] crc16 > >[ 125.175847] mbcache > >[ 125.175848] jbd2 > >[ 125.175849] hid_generic > >[ 125.175851] usbhid > >[ 125.175852] sg > >[ 125.175853] sr_mod > >[ 125.175854] cdrom > >[ 125.175855] sd_mod > >[ 125.175856] crc32c_intel > >[ 125.175857] ahci > >[ 125.175858] libahci > >[ 125.175859] psmouse > >[ 125.175860] xhci_pci > >[ 125.175861] libata > >[ 125.175862] r8169 > >[ 125.175864] i2c_i801 > >[ 125.175865] mii > >[ 125.175866] xhci_hcd > >[ 125.175867] tg3 > >[ 125.175868] ptp > >[ 125.175869] scsi_mod > >[ 125.175870] usbcore > >[ 125.175871] pps_core > >[ 125.175872] libphy > >[ 125.175873] usb_common > >[ 125.175874] fan > >[ 125.175875] thermal > >[ 125.175876] i2c_hid > >[ 125.175877] hid > >[ 125.175878] fjes > > > >[ 125.175926] CPU: 0 PID: 1497 Comm: txrx Tainted: G WC 4.4.70-rt83 #1 > >[ 125.175928] Hardware name: NOVATECH LTD PC-XB04472/H110M-C, BIOS 3019 01/06/2017 > >[ 125.175935] 0000000000000000 ffff8802205b3cb0 ffffffff81387160 ffff8802205b3cf8 > >[ 125.175940] 0000000000000009 ffff8802205b3ce8 ffffffff81089766 ffffffffc057ca60 > >[ 125.175944] 00000000000002dc 0000000000000000 0000000000000001 0000000000000001 > >[ 125.175945] Call Trace: > >[ 125.175955] [<ffffffff81387160>] dump_stack+0x85/0xc5 > >[ 125.175963] [<ffffffff81089766>] warn_slowpath_common+0x86/0xe0 > >[ 125.175971] [<ffffffff8108980c>] warn_slowpath_fmt+0x4c/0x50 > >[ 125.175980] [<ffffffff81185577>] ? trace_preempt_on+0x1a7/0x2b0 > >[ 125.175985] [<ffffffff8168ca95>] ? schedule+0x55/0xe0 > >[ 125.175994] [<ffffffffc0575741>] ? comedi_read+0x1a1/0x610 [comedi] > >[ 125.176001] [<ffffffffc0575741>] ? comedi_read+0x1a1/0x610 [comedi] > >[ 125.176005] [<ffffffff810b6d0f>] __might_sleep+0x9f/0xb0 > >[ 125.176012] [<ffffffff811f54cb>] __might_fault+0x3b/0xb0 > >[ 125.176020] [<ffffffffc057597f>] comedi_read+0x3df/0x610 [comedi] > >[ 125.176034] [<ffffffff810bebf0>] ? wake_up_process+0x20/0x20 > >[ 125.176044] [<ffffffff812406d8>] __vfs_read+0x28/0xe0 > >[ 125.176053] [<ffffffff812f1f06>] ? security_file_permission+0xa6/0xc0 > >[ 125.176060] [<ffffffff81240c53>] ? rw_verify_area+0x53/0xf0 > >[ 125.176066] [<ffffffff81240d79>] vfs_read+0x89/0x130 > >[ 125.176074] [<ffffffff81241b79>] SyS_read+0x49/0xb0 > >[ 125.176084] [<ffffffff81691876>] entry_SYSCALL_64_fastpath+0x16/0x7a > >[ 125.176095] ---[ end trace 0000000000000003 ]--- > > > > > >cheers, > >Piotr > > Thanks for the bug report. I think comedi_read() in > "drivers/staging/comedi/comedi_fops.c" needs a call to > set_current_state(TASK_RUNNING) just before the call to copy_to_user(...). > > Similarly, comedi_write() needs a call to set_current_task(TASK_RUNNING) > just before the call to copy_from_user(...), and another call to > set_current_task(TASK_RUNNING) before the call to mutex_lock(). > > I'll work on a patch. > > -- > -=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=- > -=( Web: http://www.mev.co.uk/ )=- _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
