Package: alsa-source Version: 1.0.21+dfsg-2 Severity: important *** Please type your report below this line ***
When I try to use the "HR timer" as a MIDI sequencer timer in the Rosegarden (http://www.rosegardenmusic.com) application, the system freezes. Another people also reported similar problems with other sequencer - OpenOctave ( https://linuxmusicians.com/viewtopic.php?f=27&p=8917 ) I have tested the problem on two SMP machines with diffrent kernels (2.6.30, 2.6.31.6, 2.6.32). The problem seems to be associated with the "snd-hrtimer" module. I've tried to run the application vie remote X session, while having the text console active. Before the machine froze, the following messages have been displayed in the console: System 1 (Intel(R) Pentium(R) 4 CPU 2.80GHz HT) hrtimer: interrupt too slow, forcing clock min delta to 3568 ns System 2 (Intel(R) Core(TM)2 CPU T5500 @ 1.66GHz) hrtimer: interrupt too slow, forcing clock min delta to 11103 ns CE: hpet increasing min_delta_ns to 15000 nsec CE: hpet increasing min_delta_ns to 22500 nsec CE: hpet increasing min_delta_ns to 33750 nsec Analyzing the problem, I had an idea, that maybe the snd-hrtimer should be rewritten to call the callback via tasklet (I attach my patch only as an ilustration, my code doesn't work either), however then I got the message "BUG: scheduling while atomic" or something like this from the snd_hrtimer_stop function called from _snd_timer_stop. Therefore I've tried to investigate the snd_hrtimer_stop more thoroughly. Looking further into the code, I have found, that snd_hrtimer_stop may be called from the callback routine (e.g.: http://lxr.linux.no/linux+v2.6.32/sound/core/timer.c#L709 or http://lxr.linux.no/linux+v2.6.32/sound/core/timer.c#L719 ) It seems to me, that calling hrtimer_cancel (in the original code), which waits for the handler to finish, from that handler may lock the machine... (snd_hrtimer_callback calls the snd_timer_interrupt: http://lxr.linux.no/linux+v2.6.32/sound/core/hrtimer.c#L47 which in turn calls snd_hrtimer_stop (as above) which calls hrtimer_cancel). Unfortunately currently I have no idea how to fix this problem. Maybe snd_hrtimer_stop shouldn't try to cancel the timer, instead setting a flag causing callback to return immediately without rearming of the timer? Wojtek Zabolotny [email protected] PS. The above bug has been also reported to LKML -- Package-specific info: --- Begin additional package status --- Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Description +++-==============-==============-============================================ ii alsa-base 1.0.21+dfsg-2 ALSA driver configuration files ii libasound2 1.0.21a-1 shared library for ALSA applications --- End additional package status --- --- Begin /proc/asound/version --- Advanced Linux Sound Architecture Driver Version 1.0.20. --- End /proc/asound/version --- --- Begin /proc/asound/cards --- 0 [ICH5 ]: ICH4 - Intel ICH5 Intel ICH5 with AD1985 at irq 17 1 [UGM96 ]: USB-Audio - UGM96 EGOSYS, Inc. UGM96 at usb-0000:00:1d.2-2, full speed 2 [Xboard49 ]: USB-Audio - E-MU Xboard49 E-MU Systems, Inc. E-MU Xboard49 at usb-0000:00:1d.0-1.1, full speed --- End /proc/asound/cards --- --- Begin /dev/snd/ listing --- total 0 drwxr-xr-x 2 root root 80 Dec 9 16:55 by-id drwxr-xr-x 2 root root 100 Dec 9 16:55 by-path crw-rw---- 1 root audio 116, 10 Dec 9 16:55 controlC0 crw-rw---- 1 root audio 116, 13 Dec 9 16:55 controlC1 crw-rw---- 1 root audio 116, 15 Dec 9 16:55 controlC2 crw-rw---- 1 root audio 116, 14 Dec 9 16:55 midiC2D0 crw-rw---- 1 root audio 116, 9 Dec 9 16:58 pcmC0D0c crw-rw---- 1 root audio 116, 8 Dec 9 16:58 pcmC0D0p crw-rw---- 1 root audio 116, 7 Dec 9 16:55 pcmC0D1c crw-rw---- 1 root audio 116, 6 Dec 9 16:55 pcmC0D2c crw-rw---- 1 root audio 116, 5 Dec 9 16:55 pcmC0D3c crw-rw---- 1 root audio 116, 4 Dec 9 16:58 pcmC0D4p crw-rw---- 1 root audio 116, 12 Dec 9 16:58 pcmC1D0c crw-rw---- 1 root audio 116, 11 Dec 9 16:58 pcmC1D0p crw-rw---- 1 root audio 116, 3 Dec 9 16:55 seq crw-rw---- 1 root audio 116, 2 Dec 9 16:55 timer --- End /dev/snd/ listing --- -- System Information: Debian Release: squeeze/sid APT prefers testing APT policy: (990, 'testing'), (100, 'stable'), (50, 'unstable') Architecture: i386 (i686) Kernel: Linux 2.6.31.6.media (SMP w/2 CPU cores; PREEMPT) Locale: LANG=pl_PL.UTF-8, LC_CTYPE=pl_PL.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/bash Versions of packages alsa-source depends on: ii bzip2 1.0.5-3 high-quality block-sorting file co ii debconf [debconf-2.0] 1.5.28 Debian configuration management sy ii debconf-utils 1.5.28 debconf utilities ii debhelper 7.4.3 helper programs for debian/rules ii dpkg-dev 1.15.5.3 Debian package development tools ii gcc [c-compiler] 4:4.3.4-1 The GNU C compiler ii gcc-4.1 [c-compiler] 4.1.2-27 The GNU C compiler ii gcc-4.2 [c-compiler] 4.2.4-6 The GNU C compiler ii gcc-4.3 [c-compiler] 4.3.4-6 The GNU C compiler ii make 3.81-7 An utility for Directing compilati Versions of packages alsa-source recommends: ii fakeroot 1.14.4-1 Gives a fake root environment ii kernel-package 12.031 A utility for building Linux kerne ii linux-headers-2.6.31 [linux- 10:wzab.1.0 Header files related to Linux kern ii linux-headers-2.6.31.4 [linu 10:wzab.1.0 Header files related to Linux kern ii linux-headers-2.6.31.6 [linu 10:wzab.1.0 Header files related to Linux kern ii linux-headers-2.6.31.6.media 10:wzab.1.0 Header files related to Linux kern ii module-assistant 0.11.1 tool to make module package creati alsa-source suggests no packages. Versions of packages alsa-base depends on: ii linux-sound-base 1.0.21+dfsg-2 base package for ALSA and OSS soun ii lsof 4.81.dfsg.1-1 List open files ii module-init-tools 3.11-1 tools for managing Linux kernel mo ii udev 146-5 /dev/ and hotplug management daemo Versions of packages libasound2 depends on: ii libc6 2.10.2-2 GNU C Library: Shared libraries -- debconf information: alsa-source/cards_to_be_built: all alsa-source/debug: false alsa-source/cards: alsa-source/has_pnp: true alsa-source/cards_with_descriptions: -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]
