On Tuesday 03 December 2002 13:01, Takashi Iwai wrote: > At Tue, 3 Dec 2002 04:07:52 +0100, > > Duncan Sands wrote: > > Got this with today 2.5 BK tree: > > > > Debug: sleeping function called from illegal context at > > include/asm/semaphore.h:119 Call Trace: > > [<c0113f1a>] __might_sleep+0x52/0x58 > > [<c024291a>] snd_cs46xx_iec958_put+0x36/0xf8 > > [<c0217f28>] snd_ctl_elem_write+0xe0/0x1a4 > > [<c0218360>] snd_ctl_ioctl+0x184/0x2c8 > > [<c01462e6>] sys_ioctl+0x1fa/0x244 > > [<c01088f7>] syscall_call+0x7/0xb > > ouch, we are using rwlock in the control ioctls. > > mutex is necessary for many controls, so we cannot suppress the use of > mutex in control callbacks. > but temporary unlocking looks ad-hoc, too...
If I understand right, the problem is that snd_ctl_elem_write acquires control_rwlock, which is a rw spinlock. It then calls snd_cs46xx_iec958_put which acquires chip->spos_mutex, which is a semaphore. Thus the message. Now I deduce from the fact that you don't use read_lock_irqsave that the data structure is not read from interrupt context. That means you are only protecting against other CPUs. So why not use a semaphore instead of a spinlock? All the best, Duncan. ------------------------------------------------------- This SF.net email is sponsored by: Get the new Palm Tungsten T handheld. Power & Color in a compact size! http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0002en _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
