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Marginally simplify dsp_open error handling by adding an early test to

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determine liklihood of opening device in requested directions.  Makes for
simpler error handling and change should close kern/35004.

PR: kern/35004.
This commit is contained in:
Orion Hodson 2002-08-28 15:19:30 +00:00
parent e7413bff80
commit 47d5a0f3e5
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=102525
1 changed files with 51 additions and 68 deletions
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53
sys/dev/sound/pcm/dsp.c
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@ -213,21 +213,27 @@ dsp_open(dev_t i_dev, int flags, int mode, struct thread *td)
/* lock snddev so nobody else can monkey with it */
pcm_lock(d);
if ((dsp_get_flags(i_dev) & SD_F_SIMPLEX) && (i_dev->si_drv1 || i_dev->si_drv2)) {
rdch = i_dev->si_drv1;
wrch = i_dev->si_drv2;
if ((dsp_get_flags(i_dev) & SD_F_SIMPLEX) && (rdch || wrch)) {
/* simplex device, already open, exit */
pcm_unlock(d);
splx(s);
return EBUSY;
}
/* if we get here, the open request is valid */
rdch = i_dev->si_drv1;
wrch = i_dev->si_drv2;
if (((flags & FREAD) && rdch) || ((flags & FWRITE) && wrch)) {
/* device already open in one or both directions */
pcm_unlock(d);
splx(s);
return EBUSY;
}
/* if we get here, the open request is valid */
if (flags & FREAD) {
/* open for read */
if (rdch == NULL) {
/* not already open, try to get a channel */
if (devtype == SND_DEV_DSPREC)
rdch = pcm_chnalloc(d, PCMDIR_REC, td->td_proc->p_pid, PCMCHAN(i_dev));
else
@ -239,22 +245,14 @@ dsp_open(dev_t i_dev, int flags, int mode, struct thread *td)
return EBUSY;
}
/* got a channel, already locked for us */
} else {
/* already open for read, exit */
pcm_unlock(d);
splx(s);
return EBUSY;
}
}
if (flags & FWRITE) {
/* open for write */
if (wrch == NULL) {
/* not already open, try to get a channel */
wrch = pcm_chnalloc(d, PCMDIR_PLAY, td->td_proc->p_pid, -1);
if (!wrch) {
/* no channel available */
if (rdch && (flags & FREAD)) {
if (flags & FREAD) {
/* just opened a read channel, release it */
pcm_chnrelease(rdch);
}
@ -264,17 +262,6 @@ dsp_open(dev_t i_dev, int flags, int mode, struct thread *td)
return EBUSY;
}
/* got a channel, already locked for us */
} else {
/* already open for write */
if (rdch && (flags & FREAD)) {
/* just opened a read channel, release it */
pcm_chnrelease(rdch);
}
/* exit */
pcm_unlock(d);
splx(s);
return EBUSY;
}
}
i_dev->si_drv1 = rdch;
@ -283,7 +270,6 @@ dsp_open(dev_t i_dev, int flags, int mode, struct thread *td)
/* finished with snddev, new channels still locked */
/* bump refcounts, reset and unlock any channels that we just opened */
if (rdch) {
if (flags & FREAD) {
if (chn_reset(rdch, fmt)) {
pcm_lock(d);
@ -296,28 +282,25 @@ dsp_open(dev_t i_dev, int flags, int mode, struct thread *td)
}
if (flags & O_NONBLOCK)
rdch->flags |= CHN_F_NBIO;
} else
CHN_LOCK(rdch);
pcm_chnref(rdch, 1);
CHN_UNLOCK(rdch);
}
if (wrch) {
if (flags & FWRITE) {
if (chn_reset(wrch, fmt)) {
pcm_lock(d);
pcm_chnrelease(wrch);
if (rdch && (flags & FREAD))
if (flags & FREAD) {
CHN_LOCK(rdch);
pcm_chnref(rdch, -1);
pcm_chnrelease(rdch);
CHN_UNLOCK(rdch);
}
pcm_unlock(d);
splx(s);
return ENODEV;
}
if (flags & O_NONBLOCK)
wrch->flags |= CHN_F_NBIO;
} else
CHN_LOCK(wrch);
pcm_chnref(wrch, 1);
CHN_UNLOCK(wrch);
}