Re: [alsa-devel] 2.6.26.[6|7]-rt11, alsa rawmidi, seq hang (tasklet_hi_schedule?)

Takashi Iwai
2008-11-19T11:44:37Z

At Fri, 14 Nov 2008 10:57:10 -0800,
Fernando Lopez-Lezcano wrote:
>
> On Fri, 2008-11-14 at 09:15 +0100, Clemens Ladisch wrote:
> > Fernando Lopez-Lezcano wrote:
> > > I've been trying to follow the printk crumbs without much success.
> > > AFAICT it all points to tasklet_hi_schedule ...
> >
> > I don't have -rt, but if the error is similar to the old one you might
> > try replacing tasklet_hi_schedule with tasklet_schedule.
>
> YES YES!! __Thanks__ for the suggestion, it WORKED!!
>
> Maybe the kernel rt gurus should look around and see _why_ the problem
> was happening in the first place. There are not that many uses of
> tasklet_hi_schedule in the kernel tree I'm working with:
(snip)
> Maybe other drivers are affected as well by the rt patch.
> What is the difference between tasklet_hi_schedule and tasklet_schedule?

AFAIK, tasklet_hi_schedule() uses another softirq vector with the
highest priority (the first item to be scanned).

Regarding the ALSA codes, there is no big reason to use hi_* version.
Could you check the patch below and see whether you get any
regressions?

thanks,

Takashi

---
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c
index 39672f6..002777b 100644
--- a/sound/core/rawmidi.c
+++ b/sound/core/rawmidi.c
@@ -151,7 +151,7 @@ static inline void snd_rawmidi_output_trigger(struct snd_rawmidi_substream *subs
if (!substream->opened)
return;
if (up) {
- tasklet_hi_schedule(&substream->runtime->tasklet);
+ tasklet_schedule(&substream->runtime->tasklet);
} else {
tasklet_kill(&substream->runtime->tasklet);
substream->ops->trigger(substream, 0);
@@ -908,7 +908,7 @@ int snd_rawmidi_receive(struct snd_rawmidi_substream *substream,
}
if (result > 0) {
if (runtime->event)
- tasklet_hi_schedule(&runtime->tasklet);
+ tasklet_schedule(&runtime->tasklet);
else if (snd_rawmidi_ready(substream))
wake_up(&runtime->sleep);
}
diff --git a/sound/core/rtctimer.c b/sound/core/rtctimer.c
index 51e64e3..0851cd1 100644
--- a/sound/core/rtctimer.c
+++ b/sound/core/rtctimer.c
@@ -118,7 +118,7 @@ static void rtctimer_tasklet(unsigned long data)
*/
static void rtctimer_interrupt(void *private_data)
{
- tasklet_hi_schedule(private_data);
+ tasklet_schedule(private_data);
}

diff --git a/sound/core/timer.c b/sound/core/timer.c
index c584408..7965320 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -743,7 +743,7 @@ void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
spin_unlock_irqrestore(&timer->lock, flags);

if (use_tasklet)
- tasklet_hi_schedule(&timer->task_queue);
+ tasklet_schedule(&timer->task_queue);
}

/*
diff --git a/sound/drivers/vx/vx_core.c b/sound/drivers/vx/vx_core.c
index 473b07f..14e3354 100644
--- a/sound/drivers/vx/vx_core.c
+++ b/sound/drivers/vx/vx_core.c
@@ -548,7 +548,7 @@ irqreturn_t snd_vx_irq_handler(int irq, void *dev)
(chip->chip_status & VX_STAT_IS_STALE))
return IRQ_NONE;
if (! vx_test_and_ack(chip))
- tasklet_hi_schedule(&chip->tq);
+ tasklet_schedule(&chip->tq);
return IRQ_HANDLED;
}

diff --git a/sound/drivers/vx/vx_pcm.c b/sound/drivers/vx/vx_pcm.c
index 27de574..6644d00 100644
--- a/sound/drivers/vx/vx_pcm.c
+++ b/sound/drivers/vx/vx_pcm.c
@@ -823,7 +823,7 @@ static int vx_pcm_trigger(struct snd_pcm_substream *subs, int cmd)
* we trigger the pipe using tasklet, so that the interrupts are
* issued surely after the trigger is completed.
*/
- tasklet_hi_schedule(&pipe->start_tq);
+ tasklet_schedule(&pipe->start_tq);
chip->pcm_running++;
pipe->running = 1;
break;
diff --git a/sound/pci/es1968.c b/sound/pci/es1968.c
index 20ee759..e9c3794 100644
--- a/sound/pci/es1968.c
+++ b/sound/pci/es1968.c
@@ -1953,7 +1953,7 @@ static irqreturn_t snd_es1968_interrupt(int irq, void *dev_id)
outw(inw(chip->io_port + 4) & 1, chip->io_port + 4);

if (event & ESM_HWVOL_IRQ)
- tasklet_hi_schedule(&chip->hwvol_tq); /* we'll do this later */
+ tasklet_schedule(&chip->hwvol_tq); /* we'll do this later */

/* else ack 'em all, i imagine */
outb(0xFF, chip->io_port + 0x1A);
diff --git a/sound/pci/maestro3.c b/sound/pci/maestro3.c
index 9ff3f9e..59bbaf8 100644
--- a/sound/pci/maestro3.c
+++ b/sound/pci/maestro3.c
@@ -1670,7 +1670,7 @@ static irqreturn_t snd_m3_interrupt(int irq, void *dev_id)
return IRQ_NONE;

if (status & HV_INT_PENDING)
- tasklet_hi_schedule(&chip->hwvol_tq);
+ tasklet_schedule(&chip->hwvol_tq);

/*
* ack an assp int if its running
diff --git a/sound/pci/mixart/mixart_core.c b/sound/pci/mixart/mixart_core.c
index b9a06c2..d3350f3 100644
--- a/sound/pci/mixart/mixart_core.c
+++ b/sound/pci/mixart/mixart_core.c
@@ -550,7 +550,7 @@ irqreturn_t snd_mixart_interrupt(int irq, void *dev_id)
mgr->msg_fifo[mgr->msg_fifo_writeptr] = msg;
mgr->msg_fifo_writeptr++;
mgr->msg_fifo_writeptr %= MSG_FIFO_SIZE;
- tasklet_hi_schedule(&mgr->msg_taskq);
+ tasklet_schedule(&mgr->msg_taskq);
}
spin_unlock(&mgr->msg_lock);
break;
diff --git a/sound/pci/pcxhr/pcxhr.c b/sound/pci/pcxhr/pcxhr.c
index 73de6e9..8309d44 100644
--- a/sound/pci/pcxhr/pcxhr.c
+++ b/sound/pci/pcxhr/pcxhr.c
@@ -653,7 +653,7 @@ static int pcxhr_trigger(struct snd_pcm_substream *subs, int cmd)
PCXHR_STREAM_STATUS_SCHEDULE_RUN;
snd_pcm_trigger_done(s, subs);
}
- tasklet_hi_schedule(&chip->mgr->trigger_taskq);
+ tasklet_schedule(&chip->mgr->trigger_taskq);
} else {
stream = subs->runtime->private_data;
snd_printdd("Only one Substream %c %d\n",
diff --git a/sound/pci/pcxhr/pcxhr_core.c b/sound/pci/pcxhr/pcxhr_core.c
index 7143259..4a5481f 100644
--- a/sound/pci/pcxhr/pcxhr_core.c
+++ b/sound/pci/pcxhr/pcxhr_core.c
@@ -1213,7 +1213,7 @@ irqreturn_t pcxhr_interrupt(int irq, void *dev_id)
mgr->dsp_time_last = PCXHR_DSP_TIME_INVALID;

mgr->src_it_dsp = reg;
- tasklet_hi_schedule(&mgr->msg_taskq);
+ tasklet_schedule(&mgr->msg_taskq);
}
#ifdef CONFIG_SND_DEBUG_VERBOSE
if (reg & PCXHR_FATAL_DSP_ERR)
diff --git a/sound/pci/riptide/riptide.c b/sound/pci/riptide/riptide.c
index e9f0706..1d0eeb1 100644
--- a/sound/pci/riptide/riptide.c
+++ b/sound/pci/riptide/riptide.c
@@ -1754,7 +1754,7 @@ snd_riptide_interrupt(int irq, void *dev_id)
if (IS_EOBIRQ(cif->hwport) || IS_EOSIRQ(cif->hwport) ||
IS_EOCIRQ(cif->hwport)) {
chip->handled_irqs++;
- tasklet_hi_schedule(&chip->riptide_tq);
+ tasklet_schedule(&chip->riptide_tq);
}
if (chip->rmidi && IS_MPUIRQ(cif->hwport)) {
chip->handled_irqs++;
diff --git a/sound/pci/rme9652/hdsp.c b/sound/pci/rme9652/hdsp.c
index fdd3be5..44d0c15 100644
--- a/sound/pci/rme9652/hdsp.c
+++ b/sound/pci/rme9652/hdsp.c
@@ -3750,7 +3750,7 @@ static irqreturn_t snd_hdsp_interrupt(int irq, void *dev_id)
}
}
if (hdsp->use_midi_tasklet && schedule)
- tasklet_hi_schedule(&hdsp->midi_tasklet);
+ tasklet_schedule(&hdsp->midi_tasklet);
return IRQ_HANDLED;
}

diff --git a/sound/pci/rme9652/hdspm.c b/sound/pci/rme9652/hdspm.c
index dc5c4ba..71231cf 100644
--- a/sound/pci/rme9652/hdspm.c
+++ b/sound/pci/rme9652/hdspm.c
@@ -3476,7 +3476,7 @@ static irqreturn_t snd_hdspm_interrupt(int irq, void *dev_id)
schedule = 1;
}
if (schedule)
- tasklet_hi_schedule(&hdspm->midi_tasklet);
+ tasklet_schedule(&hdspm->midi_tasklet);
return IRQ_HANDLED;
}

diff --git a/sound/pcmcia/pdaudiocf/pdaudiocf_irq.c b/sound/pcmcia/pdaudiocf/pdaudiocf_irq.c
index fa4b113..ea903c8 100644
--- a/sound/pcmcia/pdaudiocf/pdaudiocf_irq.c
+++ b/sound/pcmcia/pdaudiocf/pdaudiocf_irq.c
@@ -41,7 +41,7 @@ irqreturn_t pdacf_interrupt(int irq, void *dev)
if (stat & PDAUDIOCF_IRQOVR) /* should never happen */
snd_printk(KERN_ERR "PDAUDIOCF SRAM buffer overrun detected!\n");
if (chip->pcm_substream)
- tasklet_hi_schedule(&chip->tq);
+ tasklet_schedule(&chip->tq);
if (!(stat & PDAUDIOCF_IRQAKM))
stat |= PDAUDIOCF_IRQAKM; /* check rate */
}
diff --git a/sound/usb/usbmidi.c b/sound/usb/usbmidi.c
index 5962e4b..6d9f9b1 100644
--- a/sound/usb/usbmidi.c
+++ b/sound/usb/usbmidi.c
@@ -880,7 +880,7 @@ static void snd_usbmidi_output_trigger(struct snd_rawmidi_substream *substream,
snd_rawmidi_transmit_ack(substream, 1);
return;
}
- tasklet_hi_schedule(&port->ep->tasklet);
+ tasklet_schedule(&port->ep->tasklet);
}
}