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ALSA: hda: Use waitqueue for RIRB in HDA-core helper, too

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This patch implements the same logic that was done for the legacy
HD-audio controller driver by the commit 88452da92b ("ALSA: hda: Use
standard waitqueue for RIRB wakeup") to the HDA-core helper code,
too.  This makes snd_hdac_bus_get_response() waiting for the response
with bus->rirb_wq instead of polling when bus->polling is false.
It'll save both CPU time and response latency.

Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20191212191101.19517-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Iwai 2019-12-12 20:11:00 +01:00
parent 341a79ee8b
commit 89698ed5cc
1 changed files with 14 additions and 2 deletions
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16
sound/hda/hdac_controller.c
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@ -241,30 +241,42 @@ int snd_hdac_bus_get_response(struct hdac_bus *bus, unsigned int addr,
{
unsigned long timeout;
unsigned long loopcounter;
wait_queue_entry_t wait;
init_wait_entry(&wait, 0);
timeout = jiffies + msecs_to_jiffies(1000);
for (loopcounter = 0;; loopcounter++) {
spin_lock_irq(&bus->reg_lock);
if (!bus->polling_mode)
prepare_to_wait(&bus->rirb_wq, &wait,
TASK_UNINTERRUPTIBLE);
if (bus->polling_mode)
snd_hdac_bus_update_rirb(bus);
if (!bus->rirb.cmds[addr]) {
if (res)
*res = bus->rirb.res[addr]; /* the last value */
if (!bus->polling_mode)
finish_wait(&bus->rirb_wq, &wait);
spin_unlock_irq(&bus->reg_lock);
return 0;
}
spin_unlock_irq(&bus->reg_lock);
if (time_after(jiffies, timeout))
break;
if (loopcounter > 3000)
if (!bus->polling_mode) {
schedule_timeout(msecs_to_jiffies(2));
} else if (loopcounter > 3000) {
msleep(2); /* temporary workaround */
else {
} else {
udelay(10);
cond_resched();
}
}
if (!bus->polling_mode)
finish_wait(&bus->rirb_wq, &wait);
return -EIO;
}
EXPORT_SYMBOL_GPL(snd_hdac_bus_get_response);