aboutsummaryrefslogtreecommitdiff
path: root/sound
diff options
context:
space:
mode:
authorDavid Henningsson <david.henningsson@canonical.com>2012-05-04 11:05:55 +0200
committerTakashi Iwai <tiwai@suse.de>2012-05-09 10:22:06 +0200
commit32cf4023e689ad5b3a81a749d8cc99d7f184cb99 (patch)
tree28090820b11f20776b4c12ff6c9fb1cf2eedee93 /sound
parent619a341b78f17fb86d92e89c04612676cd05e26f (diff)
downloadlinux-linaro-stable-32cf4023e689ad5b3a81a749d8cc99d7f184cb99.tar.gz
ALSA: HDA: Lessen CPU usage when waiting for chip to respond
When an IRQ for some reason gets lost, we wait up to a second using udelay, which is CPU intensive. This patch improves the situation by waiting about 30 ms in the CPU intensive mode, then stepping down to using msleep(2) instead. In essence, we trade some granularity in exchange for less CPU consumption when the waiting time is a bit longer. As a result, PulseAudio should no longer be killed by the kernel for taking up to much RT-prio CPU time. At least not for *this* reason. Signed-off-by: David Henningsson <david.henningsson@canonical.com> Tested-by: Arun Raghavan <arun.raghavan@collabora.co.uk> Cc: <stable@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
-rw-r--r--sound/pci/hda/hda_intel.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 6e958bf94191..1f350522bed4 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -783,11 +783,13 @@ static unsigned int azx_rirb_get_response(struct hda_bus *bus,
{
struct azx *chip = bus->private_data;
unsigned long timeout;
+ unsigned long loopcounter;
int do_poll = 0;
again:
timeout = jiffies + msecs_to_jiffies(1000);
- for (;;) {
+
+ for (loopcounter = 0;; loopcounter++) {
if (chip->polling_mode || do_poll) {
spin_lock_irq(&chip->reg_lock);
azx_update_rirb(chip);
@@ -803,7 +805,7 @@ static unsigned int azx_rirb_get_response(struct hda_bus *bus,
}
if (time_after(jiffies, timeout))
break;
- if (bus->needs_damn_long_delay)
+ if (bus->needs_damn_long_delay || loopcounter > 3000)
msleep(2); /* temporary workaround */
else {
udelay(10);