ALSA: hda: fix to wait for RIRB & CORB DMA to set

If the DMAs are not being quiesced properly, it may lead to
stability issues, so the recommendation is to wait till DMAs are
stopped.

After setting the stop bit of RIRB/CORB DMA, we should wait for
stop bit to be set.

Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
index 8c486235c905253ea0609183d813362a294e42f9..9fee464e5d49772f53db5d4f5a6485ecaa028b10 100644 (file)
--- a/sound/hda/hdac_controller.c
+++ b/sound/hda/hdac_controller.c
@@ -80,6 +80,22 @@ void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus)
 }
 EXPORT_SYMBOL_GPL(snd_hdac_bus_init_cmd_io);
 
+/* wait for cmd dmas till they are stopped */
+static void hdac_wait_for_cmd_dmas(struct hdac_bus *bus)
+{
+       unsigned long timeout;
+
+       timeout = jiffies + msecs_to_jiffies(100);
+       while ((snd_hdac_chip_readb(bus, RIRBCTL) & AZX_RBCTL_DMA_EN)
+               && time_before(jiffies, timeout))
+               udelay(10);
+
+       timeout = jiffies + msecs_to_jiffies(100);
+       while ((snd_hdac_chip_readb(bus, CORBCTL) & AZX_CORBCTL_RUN)
+               && time_before(jiffies, timeout))
+               udelay(10);
+}
+
 /**
  * snd_hdac_bus_stop_cmd_io - clean up CORB/RIRB buffers
  * @bus: HD-audio core bus
@@ -90,6 +106,7 @@ void snd_hdac_bus_stop_cmd_io(struct hdac_bus *bus)
        /* disable ringbuffer DMAs */
        snd_hdac_chip_writeb(bus, RIRBCTL, 0);
        snd_hdac_chip_writeb(bus, CORBCTL, 0);
+       hdac_wait_for_cmd_dmas(bus);
        /* disable unsolicited responses */
        snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_UNSOL, 0);
        spin_unlock_irq(&bus->reg_lock);