[alsa-devel] [PATCH 2/2] ALSA: hda: fix to wait for RIRB & CORB DMA to set

[Vinod Koul]

From: Jeeja KP <jeeja.kp at intel.com>

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 at intel.com>
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
---
 sound/hda/hdac_controller.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
index 8c486235c905..cc020c1706e7 100644
--- a/sound/hda/hdac_controller.c
+++ b/sound/hda/hdac_controller.c
@@ -80,6 +80,35 @@ void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus)
 }
 EXPORT_SYMBOL_GPL(snd_hdac_bus_init_cmd_io);
 
+
+/* Stop CORB DMA and poll till they are stopped */
+static void hdac_stop_corb_dma(struct hdac_bus *bus)
+{
+	unsigned long timeout;
+
+	snd_hdac_chip_writew(bus, CORBCTL, 0);
+
+	udelay(3);
+	timeout = jiffies + msecs_to_jiffies(100);
+	while ((snd_hdac_chip_readb(bus, CORBCTL) & AZX_CORBCTL_RUN)
+		&& time_before(jiffies, timeout))
+		udelay(10);
+}
+
+/* Stop RIRB DMA and poll till they are stopped */
+static void hdac_stop_rirb_dma(struct hdac_bus *bus)
+{
+	unsigned long timeout;
+
+	snd_hdac_chip_writew(bus, RIRBCTL, 0);
+
+	udelay(3);
+	timeout = jiffies + msecs_to_jiffies(100);
+	while ((snd_hdac_chip_readb(bus, RIRBCTL) & AZX_RBCTL_DMA_EN)
+		&& time_before(jiffies, timeout))
+		udelay(10);
+}
+
 /**
  * snd_hdac_bus_stop_cmd_io - clean up CORB/RIRB buffers
  * @bus: HD-audio core bus
@@ -88,8 +117,8 @@ void snd_hdac_bus_stop_cmd_io(struct hdac_bus *bus)
 {
 	spin_lock_irq(&bus->reg_lock);
 	/* disable ringbuffer DMAs */
-	snd_hdac_chip_writeb(bus, RIRBCTL, 0);
-	snd_hdac_chip_writeb(bus, CORBCTL, 0);
+	hdac_stop_rirb_dma(bus);
+	hdac_stop_corb_dma(bus);
 	/* disable unsolicited responses */
 	snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_UNSOL, 0);
 	spin_unlock_irq(&bus->reg_lock);
-- 
1.9.1