ALSA: hda: Poll SDxFIFOS after programming SDxFMT

Software shall read SDxFIFOS calculated by the hardware and notify if
invalid value is programmed before continuing the stream preparation.
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20230926080623.43927-2-cezary.rojewski@intel.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/hda_register.h

@@ -91,6 +91,8 @@ enum { SDI0, SDI1, SDI2, SDI3, SDO0, SDO1, SDO2, SDO3 };
 #define AZX_REG_SD_BDLPL		0x18
 #define AZX_REG_SD_BDLPU		0x1c
 
+#define AZX_SD_FIFOSIZE_MASK		GENMASK(15, 0)
+
 /* GTS registers */
 #define AZX_REG_LLCH			0x14
 

include/sound/hdaudio.h

@@ -624,6 +624,9 @@ int snd_hdac_stream_set_lpib(struct hdac_stream *azx_dev, u32 value);
 #define snd_hdac_stream_readb_poll(dev, reg, val, cond, delay_us, timeout_us) \
 	read_poll_timeout_atomic(snd_hdac_reg_readb, val, cond, delay_us, timeout_us, \
 				 false, (dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg)
+#define snd_hdac_stream_readw_poll(dev, reg, val, cond, delay_us, timeout_us) \
+	read_poll_timeout_atomic(snd_hdac_reg_readw, val, cond, delay_us, timeout_us, \
+				 false, (dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg)
 #define snd_hdac_stream_readl_poll(dev, reg, val, cond, delay_us, timeout_us) \
 	read_poll_timeout_atomic(snd_hdac_reg_readl, val, cond, delay_us, timeout_us, \
 				 false, (dev)->bus, (dev)->sd_addr + AZX_REG_ ## reg)

sound/hda/hdac_stream.c

@@ -258,6 +258,8 @@ int snd_hdac_stream_setup(struct hdac_stream *azx_dev)
 	struct hdac_bus *bus = azx_dev->bus;
 	struct snd_pcm_runtime *runtime;
 	unsigned int val;
+	u16 reg;
+	int ret;
 
 	if (azx_dev->substream)
 		runtime = azx_dev->substream->runtime;
@@ -300,6 +302,12 @@ int snd_hdac_stream_setup(struct hdac_stream *azx_dev)
 	/* set the interrupt enable bits in the descriptor control register */
 	snd_hdac_stream_updatel(azx_dev, SD_CTL, 0, SD_INT_MASK);
 
+	/* Once SDxFMT is set, the controller programs SDxFIFOS to non-zero value. */
+	ret = snd_hdac_stream_readw_poll(azx_dev, SD_FIFOSIZE, reg, reg & AZX_SD_FIFOSIZE_MASK,
+					 3, 300);
+	if (ret)
+		dev_dbg(bus->dev, "polling SD_FIFOSIZE 0x%04x failed: %d\n",
+			AZX_REG_SD_FIFOSIZE, ret);
 	azx_dev->fifo_size = snd_hdac_stream_readw(azx_dev, SD_FIFOSIZE) + 1;
 
 	/* when LPIB delay correction gives a small negative value,