asoc: codecs: Avoid spi data transfer during suspend

SPI data transfer can happen during suspend due to race
conditions leading to NOC issues. Synchronize data transfer
and suspend to fix this issue.

Change-Id: Ia5b4d0d16d9bf4fa4a4b73e3509a7d04b45d843f
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>

asoc/codecs/wcd-spi.c

@@ -815,6 +815,15 @@ static int __wcd_spi_data_xfer(struct spi_device *spi,
 		return -EINVAL;
 	}
 
+	WCD_SPI_MUTEX_LOCK(spi, wcd_spi->clk_mutex);
+	if (wcd_spi_is_suspended(wcd_spi)) {
+		dev_dbg(&spi->dev,
+			"%s: SPI suspended, cannot perform transfer\n",
+			__func__);
+		ret = -EIO;
+		goto done;
+	}
+
 	WCD_SPI_MUTEX_LOCK(spi, wcd_spi->xfer_mutex);
 	if (msg->len == WCD_SPI_WORD_BYTE_CNT) {
 		if (xfer_req == WCD_SPI_XFER_WRITE)
@@ -827,7 +836,8 @@ static int __wcd_spi_data_xfer(struct spi_device *spi,
 		ret = wcd_spi_transfer_split(spi, msg, xfer_req);
 	}
 	WCD_SPI_MUTEX_UNLOCK(spi, wcd_spi->xfer_mutex);
-
+done:
+	WCD_SPI_MUTEX_UNLOCK(spi, wcd_spi->clk_mutex);
 	return ret;
 }