2 files changed, 22 insertions, 13 deletions

diff --git a/sound/soc/stm/stm32_sai.c b/sound/soc/stm/stm32_sai.c
index 1258bef4dcb3..5fe878ace605 100644
--- a/sound/soc/stm/stm32_sai.c
+++ b/sound/soc/stm/stm32_sai.c
@@ -85,7 +85,7 @@ static int stm32_sai_probe(struct platform_device *pdev)
 	}
 
 	/* reset */
-	rst = reset_control_get_exclusive(&pdev->dev, NULL);
+	rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
 	if (!IS_ERR(rst)) {
 		reset_control_assert(rst);
 		udelay(2);
diff --git a/sound/soc/stm/stm32_sai_sub.c b/sound/soc/stm/stm32_sai_sub.c
index 90d439613899..dde8ddf9e777 100644
--- a/sound/soc/stm/stm32_sai_sub.c
+++ b/sound/soc/stm/stm32_sai_sub.c
@@ -184,7 +184,6 @@ static const struct regmap_config stm32_sai_sub_regmap_config_h7 = {
 static irqreturn_t stm32_sai_isr(int irq, void *devid)
 {
 	struct stm32_sai_sub_data *sai = (struct stm32_sai_sub_data *)devid;
-	struct snd_pcm_substream *substream = sai->substream;
 	struct platform_device *pdev = sai->pdev;
 	unsigned int sr, imr, flags;
 	snd_pcm_state_t status = SNDRV_PCM_STATE_RUNNING;
@@ -199,6 +198,11 @@ static irqreturn_t stm32_sai_isr(int irq, void *devid)
 	regmap_update_bits(sai->regmap, STM_SAI_CLRFR_REGX, SAI_XCLRFR_MASK,
 			   SAI_XCLRFR_MASK);
 
+	if (!sai->substream) {
+		dev_err(&pdev->dev, "Device stopped. Spurious IRQ 0x%x\n", sr);
+		return IRQ_NONE;
+	}
+
 	if (flags & SAI_XIMR_OVRUDRIE) {
 		dev_err(&pdev->dev, "IRQ %s\n",
 			STM_SAI_IS_PLAYBACK(sai) ? "underrun" : "overrun");
@@ -227,9 +231,9 @@ static irqreturn_t stm32_sai_isr(int irq, void *devid)
 	}
 
 	if (status != SNDRV_PCM_STATE_RUNNING) {
-		snd_pcm_stream_lock(substream);
-		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
-		snd_pcm_stream_unlock(substream);
+		snd_pcm_stream_lock(sai->substream);
+		snd_pcm_stop(sai->substream, SNDRV_PCM_STATE_XRUN);
+		snd_pcm_stream_unlock(sai->substream);
 	}
 
 	return IRQ_HANDLED;
@@ -442,12 +446,16 @@ static int stm32_sai_set_config(struct snd_soc_dai *cpu_dai,
 {
 	struct stm32_sai_sub_data *sai = snd_soc_dai_get_drvdata(cpu_dai);
 	int cr1, cr1_mask, ret;
-	int fth = STM_SAI_FIFO_TH_HALF;
 
-	/* FIFO config */
+	/*
+	 * DMA bursts increment is set to 4 words.
+	 * SAI fifo threshold is set to half fifo, to keep enough space
+	 * for DMA incoming bursts.
+	 */
 	regmap_update_bits(sai->regmap, STM_SAI_CR2_REGX,
 			   SAI_XCR2_FFLUSH | SAI_XCR2_FTH_MASK,
-			   SAI_XCR2_FFLUSH | SAI_XCR2_FTH_SET(fth));
+			   SAI_XCR2_FFLUSH |
+			   SAI_XCR2_FTH_SET(STM_SAI_FIFO_TH_HALF));
 
 	/* Mode, data format and channel config */
 	cr1 = SAI_XCR1_PRTCFG_SET(SAI_FREE_PROTOCOL);
@@ -481,10 +489,6 @@ static int stm32_sai_set_config(struct snd_soc_dai *cpu_dai,
 		return ret;
 	}
 
-	/* DMA config */
-	sai->dma_params.maxburst = STM_SAI_FIFO_SIZE * fth / sizeof(u32);
-	snd_soc_dai_set_dma_data(cpu_dai, substream, (void *)&sai->dma_params);
-
 	return 0;
 }
 
@@ -727,7 +731,12 @@ static int stm32_sai_dai_probe(struct snd_soc_dai *cpu_dai)
 	struct stm32_sai_sub_data *sai = dev_get_drvdata(cpu_dai->dev);
 
 	sai->dma_params.addr = (dma_addr_t)(sai->phys_addr + STM_SAI_DR_REGX);
-	sai->dma_params.maxburst = 1;
+	/*
+	 * DMA supports 4, 8 or 16 burst sizes. Burst size 4 is the best choice,
+	 * as it allows bytes, half-word and words transfers. (See DMA fifos
+	 * constraints).
+	 */
+	sai->dma_params.maxburst = 4;
 	/* Buswidth will be set by framework at runtime */
 	sai->dma_params.addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;