diff --git a/drivers/misc/rp1-pio.c b/drivers/misc/rp1-pio.c
index 24c1cc5f887b77..e9a437bcc0b2fa 100644
--- a/drivers/misc/rp1-pio.c
+++ b/drivers/misc/rp1-pio.c
@@ -50,7 +50,9 @@
 #define RP1_PIO_FIFO_RX2	0x18
 #define RP1_PIO_FIFO_RX3	0x1c
 
-#define RP1_PIO_DMACTRL_DEFAULT	0x80000104
+#define RP1_PIO_FIFO_DEPTH	8
+
+#define RP1_PIO_DMACTRL_DEFAULT	0x80000100
 
 #define HANDLER(_n, _f) \
 	[_IOC_NR(PIO_IOC_ ## _n)] = { #_n, rp1_pio_ ## _f, _IOC_SIZE(PIO_IOC_ ## _n) }
@@ -613,7 +615,7 @@ static int rp1_pio_sm_config_xfer_internal(struct rp1_pio_client *client, uint s
 	struct dma_slave_config config = {};
 	struct dma_slave_caps dma_caps;
 	phys_addr_t fifo_addr;
-	struct dma_info *dma;
+	struct dma_info *dma = NULL;
 	uint32_t dma_mask;
 	char chan_name[4];
 	int ret = 0;
@@ -627,14 +629,17 @@ static int rp1_pio_sm_config_xfer_internal(struct rp1_pio_client *client, uint s
 
 	dma_mask = 1 << (sm * 2 + dir);
 
-	dma = &pio->dma_configs[sm][dir];
-
 	spin_lock(&pio->lock);
-	if (pio->claimed_dmas & dma_mask)
-		rp1_pio_sm_dma_free(dev, dma);
-	pio->claimed_dmas |= dma_mask;
-	client->claimed_dmas |= dma_mask;
+	if (!(pio->claimed_dmas & dma_mask & ~client->claimed_dmas)) {
+		dma = &pio->dma_configs[sm][dir];
+		if (client->claimed_dmas & dma_mask)
+			rp1_pio_sm_dma_free(dev, dma);
+		pio->claimed_dmas |= dma_mask;
+		client->claimed_dmas |= dma_mask;
+	}
 	spin_unlock(&pio->lock);
+	if (!dma)
+		return -EBUSY;
 
 	dma->buf_size = buf_size;
 	/* Round up the allocations */
@@ -679,6 +684,8 @@ static int rp1_pio_sm_config_xfer_internal(struct rp1_pio_client *client, uint s
 	config.direction = (dir == RP1_PIO_DIR_TO_SM) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
 	dma_caps.max_burst = 4;
 	dma_get_slave_caps(dma->chan, &dma_caps);
+	if (dma_caps.max_burst > RP1_PIO_FIFO_DEPTH)
+		dma_caps.max_burst = RP1_PIO_FIFO_DEPTH;
 	if (dir == RP1_PIO_DIR_TO_SM)
 		config.dst_maxburst = dma_caps.max_burst;
 	else
@@ -690,9 +697,11 @@ static int rp1_pio_sm_config_xfer_internal(struct rp1_pio_client *client, uint s
 
 	set_dmactrl_args.sm = sm;
 	set_dmactrl_args.is_tx = (dir == RP1_PIO_DIR_TO_SM);
-	set_dmactrl_args.ctrl = RP1_PIO_DMACTRL_DEFAULT;
 	if (dir == RP1_PIO_DIR_FROM_SM)
-		set_dmactrl_args.ctrl = (RP1_PIO_DMACTRL_DEFAULT & ~0x1f) | 1;
+		set_dmactrl_args.ctrl = RP1_PIO_DMACTRL_DEFAULT | config.src_maxburst;
+	else
+		set_dmactrl_args.ctrl = RP1_PIO_DMACTRL_DEFAULT |
+					(RP1_PIO_FIFO_DEPTH - config.dst_maxburst);
 
 	ret = rp1_pio_sm_set_dmactrl(client, &set_dmactrl_args);
 	if (ret)
@@ -873,13 +882,20 @@ static int rp1_pio_sm_xfer_data32_user(struct rp1_pio_client *client, void *para
 {
 	struct rp1_pio_sm_xfer_data32_args *args = param;
 	struct rp1_pio_device *pio = client->pio;
-	struct dma_info *dma;
+	struct dma_info *dma = NULL;
+	uint32_t dma_mask;
 
 	if (args->sm >= RP1_PIO_SMS_COUNT || args->dir >= RP1_PIO_DIR_COUNT ||
 	    !args->data_bytes || !args->data)
 		return -EINVAL;
 
-	dma = &pio->dma_configs[args->sm][args->dir];
+	dma_mask = 1 << (args->sm * 2 + args->dir);
+	spin_lock(&pio->lock);
+	if (client->claimed_dmas & dma_mask)
+		dma = &pio->dma_configs[args->sm][args->dir];
+	spin_unlock(&pio->lock);
+	if (!dma)
+		return -EINVAL;
 
 	if (args->dir == RP1_PIO_DIR_TO_SM)
 		return rp1_pio_sm_tx_user(pio, dma, args->data, args->data_bytes);