dmaengine: sh: setup_xref error handling

This patch modifies the type of setup_xref from void to int and handles
errors since the function can fail.

`setup_xref` now returns the (eventual) error from
`dmae_set_dmars`|`dmae_set_chcr`, while `shdma_tx_submit` handles the
result, removing the chunks from the queue and marking PM as idle in
case of an error.

Signed-off-by: Thomas Andreatta <thomas.andreatta2000@gmail.com>
Link: https://lore.kernel.org/r/20250827152442.90962-1-thomas.andreatta2000@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: Thomas Andreatta

drivers/dma/sh/shdma-base.c

@@ -129,12 +129,25 @@ static dma_cookie_t shdma_tx_submit(struct dma_async_tx_descriptor *tx)
 			const struct shdma_ops *ops = sdev->ops;
 			dev_dbg(schan->dev, "Bring up channel %d\n",
 				schan->id);
-			/*
-			 * TODO: .xfer_setup() might fail on some platforms.
-			 * Make it int then, on error remove chunks from the
-			 * queue again
-			 */
-			ops->setup_xfer(schan, schan->slave_id);
+
+			ret = ops->setup_xfer(schan, schan->slave_id);
+			if (ret < 0) {
+				dev_err(schan->dev, "setup_xfer failed: %d\n", ret);
+
+				/* Remove chunks from the queue and mark them as idle */
+				list_for_each_entry_safe(chunk, c, &schan->ld_queue, node) {
+					if (chunk->cookie == cookie) {
+						chunk->mark = DESC_IDLE;
+						list_move(&chunk->node, &schan->ld_free);
+					}
+				}
+
+				schan->pm_state = SHDMA_PM_ESTABLISHED;
+				ret = pm_runtime_put(schan->dev);
+
+				spin_unlock_irq(&schan->chan_lock);
+				return ret;
+			}
 
 			if (schan->pm_state == SHDMA_PM_PENDING)
 				shdma_chan_xfer_ld_queue(schan);

drivers/dma/sh/shdmac.c

@@ -300,21 +300,30 @@ static bool sh_dmae_channel_busy(struct shdma_chan *schan)
 	return dmae_is_busy(sh_chan);
 }
 
-static void sh_dmae_setup_xfer(struct shdma_chan *schan,
-			       int slave_id)
+static int sh_dmae_setup_xfer(struct shdma_chan *schan, int slave_id)
 {
 	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
 						    shdma_chan);
 
+	int ret = 0;
 	if (slave_id >= 0) {
 		const struct sh_dmae_slave_config *cfg =
 			sh_chan->config;
 
-		dmae_set_dmars(sh_chan, cfg->mid_rid);
-		dmae_set_chcr(sh_chan, cfg->chcr);
+		ret = dmae_set_dmars(sh_chan, cfg->mid_rid);
+		if (ret < 0)
+			goto END;
+
+		ret = dmae_set_chcr(sh_chan, cfg->chcr);
+		if (ret < 0)
+			goto END;
+
 	} else {
 		dmae_init(sh_chan);
 	}
+
+END:
+	return ret;
 }
 
 /*

include/linux/shdma-base.h

@@ -96,7 +96,7 @@ struct shdma_ops {
 	int (*desc_setup)(struct shdma_chan *, struct shdma_desc *,
 			  dma_addr_t, dma_addr_t, size_t *);
 	int (*set_slave)(struct shdma_chan *, int, dma_addr_t, bool);
-	void (*setup_xfer)(struct shdma_chan *, int);
+	int (*setup_xfer)(struct shdma_chan *, int);
 	void (*start_xfer)(struct shdma_chan *, struct shdma_desc *);
 	struct shdma_desc *(*embedded_desc)(void *, int);
 	bool (*chan_irq)(struct shdma_chan *, int);