dmaengine: sh: rz-dmac: Adjust rz_dmac_chan_get_residue() to return error codes

Adjust rz_dmac_chan_get_residue() to return error codes on failure and
provide the residue to callers through the residue parameter. This
prepares the code for the addition of runtime PM support.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Tested-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Link: https://patch.msgid.link/20260526084710.3491480-14-claudiu.beznea@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
index 8fd8a4bd9cc904a2cc24e5ce0168d92c5a80b58a..93394b9934c8967aab55a2f216cba9938a209c6b 100644 (file)
--- a/drivers/dma/sh/rz-dmac.c
+++ b/drivers/dma/sh/rz-dmac.c
@@ -860,8 +860,8 @@ static u32 rz_dmac_calculate_residue_bytes_in_vd(struct rz_dmac_chan *channel,
        return residue;
 }
 
-static u32 rz_dmac_chan_get_residue(struct rz_dmac_chan *channel,
-                                   dma_cookie_t cookie)
+static int rz_dmac_chan_get_residue(struct device *dev, struct rz_dmac_chan *channel,
+                                   dma_cookie_t cookie, u32 *residue)
 {
        struct rz_dmac_desc *desc = NULL;
        struct virt_dma_desc *vd;
@@ -871,7 +871,8 @@ static u32 rz_dmac_chan_get_residue(struct rz_dmac_chan *channel,
        if (vd) {
                /* Descriptor has been issued but not yet processed. */
                desc = to_rz_dmac_desc(vd);
-               return desc->len;
+               *residue = desc->len;
+               return 0;
        } else if (channel->desc && channel->desc->vd.tx.cookie == cookie) {
                /* Descriptor is currently processed. */
                desc = channel->desc;
@@ -879,6 +880,7 @@ static u32 rz_dmac_chan_get_residue(struct rz_dmac_chan *channel,
 
        if (!desc) {
                /* Descriptor was not found. May be already completed by now. */
+               *residue = 0;
                return 0;
        }
 
@@ -901,7 +903,9 @@ static u32 rz_dmac_chan_get_residue(struct rz_dmac_chan *channel,
         * Calculate number of bytes transferred in processing virtual descriptor.
         * One virtual descriptor can have many lmdesc.
         */
-       return crtb + rz_dmac_calculate_residue_bytes_in_vd(channel, desc, crla);
+       *residue = crtb + rz_dmac_calculate_residue_bytes_in_vd(channel, desc, crla);
+
+       return 0;
 }
 
 static enum dma_status rz_dmac_tx_status(struct dma_chan *chan,
@@ -909,15 +913,20 @@ static enum dma_status rz_dmac_tx_status(struct dma_chan *chan,
                                         struct dma_tx_state *txstate)
 {
        struct rz_dmac_chan *channel = to_rz_dmac_chan(chan);
+       struct rz_dmac *dmac = to_rz_dmac(chan->device);
        enum dma_status status;
        u32 residue;
 
        scoped_guard(spinlock_irqsave, &channel->vc.lock) {
+               int ret;
+
                status = dma_cookie_status(chan, cookie, txstate);
                if (status == DMA_COMPLETE || !txstate)
                        return status;
 
-               residue = rz_dmac_chan_get_residue(channel, cookie);
+               ret = rz_dmac_chan_get_residue(dmac->dev, channel, cookie, &residue);
+               if (ret)
+                       return DMA_ERROR;
 
                if (status == DMA_IN_PROGRESS && rz_dmac_chan_is_paused(channel))
                        status = DMA_PAUSED;