dmaengine: dw-axi-dmac: Fix RMW on channel suspend register

Found by comparing the parallel implementation of more than 8 channel support for the StarFive JH7100 SoC by Samin. Fixes: 8243516 ("dmaengine: dw-axi-dmac: support DMAX_NUM_CHANNELS > 8") Co-developed-by: Samin Guo <[email protected]> Signed-off-by: Samin Guo <[email protected]> Signed-off-by: Emil Renner Berthing <[email protected]>
lftan · Dec 27, 2021 · 15f35d6 · 15f35d6
1 parent 1cf4fd3
commit 15f35d6
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -1164,8 +1164,9 @@ static int dma_chan_pause(struct dma_chan *dchan)
 			BIT(chan->id) << DMAC_CHAN_SUSP_WE_SHIFT;
 		axi_dma_iowrite32(chan->chip, DMAC_CHEN, val);
 	} else {
-		val = BIT(chan->id) << DMAC_CHAN_SUSP2_SHIFT |
-		      BIT(chan->id) << DMAC_CHAN_SUSP2_WE_SHIFT;
+		val = axi_dma_ioread32(chan->chip, DMAC_CHSUSPREG);
+		val |= BIT(chan->id) << DMAC_CHAN_SUSP2_SHIFT |
+			BIT(chan->id) << DMAC_CHAN_SUSP2_WE_SHIFT;
 		axi_dma_iowrite32(chan->chip, DMAC_CHSUSPREG, val);
 	}
 
@@ -1190,12 +1191,13 @@ static inline void axi_chan_resume(struct axi_dma_chan *chan)
 {
 	u32 val;
 
-	val = axi_dma_ioread32(chan->chip, DMAC_CHEN);
 	if (chan->chip->dw->hdata->reg_map_8_channels) {
+		val = axi_dma_ioread32(chan->chip, DMAC_CHEN);
 		val &= ~(BIT(chan->id) << DMAC_CHAN_SUSP_SHIFT);
 		val |=  (BIT(chan->id) << DMAC_CHAN_SUSP_WE_SHIFT);
 		axi_dma_iowrite32(chan->chip, DMAC_CHEN, val);
 	} else {
+		val = axi_dma_ioread32(chan->chip, DMAC_CHSUSPREG);
 		val &= ~(BIT(chan->id) << DMAC_CHAN_SUSP2_SHIFT);
 		val |=  (BIT(chan->id) << DMAC_CHAN_SUSP2_WE_SHIFT);
 		axi_dma_iowrite32(chan->chip, DMAC_CHSUSPREG, val);