[PATCH net] net: ethernet: microchip: lan743x: Fix dma allocation failure by using dma_set_mask_and_coherent

The dma failure was reported in the raspberry pi github (issue #4117).
https://github.com/raspberrypi/linux/issues/4117
The use of dma_set_mask_and_coherent fixes the issue.
Tested on 32/64-bit raspberry pi CM4 and 64-bit ubuntu x86 PC with EVB-LAN7430.

Fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: Yuiko Oshino <redacted>
---
 drivers/net/ethernet/microchip/lan743x_main.c | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/net/ethernet/microchip/lan743x_main.c b/drivers/net/ethernet/microchip/lan743x_main.c
index 03d02403c19e..6ffcd1b06f2d 100644
--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c

@@ -1743,6 +1743,16 @@ static int lan743x_tx_ring_init(struct lan743x_tx *tx)
 		ret = -EINVAL;
 		goto cleanup;
 	}
+	if (dma_set_mask_and_coherent(&tx->adapter->pdev->dev,
+				      DMA_BIT_MASK(64))) {
+		if (dma_set_mask_and_coherent(&tx->adapter->pdev->dev,
+					      DMA_BIT_MASK(32))) {
+			dev_warn(&tx->adapter->pdev->dev,
+				 "lan743x_: No suitable DMA available\n");
+			ret = -ENOMEM;
+			goto cleanup;
+		}
+	}
 	ring_allocation_size = ALIGN(tx->ring_size *
 				     sizeof(struct lan743x_tx_descriptor),
 				     PAGE_SIZE);

@@ -2276,6 +2286,16 @@ static int lan743x_rx_ring_init(struct lan743x_rx *rx)
 		ret = -EINVAL;
 		goto cleanup;
 	}
+	if (dma_set_mask_and_coherent(&rx->adapter->pdev->dev,
+				      DMA_BIT_MASK(64))) {
+		if (dma_set_mask_and_coherent(&rx->adapter->pdev->dev,
+					      DMA_BIT_MASK(32))) {
+			dev_warn(&rx->adapter->pdev->dev,
+				 "lan743x_: No suitable DMA available\n");
+			ret = -ENOMEM;
+			goto cleanup;
+		}
+	}
 	ring_allocation_size = ALIGN(rx->ring_size *
 				     sizeof(struct lan743x_rx_descriptor),
 				     PAGE_SIZE);

-- 
2.25.1

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller [off-list ref]:

On Fri, 22 Oct 2021 11:53:43 -0400 you wrote:

The dma failure was reported in the raspberry pi github (issue #4117).
https://github.com/raspberrypi/linux/issues/4117
The use of dma_set_mask_and_coherent fixes the issue.
Tested on 32/64-bit raspberry pi CM4 and 64-bit ubuntu x86 PC with EVB-LAN7430.

Fixes: 23f0703c125b ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: Yuiko Oshino <redacted>

[...]

Here is the summary with links:
  - [net] net: ethernet: microchip: lan743x: Fix dma allocation failure by using dma_set_mask_and_coherent
    https://git.kernel.org/netdev/net/c/95a359c95533

You are awesome, thank you!
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