[PATCH 07/10] can: grcan: set DMA mask for GRCAN and GRCANFD to 32-bit

From: Arun Muthusamy

Date: Tue Nov 18 2025 - 04:25:21 EST


From: Daniel Hellstrom <daniel@xxxxxxxxxxx>

Sets the DMA mask for GRCAN and GRCANFD devices to 32-bit.
Setting the DMA mask and coherent DMA mask to 32-bit ensures proper
memory addressing during DMA operations

Signed-off-by: Arun Muthusamy <arun.muthusamy@xxxxxxxxxxx>
Signed-off-by: Daniel Hellstrom <daniel@xxxxxxxxxxx>
---
drivers/net/can/grcan.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c
index e367581faa57..51a10fae2faf 100644
--- a/drivers/net/can/grcan.c
+++ b/drivers/net/can/grcan.c
@@ -1074,6 +1074,12 @@ static int grcan_allocate_dma_buffers(struct net_device *dev,

/* Extra GRCAN_BUFFER_ALIGNMENT to allow for alignment */
dma->base_size = lsize + ssize + GRCAN_BUFFER_ALIGNMENT;
+
+ /* On 64-bit systems.. GRCAN and GRCANFD can only address 32-bit */
+ if (dma_set_mask_and_coherent(priv->ofdev_dev, DMA_BIT_MASK(32))) {
+ netdev_warn(dev, "No suitable DMA available\n");
+ return -ENOMEM;
+ }
dma->base_buf = dma_alloc_coherent(priv->ofdev_dev,
dma->base_size,
&dma->base_handle,
--
2.51.0