Re: [PATCH 10/18] smc911x: pass struct device to DMA API functions

From: Robin Murphy
Date: Fri Feb 01 2019 - 09:14:40 EST

On 01/02/2019 08:47, Christoph Hellwig wrote:
The DMA API generally relies on a struct device to work properly, and
only barely works without one for legacy reasons. Pass the easily
available struct device from the platform_device to remedy this.

Hmm, as far as I'm aware these are PIO chips with external DMA handshaking, rather than actual DMA masters...

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
drivers/net/ethernet/smsc/smc911x.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/smsc/smc911x.c b/drivers/net/ethernet/smsc/smc911x.c
index 8355dfbb8ec3..b550e624500d 100644
--- a/drivers/net/ethernet/smsc/smc911x.c
+++ b/drivers/net/ethernet/smsc/smc911x.c
@@ -1188,7 +1188,7 @@ smc911x_tx_dma_irq(void *data)
DBG(SMC_DEBUG_TX | SMC_DEBUG_DMA, dev, "TX DMA irq handler\n");
BUG_ON(skb == NULL);
- dma_unmap_single(NULL, tx_dmabuf, tx_dmalen, DMA_TO_DEVICE);
+ dma_unmap_single(lp->dev, tx_dmabuf, tx_dmalen, DMA_TO_DEVICE); while the wrong device is still better than no device at all, this probably wants lp->txdma->device->dev.

lp->current_tx_skb = NULL;
@@ -1219,7 +1219,7 @@ smc911x_rx_dma_irq(void *data)
DBG(SMC_DEBUG_FUNC, dev, "--> %s\n", __func__);
DBG(SMC_DEBUG_RX | SMC_DEBUG_DMA, dev, "RX DMA irq handler\n");
- dma_unmap_single(NULL, rx_dmabuf, rx_dmalen, DMA_FROM_DEVICE);
+ dma_unmap_single(lp->dev, rx_dmabuf, rx_dmalen, DMA_FROM_DEVICE);

And equivalently for rxdma here. However, given that this all seems only relevant to antique ARCH_PXA platforms which are presumably managing to work as-is, it's probably not worth tinkering too much. I'd just stick a note in the commit message that we're still only making these self-consistent with the existing dma_map_single() calls rather than necessarily correct.


BUG_ON(skb == NULL);
lp->current_rx_skb = NULL;
PRINT_PKT(skb->data, skb->len);