Re: [PATCH] [for 4.14] net: qcom/emac: specify the correct size when mapping a DMA buffer

[David Miller]

From: Timur Tabi 
Date: Fri, 22 Sep 2017 15:32:44 -0500

> When mapping the RX DMA buffers, the driver was accidentally specifying
> zero for the buffer length.  Under normal circumstances, SWIOTLB does not
> need to allocate a bounce buffer, so the address is just mapped without
> checking the size field.  This is why the error was not detected earlier.
> 
> Fixes: b9b17debc69d ("net: emac: emac gigabit ethernet controller driver")
> Cc: sta...@vger.kernel.org
> Signed-off-by: Timur Tabi 

Applied and queued up for -stable, thanks.

[PATCH] [for 4.14] net: qcom/emac: specify the correct size when mapping a DMA buffer

[Timur Tabi]

When mapping the RX DMA buffers, the driver was accidentally specifying
zero for the buffer length.  Under normal circumstances, SWIOTLB does not
need to allocate a bounce buffer, so the address is just mapped without
checking the size field.  This is why the error was not detected earlier.

Fixes: b9b17debc69d ("net: emac: emac gigabit ethernet controller driver")
Cc: sta...@vger.kernel.org
Signed-off-by: Timur Tabi 
---
 drivers/net/ethernet/qualcomm/emac/emac-mac.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/qualcomm/emac/emac-mac.c 
b/drivers/net/ethernet/qualcomm/emac/emac-mac.c
index 0ea3ca09c689..3ed9033e56db 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac-mac.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac-mac.c
@@ -898,7 +898,8 @@ static void emac_mac_rx_descs_refill(struct emac_adapter 
*adpt,
 
curr_rxbuf->dma_addr =
dma_map_single(adpt->netdev->dev.parent, skb->data,
-  curr_rxbuf->length, DMA_FROM_DEVICE);
+  adpt->rxbuf_size, DMA_FROM_DEVICE);
+
ret = dma_mapping_error(adpt->netdev->dev.parent,
curr_rxbuf->dma_addr);
if (ret) {
-- 
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