From 6ff9c2e7fa8ca63a575792534b63c5092099c286 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Krzysztof=20Ha=C5=82asa?= Date: Sun, 23 Aug 2009 19:02:13 -0700 Subject: [PATCH] E100: fix interaction with swiotlb on X86. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit E100 places it's RX packet descriptors inside skb->data and uses them with bidirectional streaming DMA mapping. Data in descriptors is accessed simultaneously by the chip (writing status and size when a packet is received) and CPU (reading to check if the packet was received). This isn't a valid usage of PCI DMA API, which requires use of the coherent (consistent) memory for such purpose. Unfortunately e100 chips working in "simplified" RX mode have to store received data directly after the descriptor. Fixing the driver to conform to the API would require using unsupported "flexible" RX mode or receiving data into a coherent memory and using CPU to copy it to network buffers. This patch, while not yet making the driver conform to the PCI DMA API, allows it to work correctly on X86 with swiotlb (while not breaking other architectures). Signed-off-by: Krzysztof Hałasa Signed-off-by: David S. Miller --- drivers/net/e100.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/e100.c b/drivers/net/e100.c index 41b648a67fec..3a6735dc9f6a 100644 --- a/drivers/net/e100.c +++ b/drivers/net/e100.c @@ -1899,7 +1899,7 @@ static int e100_rx_indicate(struct nic *nic, struct rx *rx, nic->ru_running = RU_SUSPENDED; pci_dma_sync_single_for_device(nic->pdev, rx->dma_addr, sizeof(struct rfd), - PCI_DMA_BIDIRECTIONAL); + PCI_DMA_FROMDEVICE); return -ENODATA; }