From: Christian Lamparter <chunkeey@googlemail.com>
Date: Fri, 11 Feb 2011 00:48:42 +0000 (+0100)
Subject: p54pci: update receive dma buffers before and after processing
X-Git-Tag: firefly_0821_release~10186^2~400
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=98451bc260c93f3b9acd57bcb665525b5eac213f;p=firefly-linux-kernel-4.4.55.git
p54pci: update receive dma buffers before and after processing
commit 0bf719dfdecc5552155cbec78e49fa06e531e35c upstream.
Documentation/DMA-API-HOWTO.txt states:
"DMA transfers need to be synced properly in order for
the cpu and device to see the most uptodate and correct
copy of the DMA buffer."
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
diff --git a/drivers/net/wireless/p54/p54pci.c b/drivers/net/wireless/p54/p54pci.c
index 3df13f590182..d21fb27ca1f9 100644
--- a/drivers/net/wireless/p54/p54pci.c
+++ b/drivers/net/wireless/p54/p54pci.c
@@ -198,6 +198,7 @@ static void p54p_check_rx_ring(struct ieee80211_hw *dev, u32 *index,
while (i != idx) {
u16 len;
struct sk_buff *skb;
+ dma_addr_t dma_addr;
desc = &ring[i];
len = le16_to_cpu(desc->len);
skb = rx_buf[i];
@@ -215,17 +216,20 @@ static void p54p_check_rx_ring(struct ieee80211_hw *dev, u32 *index,
len = priv->common.rx_mtu;
}
+ dma_addr = le32_to_cpu(desc->host_addr);
+ pci_dma_sync_single_for_cpu(priv->pdev, dma_addr,
+ priv->common.rx_mtu + 32, PCI_DMA_FROMDEVICE);
skb_put(skb, len);
if (p54_rx(dev, skb)) {
- pci_unmap_single(priv->pdev,
- le32_to_cpu(desc->host_addr),
- priv->common.rx_mtu + 32,
- PCI_DMA_FROMDEVICE);
+ pci_unmap_single(priv->pdev, dma_addr,
+ priv->common.rx_mtu + 32, PCI_DMA_FROMDEVICE);
rx_buf[i] = NULL;
- desc->host_addr = 0;
+ desc->host_addr = cpu_to_le32(0);
} else {
skb_trim(skb, 0);
+ pci_dma_sync_single_for_device(priv->pdev, dma_addr,
+ priv->common.rx_mtu + 32, PCI_DMA_FROMDEVICE);
desc->len = cpu_to_le16(priv->common.rx_mtu + 32);
}