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authorLarry Finger <Larry.Finger@lwfinger.net>2011-05-19 10:17:04 -0500
committerJohn W. Linville <linville@tuxdriver.com>2011-05-26 15:43:29 -0400
commita9e12869758430424804dd4332e0d2afdfdf00b0 (patch)
treed56f68c680cec8c376017c66bbe5851f25218252
parent208c72f4fe44fe09577e7975ba0e7fa0278f3d03 (diff)
downloadop-kernel-dev-a9e12869758430424804dd4332e0d2afdfdf00b0.zip
op-kernel-dev-a9e12869758430424804dd4332e0d2afdfdf00b0.tar.gz
rtlwifi: Fix kernel panic resulting from RX buffer allocation failure
To handle amsdu_8k capability, the PCI routine of this driver must allocate receive buffers of order 2. Under heavy load, this causes fragmentation of memory. The present code releases the current buffer before checking to see if a new one is availble. Recovery from allocation failures is not possible, which results in kernel panics. The fix is to reorder the code to check that a new buffer can be allocated before the old one is released. If not possible, the received frame is dropped and the old one is reused. Without this change, it is impossible to transfer a 2 GB file without a kernel panic. Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Stable <stable@vger.kernel.org> [2.6.{37,38,39}] Signed-off-by: John W. Linville <linville@tuxdriver.com>
-rw-r--r--drivers/net/wireless/rtlwifi/pci.c28
1 files changed, 15 insertions, 13 deletions
diff --git a/drivers/net/wireless/rtlwifi/pci.c b/drivers/net/wireless/rtlwifi/pci.c
index a409528..c2b83a5 100644
--- a/drivers/net/wireless/rtlwifi/pci.c
+++ b/drivers/net/wireless/rtlwifi/pci.c
@@ -669,11 +669,6 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw)
&rx_status,
(u8 *) pdesc, skb);
- pci_unmap_single(rtlpci->pdev,
- *((dma_addr_t *) skb->cb),
- rtlpci->rxbuffersize,
- PCI_DMA_FROMDEVICE);
-
skb_put(skb, rtlpriv->cfg->ops->get_desc((u8 *) pdesc,
false,
HW_DESC_RXPKT_LEN));
@@ -690,6 +685,21 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw)
hdr = rtl_get_hdr(skb);
fc = rtl_get_fc(skb);
+ /* try for new buffer - if allocation fails, drop
+ * frame and reuse old buffer
+ */
+ new_skb = dev_alloc_skb(rtlpci->rxbuffersize);
+ if (unlikely(!new_skb)) {
+ RT_TRACE(rtlpriv, (COMP_INTR | COMP_RECV),
+ DBG_DMESG,
+ ("can't alloc skb for rx\n"));
+ goto done;
+ }
+ pci_unmap_single(rtlpci->pdev,
+ *((dma_addr_t *) skb->cb),
+ rtlpci->rxbuffersize,
+ PCI_DMA_FROMDEVICE);
+
if (!stats.crc || !stats.hwerror) {
memcpy(IEEE80211_SKB_RXCB(skb), &rx_status,
sizeof(rx_status));
@@ -758,15 +768,7 @@ static void _rtl_pci_rx_interrupt(struct ieee80211_hw *hw)
rtl_lps_leave(hw);
}
- new_skb = dev_alloc_skb(rtlpci->rxbuffersize);
- if (unlikely(!new_skb)) {
- RT_TRACE(rtlpriv, (COMP_INTR | COMP_RECV),
- DBG_DMESG,
- ("can't alloc skb for rx\n"));
- goto done;
- }
skb = new_skb;
- /*skb->dev = dev; */
rtlpci->rx_ring[rx_queue_idx].rx_buf[rtlpci->
rx_ring
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