On Mon, 16 Mar 2009 12:15:37 -0700
"Luis R. Rodriguez" <mcgrof@xxxxxxxxx> wrote:
> I've run into "PCI-DMA: Out of IOMMU space" messages after loading and
> unloading a module 30 times. The interesting thing is this only
> happens if I have > 4 GB of memory. The box this occurs has AMD Phenom
> quad core CPU so I take it a harware IOMMU is being used. Below are
> example relevant messages with > 4 GB and then < 4 GB of memory. The
> driver I tested this with was ath9k. It could be an issue perhaps with
> ath9k but I am unable to find an issue in our probe/removal.
>
> Could this be an issue with the AMD IOMMU used? Or is it more likely a
> driver issue?
ath9k wants DMA_32BIT_MASK, right? If so, GART IOMMU does nothing on a
system with < 4GB memory since ath9k can access to all the memory
addresses directly. With >4GB memory, GART needs to remap an address
higher than 4GB because ath9k wants DMA_32BIT_MASK.
>From a quick look, ath9k doesn't call pci_unmap_single for rx
buffers. Though I might be wrong because I don't know anything about
the driver.
=
From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Subject: [PATCH] ath9k: fix dma mapping leak of rx buffer
Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
---
drivers/net/wireless/ath9k/recv.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
diff --git a/drivers/net/wireless/ath9k/recv.c b/drivers/net/wireless/ath9k/recv.c
index 462e08c..cd2a1f6 100644
--- a/drivers/net/wireless/ath9k/recv.c
+++ b/drivers/net/wireless/ath9k/recv.c
@@ -322,8 +322,11 @@ void ath_rx_cleanup(struct ath_softc *sc)
list_for_each_entry(bf, &sc->rx.rxbuf, list) {
skb = bf->bf_mpdu;
- if (skb)
+ if (skb) {
+ pci_unmap_single(sc->pdev, bf->bf_buf_addr,
+ sc->rx.bufsize, PCI_DMA_FROMDEVICE);
dev_kfree_skb(skb);
+ }
}
if (sc->rx.rxdma.dd_desc_len != 0)
--
1.6.0.6
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