Re: Strange network timeouts w/ 2.6.30.5

From: Krzysztof Halasa
Date: Thu Aug 20 2009 - 09:45:39 EST


Walt Holman <walt@xxxxxxxxxxxxxx> writes:

> dmesg is attached. This box does have >2GB Ram (6GB total). The dmesg
> will show e100 init'd 3 times since the first is the stock modprobe,
> 2nd was forced with use_io and the 3rd modprobe was after reverting
> the patch.

You most probably can't test without swiotlb (RAM has to be limited to
2 GB or so), can you? That would (dis)prove my theory. Alternatively (or
better), a test on IOMMU-equipped system would do.

Since swiotlb is x86-only thing (though other 64-bit archs may have
something similar), I think the correct work around is to enable the
"for_device" handoff on !X86.

Something like maybe:

Signed-off-by: Krzysztof Hałasa <khc@xxxxxxxxx>

diff --git a/drivers/net/e100.c b/drivers/net/e100.c
index 014dfb6..b610088 100644
--- a/drivers/net/e100.c
+++ b/drivers/net/e100.c
@@ -1762,9 +1762,12 @@ static int e100_rx_indicate(struct nic *nic, struct rx *rx,

if (ioread8(&nic->csr->scb.status) & rus_no_res)
nic->ru_running = RU_SUSPENDED;
+#ifndef CONFIG_X86
+ /* FIXME interferes with swiotlb. */
pci_dma_sync_single_for_device(nic->pdev, rx->dma_addr,
sizeof(struct rfd),
PCI_DMA_BIDIRECTIONAL);
+#endif
return -ENODATA;
}

--
Krzysztof Halasa
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