Hi,

I tried forward porting the macb SRAM patches from 2.6.30-at91-exp.4.patch to kernel 2.6.38, but the kernel panics with:

eth0: TX underrun, resetting buffers
kernel BUG at arch/arm/mm/dma-mapping.c:442!

This crash can be fixed with another conditional in macb_tx:

#if !defined(CONFIG_MACB_TX_SRAM)
dma_unmap_single(&bp->pdev->dev, rp->mapping, skb->len, DMA_TO_DEVICE);
#endif

But then I only get to this error line in macb_interrupt:

printk(KERN_ERR "%s: DMA bus error: HRESP not OK\n", dev->name);

Anybody know what has changed in 2.6.38 to make the SRAM patches not work anymore?

Thanks

Hi,
I manually patch this kernel with that patch and add your "patch"

#if !defined(CONFIG_MACB_TX_SRAM)
dma_unmap_single(&bp->pdev->dev, rp->mapping, skb->len, DMA_TO_DEVICE);
#endif

too and it works fine. Before there ware a lot of underruns, about 1000 per 250MB, now about 100 per 250MB.