Re: b44 driver causes panic when using swiotlb

[FUJITA Tomonori]

On Tue, 1 Feb 2011 22:54:56 +0900
FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> wrote:

> On Mon, 31 Jan 2011 10:54:12 -0500
> Chuck Ebbert <cebbert@xxxxxxxxxx> wrote:
> 
> > The b44 driver is triggering this panic in swiotlb_map_page():
> > 
> >         if (!dma_capable(dev, dev_addr, size))
> >                 panic("map_single: bounce buffer is not DMA'ble");
> > 
> > The kernel log says the bounce buffers are at 0xdb400000, but b44 can
> > only do DMA to the first 1GB of memory:
> 
> Can you try this? b44 has the own bouncing mechanism so if swiotlb
> returns an error, the driver can allocate an appropriate buffer.
> 
> diff --git a/lib/swiotlb.c b/lib/swiotlb.c
> index c47bbe1..93ca08b 100644
> --- a/lib/swiotlb.c
> +++ b/lib/swiotlb.c
> @@ -686,8 +686,10 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
>  	/*
>  	 * Ensure that the address returned is DMA'ble
>  	 */
> -	if (!dma_capable(dev, dev_addr, size))
> -		panic("map_single: bounce buffer is not DMA'ble");
> +	if (!dma_capable(dev, dev_addr, size)) {
> +		swiotlb_tbl_unmap_single(dev, map, size, dir);
> +		dev_addr = swiotlb_virt_to_bus(dev, io_tlb_overflow_buffer);
> +	}
>  
>  	return dev_addr;
>  }

Ping, any chance to try this?


Thanks,
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