lkml.org 
[lkml]   [2010]   [May]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [PATCH] Fix Oops with Atmel SPI
Date
Anders,

I just tested one path, the "if (xfer->rx_buf)...", on
2.6.33 plus the at91 patch
http://maxim.org.za/AT91RM9200/2.6/2.6.33-at91.patch.gz
running on AT91SAM9260.

The test case involved doing i/o via the /dev/mtdblock
interface -- but this only exercises the rx_buf/vmalloc path --
MTD reads a block into the cache-buf to merge the write data. Not
sure that we have any use cases for the tx_buf path using MTD.

-Ian

On Friday 21 May 2010, Andrew Morton wrote:
> On Wed, 19 May 2010 13:05:00 +0200
>
> Anders Larsen <al@alarsen.net> wrote:
> > On 2010-04-22 00:24:10, Andrew Morton wrote:
> > > Finally.. Wouldn't it be better to just fix the atmel SPI
> > > driver so that it doesn't barf when handed vmalloc'ed
> > > memory? Who do we ridicule about that? <checks, adds cc>
> >
> > You mean something like this instead?
>
> That looks simple enough. How do we get it tested,
> changelogged and merged up? Haavard, can you please take a
> look?
>
> > diff --git a/drivers/spi/atmel_spi.c
> > b/drivers/spi/atmel_spi.c index c4e0442..a9ad5e8 100644
> > --- a/drivers/spi/atmel_spi.c
> > +++ b/drivers/spi/atmel_spi.c
> > @@ -352,16 +352,30 @@ atmel_spi_dma_map_xfer(struct
> > atmel_spi *as, struct spi_transfer *xfer)
> >
> > xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS;
> > if (xfer->tx_buf) {
> > - xfer->tx_dma = dma_map_single(dev,
> > - (void *) xfer->tx_buf, xfer->len,
> > - DMA_TO_DEVICE);
> > + if (is_vmalloc_addr(xfer->tx_buf))
> > + xfer->tx_dma = dma_map_page(dev,
> > + vmalloc_to_page(xfer->tx_buf),
> > + (unsigned long)xfer->tx_buf & (PAGE_SIZE-1),
> > + xfer->len,
> > + DMA_TO_DEVICE);
> > + else
> > + xfer->tx_dma = dma_map_single(dev,
> > + (void *) xfer->tx_buf, xfer->len,
> > + DMA_TO_DEVICE);
> > if (dma_mapping_error(dev, xfer->tx_dma))
> > return -ENOMEM;
> > }
> > if (xfer->rx_buf) {
> > - xfer->rx_dma = dma_map_single(dev,
> > - xfer->rx_buf, xfer->len,
> > - DMA_FROM_DEVICE);
> > + if (is_vmalloc_addr(xfer->rx_buf))
> > + xfer->rx_dma = dma_map_page(dev,
> > + vmalloc_to_page(xfer->rx_buf),
> > + (unsigned long)xfer->rx_buf & (PAGE_SIZE-1),
> > + xfer->len,
> > + DMA_FROM_DEVICE);
> > + else
> > + xfer->rx_dma = dma_map_single(dev,
> > + xfer->rx_buf, xfer->len,
> > + DMA_FROM_DEVICE);
> > if (dma_mapping_error(dev, xfer->rx_dma)) {
> > if (xfer->tx_buf)
> > dma_unmap_single(dev,




\
 
 \ /
  Last update: 2010-05-24 17:43    [W:0.085 / U:22.888 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site