Re: [PATCH] dma-mapping: fix sync_single_range_* DMA debugging

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

On Oct 15 Clemens Ladisch wrote:
> Commit 5fd75a7850b5 (dma-mapping: remove unnecessary sync_single_range_*
> in dma_map_ops) unified not only the dma_map_ops but also the
> corresponding debug_dma_sync_* calls.  This led to spurious WARN()ings
> like the following because the DMA debug code was no longer able to
> detect the DMA buffer base address without the separate offset parameter:
> 
> WARNING: at lib/dma-debug.c:911 check_sync+0xce/0x446()
> firewire_ohci 0000:04:00.0: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x00000000cedaa400] [size=1024 bytes]
> Call Trace: ...
>  [<ffffffff811326a5>] check_sync+0xce/0x446
>  [<ffffffff81132ad9>] debug_dma_sync_single_for_device+0x39/0x3b
>  [<ffffffffa01d6e6a>] ohci_queue_iso+0x4f3/0x77d [firewire_ohci]
>  ...
> 
> To fix this, unshare the sync_single_* and sync_single_range_*
> implementations so that we are able to call the correct debug_dma_sync_*
> functions.
> 
> Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

Reviewed-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

> ---
>  include/asm-generic/dma-mapping-common.h |   14 ++++++++++++--
>  1 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
> index 0c80bb3..9e31514 100644
> --- a/include/asm-generic/dma-mapping-common.h
> +++ b/include/asm-generic/dma-mapping-common.h
> @@ -123,7 +123,12 @@ static inline void dma_sync_single_range_for_cpu(struct device *dev,
>  						 size_t size,
>  						 enum dma_data_direction dir)
>  {
> -	dma_sync_single_for_cpu(dev, addr + offset, size, dir);
> +	struct dma_map_ops *ops = get_dma_ops(dev);
> +
> +	BUG_ON(!valid_dma_direction(dir));
> +	if (ops->sync_single_for_cpu)
> +		ops->sync_single_for_cpu(dev, addr + offset, size, dir);
> +	debug_dma_sync_single_range_for_cpu(dev, addr, offset, size, dir);
>  }
> 
>  static inline void dma_sync_single_range_for_device(struct device *dev,
> @@ -132,7 +137,12 @@ static inline void dma_sync_single_range_for_device(struct device *dev,
>  						    size_t size,
>  						    enum dma_data_direction dir)
>  {
> -	dma_sync_single_for_device(dev, addr + offset, size, dir);
> +	struct dma_map_ops *ops = get_dma_ops(dev);
> +
> +	BUG_ON(!valid_dma_direction(dir));
> +	if (ops->sync_single_for_device)
> +		ops->sync_single_for_device(dev, addr + offset, size, dir);
> +	debug_dma_sync_single_range_for_device(dev, addr, offset, size, dir);
>  }
> 
>  static inline void



-- 
Stefan Richter
-=====-==-== =-=- =--==
http://arcgraph.de/sr/