Re: [PATCH 2/2] parport_pc: set properly the dma_mask for parport_pc device

[Jeff Garzik <jeff@garzik.org>]

Alan Cox wrote:
> From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> 
> parport_pc_probe_port() creates the own 'parport_pc' device if the
> device argument is NULL. Then parport_pc_probe_port() doesn't
> initialize the dma_mask and coherent_dma_mask of the device and calls
> dma_alloc_coherent with it. dma_alloc_coherent fails because
> dma_alloc_coherent() doesn't accept the uninitialized dma_mask:
> 
> http://lkml.org/lkml/2009/6/16/150
> 
> Long ago, X86_32 and X86_64 had the own dma_alloc_coherent
> implementations; X86_32 accepted a device having dma_mask that is not
> initialized however X86_64 didn't. When we merged them, we chose to
> prohibit a device having dma_mask that is not initialized. I think
> that it's good to require drivers to set up dma_mask (and
> coherent_dma_mask) properly if the drivers want DMA.
> 
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> Reported-by: Malcom Blaney <malcolm.blaney@maptek.com.au>
> Tested-by: Malcom Blaney <malcolm.blaney@maptek.com.au>
> Cc: stable@kernel.org
> Signed-off-by: Alan Cox <alan@linux.intel.com>
> ---
> 
>  drivers/parport/parport_pc.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)

Acked-by: Jeff Garzik <jgarzik@redhat.com>