Messages in this thread Patch in this message | | | From | Alan Cox <> | Subject | [PATCH 2/2] parport_pc: set properly the dma_mask for parport_pc device | Date | Mon, 22 Jun 2009 16:54:27 +0100 |
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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(-)
diff --git a/drivers/parport/parport_pc.c b/drivers/parport/parport_pc.c index 7f1cca7..1032d5f 100644 --- a/drivers/parport/parport_pc.c +++ b/drivers/parport/parport_pc.c @@ -2290,6 +2290,9 @@ struct parport *parport_pc_probe_port(unsigned long int base, if (IS_ERR(pdev)) return NULL; dev = &pdev->dev; + + dev->coherent_dma_mask = DMA_BIT_MASK(24); + dev->dma_mask = &dev->coherent_dma_mask; } ops = kmalloc(sizeof(struct parport_operations), GFP_KERNEL);
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