From: FUJITA Tomonori
Date: Tue Jun 16 2009 - 04:56:29 EST
On Tue, 16 Jun 2009 17:53:03 +0930
Malcom Blaney <malcolm.blaney@xxxxxxxxxxxxx> wrote:
> Hi Fujita,
> 2009/6/16 FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>:
> > You use X86_32, right?
> I have CONFIG_X86_32=y in my config file.
> > In 2.6.25, 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, I think.
> > When we merged them, we chose to prohibit a device having dma_mask
> > that is not initialized. I'm not sure the DMA docs say this but IMO
> > it's good to require drivers to set up dma_mask (and
> > coherent_dma_mask) properly if the drivers want DMA.
> If you could point me in the direction of how to set these values
> correctly, I would appreciate it.
You hit the problem that a device that parport_pc_probe_port creates
but doesn't set up the dma_mask properly, right (I'm not familiar with
the driver at all so I might misunderstand something)?
If so, I guess that the following patch works (only compile tested).
diff --git a/drivers/parport/parport_pc.c b/drivers/parport/parport_pc.c
index 151bf5b..1af57b7 100644
@@ -2271,6 +2271,9 @@ struct parport *parport_pc_probe_port(unsigned long int base,
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);
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/