powerpc/dma: pci_set_dma_mask() shouldn't fail if mask fits in RAM

On an iMac G5, the b43 driver is failing to initialise because trying to
set the dma mask to 30-bit fails. Even though there's only 512MiB of RAM
in the machine anyway:
	https://bugzilla.redhat.com/show_bug.cgi?id=514787

We should probably let it succeed if the available RAM in the system
doesn't exceed the requested limit.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Benjamin Herrenschmidt 2009-08-10 16:36:38 +10:00
parent f4b9a98868
commit b2f2e8fee3

View file

@ -7,6 +7,7 @@
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/lmb.h>
#include <asm/bug.h>
#include <asm/abs_addr.h>
@ -90,11 +91,10 @@ static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
static int dma_direct_dma_supported(struct device *dev, u64 mask)
{
#ifdef CONFIG_PPC64
/* Could be improved to check for memory though it better be
* done via some global so platforms can set the limit in case
/* Could be improved so platforms can set the limit in case
* they have limited DMA windows
*/
return mask >= DMA_BIT_MASK(32);
return mask >= (lmb_end_of_DRAM() - 1);
#else
return 1;
#endif