dma_alloc_coherent() on x86 currently takes a passed in NULL device pointer to mean that it should allocate an ISA compatible (24-bit) buffer which is a bit of a hack.
The ALSA ISA drivers are the main consumers of this but have a struct device in fact readily available.
For the PnP drivers, the specific pnp_dev->dev device pointer is not always available at the right time so for now we want to pass the pnp_card->dev instead which is always available. Set its dma_mask in preparation for doing so.
This does not fix a current bug -- 2.6.26-rc1 stumbled over the NULL hack in dma_alloc_coherent() but this has already been fixed in commit 4a367f3a9dbf2e7ffcee4702203479809236ee6e by Takashi Iwai.
Signed-off-by: Rene Herman rene.herman@gmail.com Acked-by: Bjorn Helgaas bjorn.helgaas@hp.com Cc: Takashi Iwai tiwai@suse.de Cc: Alan Cox alan@lxorguk.ukuu.org.uk --- drivers/pnp/card.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/drivers/pnp/card.c b/drivers/pnp/card.c index a762a41..b00ef10 100644 --- a/drivers/pnp/card.c +++ b/drivers/pnp/card.c @@ -8,6 +8,7 @@ #include <linux/ctype.h> #include <linux/slab.h> #include <linux/pnp.h> +#include <linux/dma-mapping.h> #include "base.h"
LIST_HEAD(pnp_cards); @@ -167,6 +168,9 @@ struct pnp_card *pnp_alloc_card(struct pnp_protocol *protocol, int id, char *pnp sprintf(card->dev.bus_id, "%02x:%02x", card->protocol->number, card->number);
+ card->dev.coherent_dma_mask = DMA_24BIT_MASK; + card->dev.dma_mask = &card->dev.coherent_dma_mask; + dev_id = pnp_add_card_id(card, pnpid); if (!dev_id) { kfree(card);