Re: [PATCH] PNP: set the pnp_card dma_mask for use by ISAPnP cards

[Takashi Iwai]

At Sat, 31 May 2008 01:54:10 +0200,
Rene Herman wrote:
> 
> >From 801c13fb3e8564221a1fb21892dbe13add3d7cea Mon Sep 17 00:00:00 2001
> From: Rene Herman <rene.herman@xxxxxxxxx>
> Date: Fri, 30 May 2008 23:10:23 +0200
> Subject: [PATCH] PNP: set the pnp_card dma_mask for use by ISAPnP cards.
> 
> 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@xxxxxxxxx>
> Acked-by: Bjorn Helgaas <bjorn.helgaas@xxxxxx>
> Cc: Takashi Iwai <tiwai@xxxxxxx>

Acked-by: Takashi Iwai <tiwai@xxxxxxx>


thanks,

Takashi

> Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
> ---
>  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);
> -- 
> 1.5.2.2
> 
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