Re: [PATCH libata-2.6] AHCI: compiler warning fix

[Jeff Garzik <jgarzik@pobox.com>]

Brett Russ wrote:
> This fixes the compile warning below, which seems due to the enum
> being signed:
> drivers/scsi/ahci.c:199: warning: overflow in implicit constant
> conversion
> 
> Signed-off-by: Brett Russ <russb@emc.com>
> 
> ===== drivers/scsi/ahci.c 1.17 vs edited =====
> --- 1.17/drivers/scsi/ahci.c	Thu Feb 24 14:52:41 2005
> +++ edited/drivers/scsi/ahci.c	Wed Mar  9 17:29:36 2005
> @@ -44,7 +44,6 @@
>  enum {
>  	AHCI_PCI_BAR		= 5,
>  	AHCI_MAX_SG		= 168, /* hardware max is 64K */
> -	AHCI_DMA_BOUNDARY	= 0xffffffff,
>  	AHCI_USE_CLUSTERING	= 0,
>  	AHCI_CMD_SLOT_SZ	= 32 * 32,
>  	AHCI_RX_FIS_SZ		= 256,
> @@ -135,6 +134,8 @@
>  	PORT_CMD_ICC_SLUMBER	= (0x6 << 28), /* Put i/f in slumber state */
>  };
>  
> +#define AHCI_DMA_BOUNDARY	0xffffffff

hmmmm, I think there's a better way to fix this.  A separate enum, and 
adding the suffix 'UL' to 0xffffffff should work, I would think.

In general, I try to avoid adding #defines of any nature.  It's just as 
efficient as an enum, and type/symbol information is available to the 
compiler and debugger when you use an enum.

	Jeff