Re: [PATCH] pata_cmd640: don't read CFR pointlessly

[Jeff Garzik <jgarzik@pobox.com>]

On 05/08/2010 02:27 PM, Sergei Shtylyov wrote:
> cmd640_hardware_init() reads CFR but doesn't use the value read...
>
> Signed-off-by: Sergei Shtylyov<sshtylyov@ru.mvista.com>
>
> ---
> The patch is against the recent Linus' tree.
>
>   drivers/ata/pata_cmd640.c |    3 ---
>   1 file changed, 3 deletions(-)
>
> Index: linux-2.6/drivers/ata/pata_cmd640.c
> ===================================================================
> --- linux-2.6.orig/drivers/ata/pata_cmd640.c
> +++ linux-2.6/drivers/ata/pata_cmd640.c
> @@ -181,13 +181,10 @@ static struct ata_port_operations cmd640
>
>   static void cmd640_hardware_init(struct pci_dev *pdev)
>   {
> -	u8 r;
>   	u8 ctrl;
>
>   	/* CMD640 detected, commiserations */
>   	pci_write_config_byte(pdev, 0x5B, 0x00);
> -	/* Get version info */
> -	pci_read_config_byte(pdev, CFR,&r);
>   	/* PIO0 command cycles */

Agreed with this patch, but we lose some information:  all that remains 
is an uncommented 'CFR' definition.  Without the code comment, which is 
deleted in this patch, we have no idea what that register does.  Given 
that the chipset docs are not public AFAIK, this is a net loss of 
information about this chipset, IMO.

Maybe revise this patch, or add a second patch, which adds a comment 
where 'CFR' is defined?  Something as simple as "/* version info */" 
would be sufficient.

	Jeff