Re: [PATCH ide] : Increase WAIT_DRQ to support slow CF cards

[Philippe De Muyter <phdm@macqel.be>]

On Wed, Dec 02, 2009 at 09:57:38PM -0800, David Miller wrote:
> ide: Increase WAIT_DRQ to accomodate some CF cards and SSD drives.
> 
> Based upon a patch by Philippe De Muyter, and feedback from Mark
> Lord and Robert Hancock.
> 
> As noted by Mark Lord, the outdated ATA1 spec specifies a 20msec
> timeout for setting DRQ but lots of common devices overshoot this.
> 
> Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
> 
> diff --git a/include/linux/ide.h b/include/linux/ide.h
> index e4135d6..0ec6129 100644
> --- a/include/linux/ide.h
> +++ b/include/linux/ide.h
> @@ -125,8 +125,8 @@ struct ide_io_ports {
>   * Timeouts for various operations:
>   */
>  enum {
> -	/* spec allows up to 20ms */
> -	WAIT_DRQ	= HZ / 10,	/* 100ms */
> +	/* spec allows up to 20ms, but CF cards and SSD drives need more */
> +	WAIT_DRQ	= 1 * HZ,	/* 1s */
>  	/* some laptops are very slow */
>  	WAIT_READY	= 5 * HZ,	/* 5s */
>  	/* should be less than 3ms (?), if all ATAPI CD is closed at boot */