Re: [PATCH 2/4] libata: Clear tf before doing request sense

[Tejun Heo <htejun@gmail.com>]

Albert Lee wrote:
> diff -Nrup 01_hsm_st/drivers/ata/libata-eh.c 02_aopen_rs/drivers/ata/libata-eh.c
> --- 01_hsm_st/drivers/ata/libata-eh.c	2007-03-23 16:56:13.000000000 +0800
> +++ 02_aopen_rs/drivers/ata/libata-eh.c	2007-03-31 01:11:01.000000000 +0800
> @@ -991,18 +991,19 @@ static unsigned int atapi_eh_request_sen
>  
>  	DPRINTK("ATAPI request sense\n");
>  
> -	ata_tf_init(dev, &tf);
> -
>  	/* FIXME: is this needed? */
>  	memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);
>  
> -	/* XXX: why tf_read here? */
> +	/* read error register to initialize sense_buf */
>  	ap->ops->tf_read(ap, &tf);
>  
>  	/* fill these in, for the case where they are -not- overwritten */
>  	sense_buf[0] = 0x70;
>  	sense_buf[2] = tf.feature >> 4;

Oh, now I see why it's there.  Thanks for spotting this.  We don't need 
tf_read here, you can simply use the value in qc->result_tf.feature for 
this purpose.

-- 
tejun