Re: [PATCH 4/5] ide: Add support for TRIM

[Mark Lord]

Matthew Wilcox wrote:
> From: David Woodhouse <David.Woodhouse@xxxxxxxxx>
>
> Signed-off-by: David Woodhouse <David.Woodhouse@xxxxxxxxx>
> [modified to reduce amount of special casing needed for discard]
> Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
> ---
..
> +	task->tf.command = ATA_CMD_DSM;
> +	task->tf.feature = ATA_DSM_TRIM;
> +	task->tf.hob_feature = 0x00;
> +	task->tf.nsect = size / 512;
> +	task->tf.hob_nsect = (size / 512) >> 8;
..

Matthew (or others),

Could you perhaps explain what the purpose of the data portion
of this command is for?  The draft ATA spec I have here has mangled
text in the description -- like it's missing a crucial sentence there.

So it's not obvious exactly why this command even needs data to
be transfered.

Thanks
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/