Re: [PATCH] [SCSI] LIBSAS: fix libsas link error issue

James Bottomley
2011-06-14T15:29:32Z

On Tue, 2011-06-14 at 23:17 +0800, yxlraid@gmail.com wrote:
> From: Xiangliang Yu <yuxiangl@marvell.com>
>
> -- The value of child link rate should is minimum of link rate, or
> command will fail if child link rate is bigger than parent link rate.
>
> Signed-off-by: Xiangliang Yu <yuxiangl@marvell.com>
> ---
> drivers/scsi/libsas/sas_expander.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
> index 874e29d..6ccca09 100644
> --- a/drivers/scsi/libsas/sas_expander.c
> +++ b/drivers/scsi/libsas/sas_expander.c
> @@ -638,7 +638,7 @@ static void sas_ex_get_linkrate(struct domain_device *parent,
> sas_port_add_phy(port, phy->phy);
> }
> }
> - child->linkrate = min(parent_phy->linkrate, child->max_linkrate);
> + child->linkrate = min(parent_phy->linkrate, child->min_linkrate);

This patch doesn't look right. It will clamp the phy to the minimum
possible link rate. The child is supposed to support everywhere between
child->min_linkrate and child->max_linkrate. The reason why we pick the
max is because we should use that if the parent supports it, and fall
back only if the parent isn't capable.

James