linux-kernel - RE: [PATCH] [SCSI] LIBSAS: fix libsas link error issue

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <F766E4F80769BD478052FB6533FA745D19FAE66A54@SC-VEXCH4.marvell.com>
Date:	Tue, 14 Jun 2011 21:52:05 -0700
From:	Xiangliang Yu <yuxiangl@...vell.com>
To:	"dgilbert@...erlog.com" <dgilbert@...erlog.com>
CC:	James Bottomley <James.Bottomley@...senPartnership.com>,
	"yxlraid@...il.com" <yxlraid@...il.com>,
	"jack_wang@...sh.com" <jack_wang@...sh.com>,
	"lucas.demarchi@...fusion.mobi" <lucas.demarchi@...fusion.mobi>,
	"maciej.trela@...el.com" <maciej.trela@...el.com>,
	"dan.j.williams@...el.com" <dan.j.williams@...el.com>,
	"linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Jacky Feng <jfeng@...vell.com>
Subject: RE: [PATCH] [SCSI] LIBSAS: fix libsas link error issue


On 11-06-14 09:44 PM, Xiangliang Yu wrote:
>> Subject: Re: [PATCH] [SCSI] LIBSAS: fix libsas link error issue
>>
>> On Tue, 2011-06-14 at 23:17 +0800, yxlraid@...il.com wrote:
>>>> From: Xiangliang Yu<yuxiangl@...vell.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@...vell.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 minim
>>> possible link rate.
>> Link negotiation should get the minimum.

>spl2r01.pdf [Most recent SAS-3 draft for the protocol layers]
>5.7.4.2.1 SAS speed negotiation sequence overview
>"The SAS speed negotiation sequence establishes communications between
>the two phys on a physical link at the highest possible transmission
>rate."
>That seems to suggest:
>    min(<one_end>.max_linkrate, <other_end>.max_linkrate)

Thanks！
The current statement like this: child->linkrate = min(child_phy_linkrate, max(parent->max_linkrate, child_phy_linkrate->max_linkrate);

How about this change:
child->linkrate = min(parent->max_linkrate, child->max_linkrate);