From: Tejun Heo <tj@kernel.org>
To: Huang Changming-R66093 <r66093@freescale.com>
Cc: "linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>
Subject: Re: [PATCH] libata-pmp: add schedule timeout to support some PMP cards
Date: Thu, 10 Nov 2011 07:20:36 -0800 [thread overview]
Message-ID: <20111110152036.GB27258@google.com> (raw)
In-Reply-To: <8A2FC72B45BB5A4C9F801431E06AE48F11617501@039-SN1MPN1-005.039d.mgd.msft.net>
Hello,
On Thu, Nov 10, 2011 at 08:07:47AM +0000, Huang Changming-R66093 wrote:
> > Ummm... We can't really issue commands after failure without going
> > through recovery. For ahci, it probably works. For other controllers,
> > it may not. Where does this delay come from? Is there any other way
> > to wait for device readiness?
> >
> It is very bad. I have two PMP cards, one (5 ports) can work well
> without the delay time before reading PMP SCR, but the other (15
> ports) must delay enough time before reading the PMP SCR. It seems
> there is no other way to detect the device readiness.
>
> Maybe I will just delay some time before send SCR command, if it
> failed, then we will report this error to driver?
Hmmm... I'm curious what's causing the problem. Which port multiplier
are we talking about? If it's specific to that PMP, we can add quirk
to support it. Does the problem also happen when the PMP is connected
to a different controller?
Thanks.
--
tejun
next prev parent reply other threads:[~2011-11-10 15:20 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-31 3:57 [PATCH] libata-pmp: add schedule timeout to support some PMP cards r66093
2011-11-03 16:07 ` Tejun Heo
2011-11-10 8:07 ` Huang Changming-R66093
2011-11-10 15:20 ` Tejun Heo [this message]
2011-11-15 8:43 ` Huang Changming-R66093
2011-11-15 14:51 ` Tejun Heo
2011-11-15 15:24 ` Mark Lord
2011-11-15 16:04 ` Mark Lord
2011-11-16 9:00 ` Huang Changming-R66093
2011-11-16 14:20 ` Mark Lord
2011-12-16 10:58 ` Huang Changming-R66093
2011-12-16 11:00 ` Huang Changming-R66093
2011-12-16 11:10 ` Huang Changming-R66093
2011-11-16 9:13 ` Huang Changming-R66093
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