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From: Hannes Reinecke <hare@suse.de>
To: James Bottomley <James.Bottomley@SteelEye.com>
Cc: SCSI Mailing List <linux-scsi@vger.kernel.org>
Subject: Fallback sequence in scsi_transport_spi
Date: Mon, 25 Jul 2005 10:30:31 +0200	[thread overview]
Message-ID: <42E4A327.90005@suse.de> (raw)

Hi James,

it appears that the fallback sequence in
scsi_transport_spi.c:spi_dv_retrain()
is somewhat incorrect.

According to SPI-3 (spi3r14, actually), the flags DT, IU, and QAS can be
set in the following order of precedence (Table 55, p 155):
- DT
- IU
- QAS

This implies that for QAS DT and IU _have_ to be set. Vice versa for a
retrain we first should unset QAS, then IU (as QAS without IU is
invalid) and then DT.

However, the fallback routine in spi_dv_retrain first unsets IU, _then_
QAS, and ignoring DT entirely. This smells a bit fishy.
Any reasons for this?

Cheers,

Hannes
-- 
Dr. Hannes Reinecke			hare@suse.de
SuSE Linux Products GmbH		S390 & zSeries
Maxfeldstraße 5				+49 911 74053 688
90409 Nürnberg				http://www.suse.de

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             reply	other threads:[~2005-07-25  8:30 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-07-25  8:30 Hannes Reinecke [this message]
2005-07-25 12:19 ` Fallback sequence in scsi_transport_spi James Bottomley

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