From: Mark Lord <liml@rtr.ca>
To: Robert Hancock <hancockrwd@gmail.com>
Cc: Philippe De Muyter <phdm@macqel.be>,
linux-ide@vger.kernel.org, davem@davemloft.net,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH ide] : Increase WAIT_DRQ to support slow CF cards
Date: Sat, 31 Oct 2009 09:56:26 -0400 [thread overview]
Message-ID: <4AEC420A.9030502@rtr.ca> (raw)
In-Reply-To: <4AE64031.5060105@gmail.com>
Robert Hancock wrote:
..
> This has come up before:
>
> http://marc.info/?l=linux-ide&m=123064513313466&w=2
>
> I think this timeout should not even exist. libata has no such timeout
> (only the overall command completion timeout), and I can't find any
> reference in current ATA specs to the device being required to raise DRQ
> in any particular amount of time.
..
The reason for the original (20ms, then 50ms) timeout was this text
from the ATA1 specification, long since outdated:
- Upon receipt of a Class 3 command, the drive sets BSY within 400 nsec,
sets up the sector buffer for a write operation, sets DRQ within 20
msec, and clears BSY within 400 nsec of setting DRQ.
Cheers
next prev parent reply other threads:[~2009-10-31 13:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-26 16:20 [PATCH ide] : Increase WAIT_DRQ to support slow CF cards Philippe De Muyter
2009-10-27 0:34 ` Robert Hancock
2009-10-27 0:45 ` David Miller
2009-10-27 1:07 ` Robert Hancock
2009-10-27 1:19 ` David Miller
2009-10-27 1:40 ` Robert Hancock
2009-10-27 1:43 ` David Miller
2009-10-27 9:45 ` Philippe De Muyter
2009-10-27 10:24 ` Sergei Shtylyov
2009-10-31 13:56 ` Mark Lord [this message]
2009-12-03 5:57 ` David Miller
2009-12-03 8:55 ` Philippe De Muyter
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