From: Robert Hancock <hancockr@shaw.ca>
To: Mark Lord <liml@rtr.ca>
Cc: Alan Cox <alan@redhat.com>, Tejun Heo <htejun@gmail.com>,
Jeff Garzik <jgarzik@pobox.com>,
Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>,
ide <linux-ide@vger.kernel.org>
Subject: Re: PIO with SSDs: needs a long DRQ-after-command timeout for WRITEs
Date: Wed, 31 Dec 2008 11:33:06 -0600 [thread overview]
Message-ID: <495BACD2.6020500@shaw.ca> (raw)
In-Reply-To: <495B9D31.6080904@rtr.ca>
Mark Lord wrote:
> Robert Hancock wrote:
> ..
>> No idea about IDE, but libata does not wait at all for DRQ assertion
>> specifically, after issuing the PIO command it waits for BSY to be
>> deasserted and then expects either DRQ, DF or ERR to be set, else it's
>> a host state machine violation and triggers error handling. According
>> to the ATA spec, the device is specifically not allowed to set DRQ to
>> one while BSY is not asserted.
> ..
>
> Okay, so how long does it wait for BSY=0 under that same circumstance?
Just the overall command completion timeout, it would appear.. usually
30 seconds I believe.
IDE is really only waiting 50msec in this case? That seems rather
wrong.. I don't see anywhere in the current ATA specs that requires the
drive to respond within that time period.
next prev parent reply other threads:[~2008-12-31 17:33 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-30 13:53 PIO with SSDs: needs a long DRQ-after-command timeout for WRITEs Mark Lord
2008-12-30 13:59 ` Alan Cox
2008-12-31 16:29 ` Mark Lord
2008-12-31 18:38 ` Bartlomiej Zolnierkiewicz
2008-12-31 20:30 ` Mark Lord
2008-12-30 18:14 ` Robert Hancock
[not found] ` <495B9D31.6080904@rtr.ca>
2008-12-31 17:33 ` Robert Hancock [this message]
2008-12-31 18:03 ` Sergei Shtylyov
2008-12-31 18:06 ` Sergei Shtylyov
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