linux-ide.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Tejun Heo <htejun@gmail.com>
To: Jeff Garzik <jeff@garzik.org>, Mark Lord <liml@rtr.ca>,
	Alan Cox <alan@lxorguk.ukuu.org.uk>,
	IDE/ATA development list <linux-ide@vger.kernel.org>,
	andre@linux-ide.org, Bartlomiej
Subject: Re: [CALL-FOR-HELP] pata_ali: can't get MWDMA working!
Date: Thu, 10 Jan 2008 02:01:48 +0900	[thread overview]
Message-ID: <4784FDFC.7050908@gmail.com> (raw)
In-Reply-To: <4784FBC1.7070804@gmail.com>

Oh... I forgot to mention something.

I traced DMA command execution and the following is what happens.

1. host setups DMA engine (programs BMDMA controller)
2. host issues PACKET
3. device sets BSY
4. host transfers CDB when BSY clears and DRQ sets (Status turns to 0xd0)
5. host activates BMDMA engine
6. device reports 0xd0 for all TF regs for short moment and then it
   clears BSY and sets DRQ and other regs.
7. nothing happens for quite long time (>10s)
8. after a while, device seems to give up and clears DRQ and sets
   DRDY.
9. BMDMA status is 0x21 and doesn't change.
10. after a while, timeout occurrs.

I cleared the buffer before issuing commnad and checked whether DMA
engine delievered anything from EH.  It transfered nothing.  It looks
like for some reason the BMDMA engine is losing its chance to start.

Thanks.

-- 
tejun

  reply	other threads:[~2008-01-09 17:01 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-09 16:52 [CALL-FOR-HELP] pata_ali: can't get MWDMA working! Tejun Heo
2008-01-09 17:01 ` Tejun Heo [this message]
2008-01-09 17:16 ` Alan Cox
2008-01-09 17:28   ` Alan Cox
2008-01-10  1:44   ` Tejun Heo
2008-01-09 17:25 ` Mark Lord
2008-01-10  1:49   ` Tejun Heo
2008-01-09 17:27 ` Sergei Shtylyov
2008-01-10  2:14   ` Tejun Heo
2008-01-09 22:55 ` Bartlomiej Zolnierkiewicz
2008-01-10  1:39   ` Tejun Heo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4784FDFC.7050908@gmail.com \
    --to=htejun@gmail.com \
    --cc=alan@lxorguk.ukuu.org.uk \
    --cc=andre@linux-ide.org \
    --cc=jeff@garzik.org \
    --cc=liml@rtr.ca \
    --cc=linux-ide@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).