From: haavard.skinnemoen@atmel.com (Haavard Skinnemoen)
To: linux-arm-kernel@lists.infradead.org
Subject: Query dw_dmac driver: All descriptors done, but channel not idle!
Date: Fri, 18 Jun 2010 15:52:34 +0200 [thread overview]
Message-ID: <20100618155234.1fc40ce7@hskinnemoen-d830> (raw)
In-Reply-To: <4C1B75B7.1080104@st.com>
Viresh KUMAR <viresh.kumar@st.com> wrote:
> Can somebody please confirm, if it a known issue or not? Or if there
> are some solutions for this problem.
I'm not aware of any such issue. The code was added as a purely
defensive thing; when writing it, I just thought about what might
happen if we go through all our descriptors without finding the current
one, and added some code to report the issue and try to recover.
I suppose it might be caused by some issue with the peripheral itself,
but I think it's more likely to be caused by some race condition in the
driver, i.e. something goes wrong when inserting or removing
descriptors in the chain.
What might be very good to know at this point is the value of
the llp variable, and perhaps also the value of the CH_EN register to
see if the channel is idle or not.
Haavard
next prev parent reply other threads:[~2010-06-18 13:52 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-18 13:33 Query dw_dmac driver: All descriptors done, but channel not idle! Viresh KUMAR
2010-06-18 13:52 ` Haavard Skinnemoen [this message]
2010-06-18 13:56 ` Viresh KUMAR
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=20100618155234.1fc40ce7@hskinnemoen-d830 \
--to=haavard.skinnemoen@atmel.com \
--cc=linux-arm-kernel@lists.infradead.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).