From: Tejun Heo <tj@kernel.org>
To: Viresh Kumar <viresh.nitj@gmail.com>
Cc: viresh kumar <viresh.kumar@st.com>,
"linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>,
Shiraz HASHIM <shiraz.hashim@st.com>,
Armando VISCONTI <armando.visconti@st.com>,
amitgoel <amit.goel@st.com>
Subject: Re: MWDMA Issue: sda: unknown partition table
Date: Sat, 22 Jan 2011 12:45:59 +0100 [thread overview]
Message-ID: <20110122114559.GA6160@htj.dyndns.org> (raw)
In-Reply-To: <AANLkTimD0oDCx=UTYsenTNPgO4RgHGCKxrNyQ2u7atmE@mail.gmail.com>
Hello,
On Sat, Jan 22, 2011 at 09:38:46AM +0530, Viresh Kumar wrote:
> As soon as handshaking is done, a read request of 4096 bytes is given:
> Here in both cases (PIO and MWDMA) first block of 512 bytes contained
> non-zero data but the other 7 blocks contained 0.
Hmmm, okay. Well, I'm afraid you'll have to find out where things are
going wrong. fs/partitions/check.h::read_part_sector() is the read
function used by partition check code. You'll have to find where the
difference between what that code and your drive sees comes from.
Playing with dd in userland on the device node and see how reads and
writes behave would be helpful too.
> Also Arasan Controller, as far i have understood, doesn't transfer data directly
> to a memory location. Instead we need to read data from Controllers FIFO.
> So, probably it wouldn't be cache issue, as ARM is reading data directly from
> FIFO to our buffer (using its virtual address).
I don't really follow. It's DMA. The controller is writing to
memory.
Thanks.
--
tejun
next prev parent reply other threads:[~2011-01-22 11:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-21 10:09 MWDMA Issue: sda: unknown partition table viresh kumar
2011-01-21 10:14 ` Tejun Heo
2011-01-21 10:28 ` viresh kumar
2011-01-21 11:59 ` viresh kumar
2011-01-21 16:39 ` Tejun Heo
2011-01-22 4:08 ` Viresh Kumar
2011-01-22 11:45 ` Tejun Heo [this message]
2011-01-24 11:20 ` viresh kumar
2011-02-01 15:32 ` Viresh Kumar
2011-02-01 17:59 ` Eric D. Mudama
2011-02-02 3:43 ` viresh kumar
2011-02-02 5:55 ` Eric D. Mudama
2011-02-02 5:58 ` 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=20110122114559.GA6160@htj.dyndns.org \
--to=tj@kernel.org \
--cc=amit.goel@st.com \
--cc=armando.visconti@st.com \
--cc=linux-ide@vger.kernel.org \
--cc=shiraz.hashim@st.com \
--cc=viresh.kumar@st.com \
--cc=viresh.nitj@gmail.com \
/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).