From: Eli Billauer <eli@billauer.co.il>
To: LKML <linux-kernel@vger.kernel.org>
Subject: Microblaze, DMA and cache: Lack of sync functions?
Date: Sat, 13 Aug 2011 13:12:00 +0300 [thread overview]
Message-ID: <4E464DF0.7030401@billauer.co.il> (raw)
Hello,
Before I make a needless hack, please correct me if I'm wrong: in
arch/microblaze/kernel/dma.c, the sync_single_for_cpu,
sync_single_for_device and friends are not set in the dma_direct_ops
structure (and not implemented), so calls from drivers to the
corresponding functions will do nothing. Since the Microblaze cache
doesn't update automatically on DMA operations, this looks like a bug to
me: The driver thinks the cache has been flushed or updated, but it
actually hasn't.
Map and unmap methods are indeed implemented and registered, and they
both call an internal function to sync the cache. So why are there no
sync functions?
To hack or not to hack?
Eli
--
Web: http://www.billauer.co.il
next reply other threads:[~2011-08-13 10:23 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-13 10:12 Eli Billauer [this message]
2011-08-15 12:22 ` Microblaze, DMA and cache: Lack of sync functions? Michal Simek
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=4E464DF0.7030401@billauer.co.il \
--to=eli@billauer.co.il \
--cc=linux-kernel@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