From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC] ARM: dma-mapping: outer cache is invalidated twice
Date: Tue, 15 Feb 2011 15:46:33 +0000 [thread overview]
Message-ID: <20110215154633.GN4152@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <AANLkTinpcYoHKKDhqy9mKpqOEGtMpNc1BSukNWH-GVBX@mail.gmail.com>
On Tue, Feb 15, 2011 at 04:11:09PM +0100, Per Forlin wrote:
> True. In my case write back is disable but read back is enable, that's
> why I didn't consider it.
What do you mean "write back is disable" ? You can only prevent
writebacks by using a write-through cache.
Any writeback cache, whether in read-allocate or read-write-allocate
mode will have writebacks.
> Do you think it is feasible to let dma-mapping detect the cache
> configurations in runtime in order to prevent "unnecessary" cache
> operations?
Let's first straighten out your cache understanding above, because I
don't think you understand properly yet.
next prev parent reply other threads:[~2011-02-15 15:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-15 13:14 [RFC] ARM: dma-mapping: outer cache is invalidated twice Per Forlin
2011-02-15 13:32 ` Russell King - ARM Linux
2011-02-15 13:41 ` Russell King - ARM Linux
2011-02-15 13:54 ` Per Forlin
2011-02-15 14:12 ` Russell King - ARM Linux
2011-02-15 15:11 ` Per Forlin
2011-02-15 15:46 ` Russell King - ARM Linux [this message]
2011-02-15 22:42 ` Per Forlin
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