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From: Roland Dreier <rdreier@cisco.com>
To: benh@kernel.crashing.org
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>,
	Linux Kernel list <linux-kernel@vger.kernel.org>,
	linux-scsi <linux-scsi@vger.kernel.org>,
	Russell King <rmk@arm.linux.org.uk>
Subject: Re: SCSI breakage on non-cache coherent architectures
Date: Mon, 19 Nov 2007 13:43:59 -0800	[thread overview]
Message-ID: <adapry5ykps.fsf@cisco.com> (raw)
In-Reply-To: <1195450523.7022.37.camel@pasglop> (Benjamin Herrenschmidt's message of "Mon, 19 Nov 2007 16:35:23 +1100")

 > I've been debugging various issues on the PowerPC 44x embedded
 > architecture which happens to have non-coherent PCI DMA.
 > 
 > One of the problem I'm hitting is that one really need to enforce
 > kmalloc alignement to cache lines or bad things will happen (among
 > others with USB), for some reasons, powerpc failed to do so, I fixed it.

Heh... I hit the same problem literally 5 years ago:
    http://lwn.net/Articles/1783/

I implemented the __dma_buffer annotation:
    http://lwn.net/Articles/2269/

But DaveM said we should just use the PCI pool code instead:
    http://lwn.net/Articles/2270/

 - R.

  parent reply	other threads:[~2007-11-19 21:44 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-19  5:35 SCSI breakage on non-cache coherent architectures Benjamin Herrenschmidt
2007-11-19  8:38 ` David Miller
2007-11-19 19:51   ` Benjamin Herrenschmidt
2007-11-19 22:31     ` David Miller
2007-11-20  0:34       ` Benjamin Herrenschmidt
2007-11-20  0:46         ` David Miller
2007-11-20  0:55           ` Benjamin Herrenschmidt
2007-11-20  0:57             ` David Miller
2007-11-20  2:10           ` Roland Dreier
2007-11-20  2:35             ` Benjamin Herrenschmidt
2007-11-20  3:14             ` Benjamin Herrenschmidt
2007-11-20 19:35               ` James Bottomley
2007-11-20  8:29     ` Thomas Bogendoerfer
2007-11-20 14:36       ` James Bottomley
2007-11-20 20:05         ` Roland Dreier
2007-11-20 21:10           ` James Bottomley
2007-11-20 22:39             ` Benjamin Herrenschmidt
2007-11-20 23:09               ` James Bottomley
2007-11-19 12:32 ` Matthew Wilcox
2007-11-19 15:09   ` James Bottomley
2007-11-19 19:54     ` Benjamin Herrenschmidt
2007-11-19 19:55     ` Benjamin Herrenschmidt
2007-11-19 19:53   ` Benjamin Herrenschmidt
2007-11-19 21:43 ` Roland Dreier [this message]
2007-11-19 21:55   ` Benjamin Herrenschmidt

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