From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Scott Wood <scottwood@freescale.com>
Cc: Xie Shaohui-B21989 <B21989@freescale.com>,
Zang Roy-R61911 <r61911@freescale.com>,
Timur Tabi <timur@tabi.org>,
"tiejun.chen" <tiejun.chen@windriver.com>,
Fleming Andy-AFLEMING <afleming@freescale.com>,
Bhushan Bharat-R65777 <R65777@freescale.com>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: FSL 64-bit DMA window question
Date: Sat, 08 Jun 2013 08:39:53 +1000 [thread overview]
Message-ID: <1370644793.3766.423.camel@pasglop> (raw)
In-Reply-To: <1370644475.6813.17@snotra>
On Fri, 2013-06-07 at 17:34 -0500, Scott Wood wrote:
> > You also need to account for other on-chip MMIOs no ? Or do you never
> > intend to let PCI devices hit them ?
>
> I don't think we normally need that (other than MSIs, which have a
> special window under 4G)... The question is whether it's better to let
> odd use cases work without having to manually move the DMA window, at
> the cost of decreased out-of-the-box performance with common PCIe cards.
Sorry, I didn't parse what the tradeoff is here...
Putting the inbound window above memory seems like a reasonable option then
(at least as a default that the board can override).
I sincerely hope those radeons are the only remaining things with that sort of
limitation but you never know ... it's all x86 fault of course for never having
used high DMA windows :-)
Cheers,
Ben.
next prev parent reply other threads:[~2013-06-07 22:40 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-16 4:47 SATA FSL and upstreaming Benjamin Herrenschmidt
2013-05-16 5:45 ` Benjamin Herrenschmidt
2013-05-16 5:55 ` tiejun.chen
2013-05-16 6:06 ` Benjamin Herrenschmidt
2013-05-16 5:59 ` Zang Roy-R61911
2013-05-16 6:01 ` Bhushan Bharat-R65777
2013-05-16 6:05 ` Zang Roy-R61911
2013-05-16 6:09 ` Benjamin Herrenschmidt
2013-05-16 6:17 ` tiejun.chen
2013-05-16 6:20 ` Zang Roy-R61911
2013-05-16 6:25 ` tiejun.chen
2013-05-16 7:20 ` Zang Roy-R61911
2013-05-16 6:26 ` Benjamin Herrenschmidt
2013-05-16 6:21 ` Benjamin Herrenschmidt
2013-05-16 6:35 ` tiejun.chen
2013-05-16 6:37 ` Zang Roy-R61911
2013-05-16 6:40 ` Benjamin Herrenschmidt
2013-05-16 6:43 ` tiejun.chen
2013-05-16 6:48 ` Bhushan Bharat-R65777
2013-05-16 6:49 ` Zang Roy-R61911
2013-05-16 6:53 ` Benjamin Herrenschmidt
2013-05-16 6:56 ` tiejun.chen
2013-05-16 7:01 ` Zang Roy-R61911
2013-05-16 7:05 ` Benjamin Herrenschmidt
2013-05-16 7:13 ` Bhushan Bharat-R65777
2013-05-16 7:26 ` Benjamin Herrenschmidt
2013-05-16 7:20 ` Xie Shaohui-B21989
2013-05-16 7:25 ` Bhushan Bharat-R65777
2013-05-16 6:59 ` Benjamin Herrenschmidt
2013-05-16 7:17 ` Zang Roy-R61911
2013-05-16 6:52 ` Benjamin Herrenschmidt
2013-05-16 14:56 ` Timur Tabi
2013-06-07 3:52 ` Benjamin Herrenschmidt
2013-06-07 4:39 ` Benjamin Herrenschmidt
2013-06-07 4:45 ` Zang Roy-R61911
2013-06-07 4:47 ` Benjamin Herrenschmidt
2013-06-07 4:50 ` Zang Roy-R61911
2013-06-07 7:41 ` fsqrt Benjamin Herrenschmidt
2013-06-07 7:45 ` fsqrt Zang Roy-R61911
2013-06-07 8:53 ` fsqrt Benjamin Herrenschmidt
2013-06-07 8:59 ` fsqrt Benjamin Herrenschmidt
2013-06-07 10:48 ` fsqrt David Laight
2013-06-07 12:14 ` fsqrt Benjamin Herrenschmidt
2013-06-07 19:19 ` fsqrt Kumar Gala
2013-06-07 23:23 ` fsqrt Benjamin Herrenschmidt
2013-06-07 23:25 ` fsqrt Benjamin Herrenschmidt
2013-06-07 23:30 ` fsqrt Benjamin Herrenschmidt
2013-06-08 0:20 ` fsqrt Dan Malek
2013-06-08 0:34 ` fsqrt Benjamin Herrenschmidt
2013-06-08 1:13 ` fsqrt Dan Malek
2013-06-08 4:31 ` fsqrt Benjamin Herrenschmidt
2013-06-09 6:32 ` fsqrt Benjamin Herrenschmidt
2013-06-07 7:46 ` fsqrt tiejun.chen
2013-06-07 8:53 ` fsqrt Benjamin Herrenschmidt
2013-06-07 9:02 ` fsqrt tiejun.chen
2013-06-07 12:07 ` fsqrt Benjamin Herrenschmidt
2013-06-07 7:05 ` FSL 64-bit DMA window question Benjamin Herrenschmidt
2013-06-07 7:58 ` Zang Roy-R61911
2013-06-07 8:55 ` Benjamin Herrenschmidt
2013-06-07 9:44 ` Zang Roy-R61911
2013-06-07 12:09 ` Benjamin Herrenschmidt
[not found] ` <1370642488.6813.15@snotra>
2013-06-07 22:02 ` Scott Wood
2013-06-07 22:09 ` Benjamin Herrenschmidt
2013-06-07 22:34 ` Scott Wood
2013-06-07 22:39 ` Benjamin Herrenschmidt [this message]
2013-06-07 23:29 ` Scott Wood
2013-06-07 23:33 ` Benjamin Herrenschmidt
2013-06-07 12:09 ` SATA FSL and upstreaming Timur Tabi
2013-05-16 6:17 ` Zang Roy-R61911
2013-05-16 6:23 ` Benjamin Herrenschmidt
2013-05-16 6:33 ` Bhushan Bharat-R65777
2013-05-16 6:34 ` Benjamin Herrenschmidt
2013-05-16 6:35 ` Zang Roy-R61911
2013-05-16 6:37 ` Benjamin Herrenschmidt
2013-05-16 6:41 ` tiejun.chen
2013-05-16 6:48 ` Zang Roy-R61911
2013-05-16 6:24 ` Xie Shaohui-B21989
2013-05-16 6:31 ` Benjamin Herrenschmidt
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