linux-kernel - Re: [PATCH V3] pci: exynos: split into two parts such as Synopsys part and Exynos part

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <201309261151.42034.arnd@arndb.de>
Date:	Thu, 26 Sep 2013 11:51:41 +0200
From:	Arnd Bergmann <arnd@...db.de>
To:	Kishon Vijay Abraham I <kishon@...com>
Cc:	Pratyush Anand <pratyush.anand@...com>,
	Jingoo Han <jg1.han@...sung.com>,
	"'Bjorn Helgaas'" <bhelgaas@...gle.com>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
	"linux-samsung-soc@...r.kernel.org" 
	<linux-samsung-soc@...r.kernel.org>,
	"'Kukjin Kim'" <kgene.kim@...sung.com>,
	Mohit KUMAR DCG <Mohit.KUMAR@...com>,
	"'Sean Cross'" <xobs@...agi.com>,
	"'Thierry Reding'" <thierry.reding@...il.com>,
	"'SRIKANTH TUMKUR SHIVANAND'" <ts.srikanth@...sung.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>
Subject: Re: [PATCH V3] pci: exynos: split into two parts such as Synopsys part and Exynos part

On Thursday 26 September 2013, Kishon Vijay Abraham I wrote:
> On Wednesday 25 September 2013 02:53 AM, Arnd Bergmann wrote:
> > On Monday 23 September 2013, Kishon Vijay Abraham I wrote:
> >> Btw if we hadn't programmed inbound translation table, the address will go
> >> untranslated (according to the data book). I guess that's how it was working
> >> for Jingoo Han.
> >>
> >> **
> >> 3.10.4
> >> Inbound iATU Operation
> >>
> >> When there is no match, then the address is untranslated
> >> **
> >>
> > 
> > Well, that should work just as well, since you have a 1:1 translation anyway.
> > Do you get the same error without the translation?
> 
> Yes. I get the same non-fatal error interrupt in RC.

Ok, then I guess the translation is actually not at fault here but something
else. I would recommend looking at the IOMMU as the potential culprit. Maybe
having it disabled means that no DMA is going through, rather than all DMA
going through untranslated. Another possibility is that the IOMMU is set up
so that when disabled, it maps DMA address 0 to the start of RAM, rather
than identity mapping DMA address 0x80000000 there. If that's the case,
you either have to use the IOMMU, or set up the mapping in the root
complex to revert it.

	Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/