linux-kernel - Re: DMABOUNCE in pci-rcar

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: <20140320152640.GW7528@n2100.arm.linux.org.uk>
Date:	Thu, 20 Mar 2014 15:26:40 +0000
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	Ben Dooks <ben.dooks@...ethink.co.uk>
Cc:	Arnd Bergmann <arnd@...db.de>, linux-sh@...r.kernel.org,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Magnus Damm <damm@...nsource.se>,
	Ben Dooks <ben-linux@...ff.org>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Simon Horman <horms+renesas@...ge.net.au>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: DMABOUNCE in pci-rcar

On Thu, Mar 20, 2014 at 04:04:36PM +0100, Ben Dooks wrote:
> On 26/02/14 20:57, Arnd Bergmann wrote:
>> On Wednesday 26 February 2014 12:48:17 Bjorn Helgaas wrote:
>>> On Mon, Feb 24, 2014 at 4:00 AM, Arnd Bergmann <arnd@...db.de> wrote:
>>>> Hi Magnus,
>>>>
>>>> I noticed during randconfig testing that you enabled DMABOUNCE for the
>>>> pci-rcar-gen2 driver as posted in this patch https://lkml.org/lkml/2014/2/5/30
>>>>
>>>> I didn't see the original post unfortunately, but I fear we have to
>>>> revert it and come up with a better solution, ...
>>>
>>> Sounds like I should drop the following patches from my pci/host-rcar
>>> branch for now?
>>>
>>>    PCI: rcar: Add DMABOUNCE support
>>>    PCI: rcar: Enable BOUNCE in case of HIGHMEM
>>>    PCI: rcar: Make the Kconfig dependencies more generic
>>
>> Sounds good to me. The last patch is actually fine, but you'll have to
>> fix the context to apply it without the other two.
>
> As a note, if we now boot a Lager with DT on 3.14-rc3 series the USB
> controllers no longer work with full 2GiB RAM enabled in the device
> tree.
>
> Could we work around this by having 1GiB of memory defined in the
> 32bit memory and then add the rest of the 3GiB from the >32bit
> area via LPAE? Will the kernel ever try to allocate DMA memory from
> anything >32bit?

Ignore highmem.  What is the actual hardware restriction concerning memory
it can access?

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.
--
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/