Re: [PATCH][RFC] PCI: rcar: Add bus notifier so we can limit the DMA range

[Marek Vasut <marek.vasut@gmail.com>]

On 05/22/2018 11:52 AM, Marek Vasut wrote:
> On 05/22/2018 10:10 AM, Arnd Bergmann wrote:
>> On Tue, May 22, 2018 at 12:05 AM, Marek Vasut <marek.vasut@gmail.com> wrote:
>>> From: Phil Edworthy <phil.edworthy@renesas.com>
>>>
>>> The PCIe DMA controller on RCar Gen2 and earlier is on 32bit bus,
>>> so limit the DMA range to 32bit.
>>>
>>> Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
>>> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
>>> Cc: Arnd Bergmann <arnd@arndb.de>
>>> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
>>> Cc: Phil Edworthy <phil.edworthy@renesas.com>
>>> Cc: Simon Horman <horms+renesas@verge.net.au>
>>> Cc: Wolfram Sang <wsa@the-dreams.de>
>>> Cc: linux-renesas-soc@vger.kernel.org
>>> To: linux-pci@vger.kernel.org
>>> ---
>>> NOTE: I'm aware of https://patchwork.kernel.org/patch/9495895/ , but the
>>>       discussion seems to have gone way off, so I'm sending this as a
>>>       RFC. Any feedback on how to do this limiting properly would be nice.
>>
>> Doing it in the driver is clearly not appropriate, we must do this in
>> common code. If I remember correctly, it's specifically ARM64 that is
>> broken here, it incorrectly allows setting a DMA mask to 64 bit
>> when that is not available.
> 
> Yep, that's correct. ARM64 with devices mapping tremendous amounts of
> memory. So did anything change since that discussion references in the NOTE?

Bump ? I think it'd be nice to sort this out once and for all, since I
doubt it's just this controller that has such a limitation.

-- 
Best regards,
Marek Vasut