Re: [PATCH v2 0/6] UIO driver for APM X-Gene QMTM

From: Richard Weinberger
Date: Thu Oct 09 2014 - 08:23:15 EST


On Thu, Oct 9, 2014 at 2:17 PM, Ankit Jindal <ankit.jindal@xxxxxxxxxx> wrote:
> On 9 October 2014 17:36, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>> On Thursday 09 October 2014 14:14:33 Ankit Jindal wrote:
>>> On 30 September 2014 09:56, Ankit Jindal <ankit.jindal@xxxxxxxxxx> wrote:
>>> > This patchset enables user space access to APM X-Gene QMTM
>>> > using UIO framework.
>>> >
>>> > The patchset also introduces new type UIO_MEM_PHYS_CACHE
>>> > for mem regions because APM X-Gene QMTM device supports
>>> > cache coherency with CPU caches.
>>>
>>
>> I haven't been able to review the patch in detail yet, but I have
>> a very high-level question: how do you decide which driver to use?
>>
>> I understand that the normal use case is for the QMTM to be used by
>> the kernel directly rather than being exported to user space, and
>> that the network driver will just use it if it is there.
>
> This UIO driver will be disabled by default. When this driver is
> enabled, the other dependent drivers need to be removed from the
> config.

And if the user forgets or creates an allmod/yesconfig we have
undefined behavior?

--
Thanks,
//richard
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