Re: [PATCH v2 00/17] net: introduce Qualcomm IPA driver

From: Alex Elder
Date: Wed Jun 26 2019 - 09:51:10 EST


On 6/24/19 11:40 AM, Arnd Bergmann wrote:
> On Mon, Jun 24, 2019 at 6:21 PM Alex Elder <elder@xxxxxxxxxx> wrote:
>> On 6/18/19 2:03 PM, Johannes Berg wrote:
>>
>>> Really there are two possible ways (and they intersect to some extent).

. . .

>>> The other is something like IPA or the Intel modem driver, where the
>>> device is actually a single (e.g. PCIe) device and just has a single
>>> driver, but that single driver offers different channels.
>>
>> What I don't like about this is that it's more monolithic. It
>> seems better to have the low-level IPA or Intel modem driver (or
>> any other driver that can support communication between the AP
>> and WWAN device) present communication paths that other function-
>> specific drivers can attach to and use.
>
> I did not understand Johannes description as two competing models
> for the same code, but rather two kinds of existing hardware that
> a new driver system would have to deal with.

Based on my understanding of what he said in a message I just
responded to, I think you are exactly right.

. . .

> What we should try to avoid though is a way to add driver private
> interfaces that risk having multiple drivers create similar functionality
> in incompatible ways.

Agreed.

-Alex