Re: [PATCH v2 00/17] net: introduce Qualcomm IPA driver
From: Alex Elder
Date: Mon Jun 24 2019 - 12:22:01 EST
On 6/18/19 2:22 PM, Johannes Berg wrote:
> On Tue, 2019-06-18 at 09:00 -0500, Alex Elder wrote:
. . .
> Anyway, I think for now we could probably live with not having this
> configurable for the IPA driver, and if it *does* need to be
> configurable, it seems like it should be a driver configuration, not a
> channel configuration - so something like a debugfs hook if you really
> just need to play with it for performance testing, or a module
> parameter, or something else?
> Or even, in the WWAN framework, a knob that we provide there for the
> WWAN device, rather than for the (newly created) channel.
Agreed. I think a knob is appropriate, it's just a question of how
that control exposed. Same answer to your question below.
>> The hardware is capable of aggregating QMAP packets
>> arriving on a connection into a single buffer, so this provides
>> a way of requesting it do that.
>>>> #define RMNET_FLAGS_INGRESS_MAP_COMMANDS (1U << 1)
>>> Similar here? If you have flow control you probably want to use it?
>> I agree with that, though perhaps there are cases where it
>> is pointless, or can't be supported, so one might want to
>> simply *not* implement/advertise the feature. I don't know.
> Sure, but then that's likely something the driver would need to know,
> not necessarily userspace?