Re: [PATCH] staging: Add rtl8821ce PCIe WiFi driver

[Larry Finger]

On 5/15/19 8:06 AM, Kai-Heng Feng wrote:
> at 20:33, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> > On Wed, May 15, 2019 at 07:54:58PM +0800, Kai-Heng Feng wrote:
> > > at 19:40, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> > >
> > > > On Wed, May 15, 2019 at 07:24:01PM +0800, Kai-Heng Feng wrote:
> > > > > The rtl8821ce can be found on many HP and Lenovo laptops.
> > > > > Users have been using out-of-tree module for a while,
> > > > >
> > > > > The new Realtek WiFi driver, rtw88, will support rtl8821ce in 2020 or
> > > > > later.
> > > >
> > > > Where is that driver, and why is it going to take so long to get merged?
> > >
> > > rtw88 is in 5.2 now, but it doesnât support 8821ce yet.
> > >
> > > They plan to add the support in 2020.
> >
> > Who is "they" and what is needed to support this device and why wait a
> > full year?
>
> âTheyâ refers to Realtek.
> Itâs their plan so I canât really answer that on behalf of Realtek.
>
> > > > > 296 files changed, 206166 insertions(+)
> > > >
> > > > Ugh, why do we keep having to add the whole mess for every single one of
> > > > these devices?
> > >
> > > Because Realtek devices are unfortunately ubiquitous so the support is
> > > better come from kernel.
> >
> > That's not the issue here. The issue is that we keep adding the same
> > huge driver files to the kernel tree, over and over, with no real change
> > at all. We have seen almost all of these files in other realtek
> > drivers, right?
>
> Yes. They use one single driver to support different SoCs, different 
> architectures and even different OSes.
> Thatâs why itâs a mess.
>
> > Why not use the ones we already have?
>
> Itâs virtually impossible because Realtekâs mega wifi driver uses tons of 
> #ifdefs, only one chip can be selected to be supported at compile time.
>
> > But better yet, why not add proper support for this hardware and not use
> > a staging driver?
>
> Realtek plans to add the support in 2020, if everything goes well.
> Meanwhile, many users of HP and Lenovo laptops are using out-of-tree driver, 
> some of them are stuck to older kernels because they donât know how to fix the 
> driver. So I strongly think having this in kernel is beneficial to many users, 
> even itâs only for a year.

Why not solve the older kernel problem the way I do with drivers for many 
Realtek devices by creating a GitHub project with the kernel API changes 
properly handled by ifdef statements? See the lwfinger projects. That solves the 
problem of users without the skills needed to adjust to kernel changes without 
burdening the entire Linux kernel with these bloated drivers. There are no 
reasons that a wifi driver should require 200K lines of code!

Larry