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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Tue, 27 Mar 2018 09:48:23 +0200
Message-ID: <CAK8P3a2CD4nEDzMZxtn1QQJA3oQeX=-4v17AxhpTuUqk8boVhg@mail.gmail.com>
Subject: Re: [PATCH 17/19] csky: defconfig
To:     Guo Ren <ren_guo@c-sky.com>
Cc:     linux-arch <linux-arch@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Jason Cooper <jason@lakedaemon.net>,
        c-sky_gcc_upstream@c-sky.com, gnu-csky@mentor.com,
        thomas.petazzoni@bootlin.com, wbx@uclibc-ng.org
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On Tue, Mar 27, 2018 at 4:21 AM, Guo Ren <ren_guo@c-sky.com> wrote:
> On Mon, Mar 26, 2018 at 03:16:31PM +0200, Arnd Bergmann wrote:

>> > +CONFIG_CFG80211=y
>> > +CONFIG_CFG80211_DEBUGFS=y
>> > +CONFIG_CFG80211_WEXT=y
>>
>> I would guess you want IPV6 but not WEXT here.
> Gx6605s devlepment board support usb-wifi.
> Perhaps WEXT is needed by iwconfig or iwlist? So I just enable it.
> However, I'll consider to remove it.

I think it's only for backwards compatibility with old versions of
those tools. There are some older drivers that use WEXT as the
native interface, but CFG80211 based drivers have a netlink
interface.

>> > +CONFIG_FB=y
>> > +CONFIG_FB_TILEBLITTING=y
>> > +CONFIG_FB_SIMPLE=y
>> > +CONFIG_BACKLIGHT_LCD_SUPPORT=y
>> > +# CONFIG_LCD_CLASS_DEVICE is not set
>> > +# CONFIG_BACKLIGHT_CLASS_DEVICE is not set
>> > +# CONFIG_VGA_CONSOLE is not set
>> > +CONFIG_FRAMEBUFFER_CONSOLE=y
>> > +CONFIG_FRAMEBUFFER_CONSOLE_DETECT_PRIMARY=y
>> > +CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y
>> > +CONFIG_LOGO=y
>> > +# CONFIG_LOGO_LINUX_MONO is not set
>> > +# CONFIG_LOGO_LINUX_VGA16 is not set
>>
>> For new platforms, using the DRM subsystem is the recommend
>> way to do graphics, it mostly replaces the framebuffer subsystem
>> here.
> These used by:
> https://github.com/c-sky/addons-linux/tree/master/addons/drivers/video/fbdev/nationalchip
>
> I'll consider the DRM subsystem.

It used to be rather hard to write a new DRM driver, but that has
improved a lot recently. You might be able to fit your driver into
drivers/gpu/drm/tinydrm/, or maybe do something a bit more complex
like drivers/gpu/drm/pl111/ or drivers/gpu/drm/stm/.

       Arnd