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Subject: Re: [PATCH v14 1/2] drm: add kms driver for loongson display
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To:     WANG Xuerui <kernel@xen0n.name>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Sui Jingfeng <suijingfeng@loongson.cn>,
        Li Yi <liyi@loongson.cn>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Christian Koenig <christian.koenig@amd.com>,
        Emil Velikov <emil.l.velikov@gmail.com>
Cc:     linaro-mm-sig@lists.linaro.org, loongson-kernel@lists.loongnix.cn,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Javier Martinez Canillas <javierm@redhat.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Liu Peibao <liupeibao@loongson.cn>, linux-media@vger.kernel.org
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Hi,

On 2023/5/21 20:21, WANG Xuerui wrote:
>> + * LS3A4000/LS3A5000/LS3A6000 CPU, they are equipped with on-board 
>> video RAM
>> + * typically. While LS2K0500/LS2K1000/LS2K2000 are low cost SoCs 
>> which share
>> + * the system RAM as video RAM, they don't has a dediacated VRAM.
>
> CPU models are not typically prefixed with "LS", so "Loongson 
> 3A4000/3A5000/3A6000".
>
Here is because when you do programming, variable name should prefix 
with letters.

> Also the description about the Loongson 2K series is a bit irrelevant 
> (we're focusing on VRAM here) so you could simplify the sentence a bit. 

We could reserve part of system RAM as VRAM for Loongson 2K series SoC.

Either reserved with 'of reserve memory' or  reserved by the firmware.

The reserve ram will not accessible by kernel itself it this case, and 
can still be managed by ttm.