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Message-ID: <0f1095ef333da7ea103486a1121ca9038815e57c.camel@pengutronix.de>
Subject: Re: [PATCH v10 03/11] drm/etnaviv: Add dedicated functions to
 create and destroy platform device
From:   Lucas Stach <l.stach@pengutronix.de>
To:     Sui Jingfeng <suijingfeng@loongson.cn>,
        Sui Jingfeng <18949883232@163.com>,
        Russell King <linux+etnaviv@armlinux.org.uk>,
        Christian Gmeiner <christian.gmeiner@gmail.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>
Cc:     Bjorn Helgaas <bhelgaas@google.com>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        Philipp Zabel <p.zabel@pengutronix.de>,
        etnaviv@lists.freedesktop.org
Date:   Wed, 21 Jun 2023 16:00:38 +0200
In-Reply-To: <30d80802-2d9d-2816-1a02-240145f6dd3a@loongson.cn>
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         <0daa7182d6600a24988d1c81cf8fe3c0c9487f52.camel@pengutronix.de>
         <1c7596fd-7e63-6719-2574-7d7820687832@loongson.cn>
         <6d287bbb1733814009dfeb7d48f08cb6f44dc56c.camel@pengutronix.de>
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Am Mittwoch, dem 21.06.2023 um 21:31 +0800 schrieb Sui Jingfeng:
> On 2023/6/21 18:23, Lucas Stach wrote:
> > > While back to the question you ask, I want etnaviv_create_platform_device() to be generic,
> > > 
> > > can be used by multiple place for multiple purpose.
> > > 
> > > I have successfully copy this to a another drm driver by simply renaming.
> > > 
> > > The body of the function itself does not need to change.
> > But it isn't shared,
> 
> This can be shared for drm/etnaviv in the future,
> 
> currently, we just need an opportunity to use this function.
> 
I'm not convinced, yet.

> I want to create a dummy platform device,
> 
> let this dummy platform be bound to the single PCI GPU master.
> 
> 
> etnaviv_create_platform_device("dummy", &dummy_device);
> 
> 
> 1) To verify the component code path on PCI case.
> 
My favorite option would be to just always use the component path even
when the GPU is on a PCI device to keep both paths mostly aligned. One
could easily image both a 3D and a 2D core being made available though
the same PCI device.

> 2) Possibly for create a device for some other tiny hardware logic
> come with the platform
> 
Do you have something in mind here? Until now I assumed that only the
GPU core is behind the PCI abstraction. Is there something else sharing
the MMIO space?

Regards,
Lucas

> 3) Revival component_compare_dev_name() function.
> 
> > in this compilation unit this function is specific
> > to the etnaviv driver and I don't see why we shouldn't have etnaviv
> > specifics in there if it makes the code of this driver easier to
> > follow.
>