Date:   Fri, 24 Dec 2021 09:59:13 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     hammer hsieh <hammerh0314@gmail.com>
Cc:     robh+dt@kernel.org, linux-serial@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        jirislaby@kernel.org, p.zabel@pengutronix.de, wells.lu@sunplus.com,
        Hammer Hsieh <hammer.hsieh@sunplus.com>
Subject: Re: [PATCH v5 2/2] serial:sunplus-uart:Add Sunplus SoC UART Driver
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On Fri, Dec 24, 2021 at 03:16:55PM +0800, hammer hsieh wrote:
> Hi, Greg KH :
> 
> In patch v1 coding quite mess, it is almost 2000 LOCs.
> For down size code under 1000 LOCs, I decide to drop DMA function code
> after patch v3.
> I think that's the biggest difference compared with 8250.
> Without DMA function, like you said it looks like 8250 variant.
> I think I should put DMA function back in next submit.

The 8250 driver handles DMA just fine today, why is your chip doing it
differently?  Are you sure it is a different chip?  Who created a new
uart chip these days?

> Another question for why I need PORT_SLUNPLUS ?
> I just check many other uart driver, almost all driver define their
> own PORT number.
> Actually, I didn't know about it.
> Maybe some device like bluetooth(use uart port) need autoconfig.
> Then it will call ioctl with TIOCSERCONFIG.
> I don't have tool for calling type/config/request/release/verify.

If you do not need it, and you can not test for it, please do not add
it.

thanks,

greg k-h