Re: [PATCH 5/6] tty: serial: Add linflexuart driver for S32V234 - Stefan-gabriel Mirea

From: Stefan-gabriel Mirea <stefan-gabriel.mirea@nxp.com>
To: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "corbet@lwn.net" <corbet@lwn.net>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"mark.rutland@arm.com" <mark.rutland@arm.com>,
	"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
	"will@kernel.org" <will@kernel.org>,
	"shawnguo@kernel.org" <shawnguo@kernel.org>,
	Leo Li <leoyang.li@nxp.com>, "jslaby@suse.com" <jslaby@suse.com>,
	"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	Cosmin Stefan Stoica <cosmin.stoica@nxp.com>,
	Larisa Ileana Grigore <larisa.grigore@nxp.com>
Subject: Re: [PATCH 5/6] tty: serial: Add linflexuart driver for S32V234
Date: Wed, 7 Aug 2019 17:05:43 +0000	[thread overview]
Message-ID: <VI1PR0402MB2863C28FAB5DA6356280432BDFD40@VI1PR0402MB2863.eurprd04.prod.outlook.com> (raw)
In-Reply-To: 20190807165646.GA6584@kroah.com

On 8/7/2019 7:56 PM, gregkh@linuxfoundation.org wrote:
> On Wed, Aug 07, 2019 at 04:42:17PM +0000, Stefan-gabriel Mirea wrote:
>> On 8/6/2019 9:40 PM, gregkh@linuxfoundation.org wrote:
>>> On Tue, Aug 06, 2019 at 05:11:17PM +0000, Stefan-gabriel Mirea wrote:

<snip>

>>>> Other than that, I do not see anything wrong with the addition of a
>>>> define in serial_core.h for this purpose (which is also what most of the
>>>> serial drivers do, including amba-pl011.c, mentioned in
>>>> Documentation/driver-api/serial/driver.rst as providing the reference
>>>> implementation), so please be more specific.
>>>
>>> I am getting tired of dealing with merge issues with that list, and no
>>> one seems to be able to find where they are really needed for userspace,
>>> especially for new devices.  What happens if you do not have use it?
>>
>> I see. If I drop its usage completely and leave 'type' from the
>> uart_port as 0, uart_port_startup() will fail when finding that
>> uport->type == PORT_UNKNOWN at [1] (there may be other effects as well,
>> e.g. due to the check in uart_configure_port[2]).
>>
>> So I suppose that I need to define some nonzero 'PORT_KNOWN' macro in
>> the driver and use that one internally for 'type'. Is my understanding
>> correct? Will there be any problems if I define it to a positive integer
>> which is already assigned to another driver, according to serial_core.h?
> 
> Ugh, ok, that's messy, nevermind.  Keep the #define in there, I will try
> to figure out how to move all of these at once sometime in the future...
> 
> sorry for the noise.

No problem, thank you for your time.

Regards,
Stefan