From: Robert Jarzmik <robert.jarzmik@free.fr>
To: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>,
        David Woodhouse <dwmw2@infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] mtd: nand: pxa3xx_nand: add register access debug
References: <1439323034-8820-1-git-send-email-robert.jarzmik@free.fr>
	<20150818042426.GA27858@laptop>
Date: Tue, 18 Aug 2015 20:26:49 +0200
In-Reply-To: <20150818042426.GA27858@laptop> (Ezequiel Garcia's message of
	"Tue, 18 Aug 2015 01:24:26 -0300")
Message-ID: <874mjwa1w6.fsf@belgarion.home>
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Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> writes:

> On 11 Aug 09:57 PM, Robert Jarzmik wrote:
>> Add verbose debug for register accesses. This enables easier debugging
>> by following where and how hardware is stimulated, and how it answers.
>> 
>
> I really don't see why we want this patch. It's probably an useful hack to
> use in some cases, but can't see why we would want it in mainline.
>
> Feel free to prove me wrong.
Why not.

Imagine that there is a bug in the driver, such as the one with the status bits
clearing. You can't reproduce it, and the person who has the hardware to
reproduce it is not skilled enough to do any debug.

What are the tools and what will you ask this tester to do in order to debug and
solve his problem, as a good driver maintainer ?

Amongst the drivers I wrote in the past, this approach was the most reliable to
capture traces to debug remotely.

Cheers.

--
Robert
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