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From: Wolfram Sang <wsa@the-dreams.de>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] i2c: allow building emev2 without slave mode again
Date: Sun, 13 Dec 2015 09:09:59 +0000	[thread overview]
Message-ID: <20151213090959.GB1570@katana> (raw)
In-Reply-To: <2157023.1Ftpc9ZciN@wuerfel>

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> > > The slave_cb callback function is supposed to set the 'value'
> > > here,
> > 
> > Only if a master wants to READ from us.
> 
> Right, and can this never fail?

Exactly. The slave can stretch the clock if the value to be sent to the
master needs some processing first, but it must deliver something.

> With my current code to turn i2c_slave_event() into an empty inline function
> in case of !CONFIG_I2C_SLAVE, the compiler knows that "value" is uninitialized
> at the point where we write it to the register, and warns about it.

I overlooked that your first patch changed this code, sorry. Now I see
the problem.

What about not ifdeffing the inline function and keep the build error
whenever someone uses it without I2C_SLAVE being selected?

Thanks,

   Wolfram


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WARNING: multiple messages have this Message-ID (diff)
From: Wolfram Sang <wsa@the-dreams.de>
To: Arnd Bergmann <arnd@arndb.de>
Cc: "kbuild test robot" <lkp@intel.com>,
	kbuild-all@01.org, linux-i2c@vger.kernel.org,
	"Niklas Söderlund" <niklas.soderlund+renesas@ragnatech.se>,
	linux-sh@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i2c: allow building emev2 without slave mode again
Date: Sun, 13 Dec 2015 10:09:59 +0100	[thread overview]
Message-ID: <20151213090959.GB1570@katana> (raw)
In-Reply-To: <2157023.1Ftpc9ZciN@wuerfel>

[-- Attachment #1: Type: text/plain, Size: 800 bytes --]


> > > The slave_cb callback function is supposed to set the 'value'
> > > here,
> > 
> > Only if a master wants to READ from us.
> 
> Right, and can this never fail?

Exactly. The slave can stretch the clock if the value to be sent to the
master needs some processing first, but it must deliver something.

> With my current code to turn i2c_slave_event() into an empty inline function
> in case of !CONFIG_I2C_SLAVE, the compiler knows that "value" is uninitialized
> at the point where we write it to the register, and warns about it.

I overlooked that your first patch changed this code, sorry. Now I see
the problem.

What about not ifdeffing the inline function and keep the build error
whenever someone uses it without I2C_SLAVE being selected?

Thanks,

   Wolfram


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WARNING: multiple messages have this Message-ID (diff)
From: wsa@the-dreams.de (Wolfram Sang)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i2c: allow building emev2 without slave mode again
Date: Sun, 13 Dec 2015 10:09:59 +0100	[thread overview]
Message-ID: <20151213090959.GB1570@katana> (raw)
In-Reply-To: <2157023.1Ftpc9ZciN@wuerfel>


> > > The slave_cb callback function is supposed to set the 'value'
> > > here,
> > 
> > Only if a master wants to READ from us.
> 
> Right, and can this never fail?

Exactly. The slave can stretch the clock if the value to be sent to the
master needs some processing first, but it must deliver something.

> With my current code to turn i2c_slave_event() into an empty inline function
> in case of !CONFIG_I2C_SLAVE, the compiler knows that "value" is uninitialized
> at the point where we write it to the register, and warns about it.

I overlooked that your first patch changed this code, sorry. Now I see
the problem.

What about not ifdeffing the inline function and keep the build error
whenever someone uses it without I2C_SLAVE being selected?

Thanks,

   Wolfram

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  reply	other threads:[~2015-12-13  9:09 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-10 13:14 [PATCH] i2c: allow building emev2 without slave mode again Arnd Bergmann
2015-12-10 13:14 ` Arnd Bergmann
2015-12-10 13:14 ` Arnd Bergmann
2015-12-10 13:34 ` Wolfram Sang
2015-12-10 13:34   ` Wolfram Sang
2015-12-10 13:34   ` Wolfram Sang
2015-12-10 13:51   ` Arnd Bergmann
2015-12-10 13:51     ` Arnd Bergmann
2015-12-10 13:51     ` Arnd Bergmann
2015-12-10 13:51     ` Arnd Bergmann
2015-12-10 14:54 ` kbuild test robot
2015-12-10 14:54   ` kbuild test robot
2015-12-10 14:54   ` kbuild test robot
2015-12-10 15:06   ` Arnd Bergmann
2015-12-10 15:06     ` Arnd Bergmann
2015-12-10 15:06     ` Arnd Bergmann
2015-12-10 15:06     ` Arnd Bergmann
2015-12-10 15:17     ` Wolfram Sang
2015-12-10 15:17       ` Wolfram Sang
2015-12-10 15:17       ` Wolfram Sang
2015-12-12 16:20     ` Wolfram Sang
2015-12-12 16:20       ` Wolfram Sang
2015-12-12 16:20       ` Wolfram Sang
2015-12-12 21:05       ` Arnd Bergmann
2015-12-12 21:05         ` Arnd Bergmann
2015-12-12 21:05         ` Arnd Bergmann
2015-12-12 21:05         ` Arnd Bergmann
2015-12-13  9:09         ` Wolfram Sang [this message]
2015-12-13  9:09           ` Wolfram Sang
2015-12-13  9:09           ` Wolfram Sang
2015-12-14 12:02           ` Arnd Bergmann
2015-12-14 12:02             ` Arnd Bergmann
2015-12-14 12:02             ` Arnd Bergmann
2015-12-14 13:52             ` Wolfram Sang
2015-12-14 13:52               ` Wolfram Sang
2015-12-14 13:52               ` Wolfram Sang
2015-12-14 22:27               ` Arnd Bergmann
2015-12-14 22:27                 ` Arnd Bergmann
2015-12-14 22:27                 ` Arnd Bergmann
2015-12-17 12:01                 ` Wolfram Sang
2015-12-17 12:01                   ` Wolfram Sang
2015-12-17 12:01                   ` Wolfram Sang
2015-12-17 14:48                   ` Arnd Bergmann
2015-12-17 14:48                     ` Arnd Bergmann
2015-12-17 14:48                     ` Arnd Bergmann
2015-12-17 19:40                     ` Wolfram Sang
2015-12-17 19:40                       ` Wolfram Sang
2015-12-17 19:40                       ` Wolfram Sang
2015-12-17 19:57                       ` Arnd Bergmann
2015-12-17 19:57                         ` Arnd Bergmann
2015-12-17 19:57                         ` Arnd Bergmann
2015-12-17 19:57                         ` Arnd Bergmann

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