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From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eddie James <eajames@linux.vnet.ibm.com>,
	linux-i2c <linux-i2c@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	devicetree <devicetree@vger.kernel.org>,
	Wolfram Sang <wsa@the-dreams.de>,
	Rob Herring <robh+dt@kernel.org>, Joel Stanley <joel@jms.id.au>,
	Mark Rutland <mark.rutland@arm.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Randy Dunlap <rdunlap@infradead.org>
Subject: Re: [PATCH v9 2/7] i2c: Add FSI-attached I2C master algorithm
Date: Tue, 5 Jun 2018 12:17:48 +0300	[thread overview]
Message-ID: <CAHp75VeT1aN3Ek5-d2k11V_43gQWz2Yr1YTq__OoQnJzexFm2Q@mail.gmail.com> (raw)
In-Reply-To: <7daf29f643bb0445fceef85b1a7fff71048f2aa6.camel@kernel.crashing.org>

On Tue, Jun 5, 2018 at 2:38 AM, Benjamin Herrenschmidt
<benh@kernel.crashing.org> wrote:
> On Mon, 2018-06-04 at 22:21 +0300, Andy Shevchenko wrote:
>> > +#define I2C_INT_ENABLE         0x0000ff80
>> > +#define I2C_INT_ERR            0x0000fcc0
>>
>> Now it looks like a flags combinations.
>> For me as for reader would be better to see quickly a decoded line.
>>
>> My proposal is to introduce something like following
>>
>> _INT_ALL  GENMASK()
>> _INT_ENABLE (_INT_ALL & ~(_FOO | _BAR))
>> _INT_ERR ... similar way as above ...
>>
>> What do you think?
>
> I don't think this absolutely needs to change but yes, open coding is
> error prone. However I would think it more readable to use positive
> logic and just list all the bits that are *set* even if it's a bit more
> text:
>
> #define I2C_INT_ERR     (I2C_INT_INV_CMD        |\
>  I2C_INT_PARITY         |\
>                          I2C_INT_BE_OVERRUN     |\
>                         .../...)
>
> #define I2C_INT_ENABLE  (I2C_INT_ERR            |\
>                          I2C_INT_DAT_REQ        |\
>                          I2C_INT_CMD_COMP)

Yep, it's fine.
I prefered though slightly different style (not putting first value on
the same line with #define), but it doesn't matter.

>
> Note: Eddie, I notice I2C_INT_BUSY is in "ERR" but not in "ENABLE", any
> reason for that ?

Exactly the reason why I payid attention on these values.

-- 
With Best Regards,
Andy Shevchenko

  reply	other threads:[~2018-06-05  9:17 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-06-04 19:00 [PATCH v9 0/7] i2c: Add FSI-attached I2C master algorithm Eddie James
2018-06-04 19:00 ` [PATCH v9 1/7] dt-bindings: i2c: Add FSI-attached I2C master dt binding documentation Eddie James
2018-06-04 19:00 ` [PATCH v9 2/7] i2c: Add FSI-attached I2C master algorithm Eddie James
2018-06-04 19:21   ` Andy Shevchenko
2018-06-04 21:11     ` Eddie James
2018-06-04 23:38     ` Benjamin Herrenschmidt
2018-06-05  9:17       ` Andy Shevchenko [this message]
2018-06-05 13:31       ` Eddie James
2018-06-04 19:00 ` [PATCH v9 3/7] i2c: fsi: Add port structures Eddie James
2018-06-04 19:17   ` Andy Shevchenko
2018-06-04 19:40     ` Eddie James
2018-06-04 23:33     ` Benjamin Herrenschmidt
2018-06-04 19:00 ` [PATCH v9 4/7] i2c: fsi: Add abort and hardware reset procedures Eddie James
2018-06-04 19:00 ` [PATCH v9 5/7] i2c: fsi: Add transfer implementation Eddie James
2018-06-04 19:14   ` Andy Shevchenko
2018-06-04 19:37     ` Eddie James
2018-06-04 19:45   ` Peter Rosin
2018-06-04 21:12     ` Eddie James
2018-06-04 19:00 ` [PATCH v9 6/7] i2c: fsi: Add I2C master locking Eddie James
2018-06-04 19:00 ` [PATCH v9 7/7] i2c: fsi: Add bus recovery Eddie James
2018-06-04 19:22 ` [PATCH v9 0/7] i2c: Add FSI-attached I2C master algorithm Andy Shevchenko

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