From: Dan Murphy <dmurphy@ti.com>
To: Mark Brown <broonie@kernel.org>
Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-omap@vger.kernel.org
Subject: Re: [PATCH] regmap: Allow read_reg_mask to be 0
Date: Tue, 30 Sep 2014 15:20:04 -0500 [thread overview]
Message-ID: <542B1074.5000802@ti.com> (raw)
In-Reply-To: <20140930172543.GG4273@sirena.org.uk>
On 09/30/2014 12:25 PM, Mark Brown wrote:
> On Tue, Sep 30, 2014 at 11:07:00AM -0500, Dan Murphy wrote:
>
>> - if (config->read_flag_mask || config->write_flag_mask) {
>> + if (config->read_flag_mask == REGMAP_NO_READ_MASK)
>> + map->read_flag_mask = 0x00;
>> + else if (config->read_flag_mask)
> This breaks the symmetry in handling of read and write masks which isn't
> great, please make the equivalent update for the write mask too.
Hmmm. If I make the similar change for the write mask I will be adding dead
code as write_flag_mask is not defaulted by the bus like the read_flag_mask which is
defaulted to 0x80 in the regmap-spi code. The i2c code does not make this assumption.
The original code did not seem to have symmetry as the only instance
that write_flag_mask is modified is if it is non-zero.
Let me know what you think. I can add the code to make it more symmetrical but
we may be adding code that is dead. If I remove the defaulted read_flag_mask value out
of the spi driver then I will need to find every spi device that needs that flag and set it.
IMHO that would be really messy and probably mess us some drivers.
>> +#define REGMAP_NO_READ_MASK 0xff
> An actual out of band value might be preferable here though that'd
> involve changing the type and more checking so perhaps inessential.
Thought about making this -1 with a variable change but that seemed
really drastic where a value of 0xff seems to be a value that no one should use.
Dan
--
------------------
Dan Murphy
WARNING: multiple messages have this Message-ID (diff)
From: Dan Murphy <dmurphy@ti.com>
To: Mark Brown <broonie@kernel.org>
Cc: <gregkh@linuxfoundation.org>, <linux-kernel@vger.kernel.org>,
<linux-omap@vger.kernel.org>
Subject: Re: [PATCH] regmap: Allow read_reg_mask to be 0
Date: Tue, 30 Sep 2014 15:20:04 -0500 [thread overview]
Message-ID: <542B1074.5000802@ti.com> (raw)
In-Reply-To: <20140930172543.GG4273@sirena.org.uk>
On 09/30/2014 12:25 PM, Mark Brown wrote:
> On Tue, Sep 30, 2014 at 11:07:00AM -0500, Dan Murphy wrote:
>
>> - if (config->read_flag_mask || config->write_flag_mask) {
>> + if (config->read_flag_mask == REGMAP_NO_READ_MASK)
>> + map->read_flag_mask = 0x00;
>> + else if (config->read_flag_mask)
> This breaks the symmetry in handling of read and write masks which isn't
> great, please make the equivalent update for the write mask too.
Hmmm. If I make the similar change for the write mask I will be adding dead
code as write_flag_mask is not defaulted by the bus like the read_flag_mask which is
defaulted to 0x80 in the regmap-spi code. The i2c code does not make this assumption.
The original code did not seem to have symmetry as the only instance
that write_flag_mask is modified is if it is non-zero.
Let me know what you think. I can add the code to make it more symmetrical but
we may be adding code that is dead. If I remove the defaulted read_flag_mask value out
of the spi driver then I will need to find every spi device that needs that flag and set it.
IMHO that would be really messy and probably mess us some drivers.
>> +#define REGMAP_NO_READ_MASK 0xff
> An actual out of band value might be preferable here though that'd
> involve changing the type and more checking so perhaps inessential.
Thought about making this -1 with a variable change but that seemed
really drastic where a value of 0xff seems to be a value that no one should use.
Dan
--
------------------
Dan Murphy
next prev parent reply other threads:[~2014-09-30 20:20 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-30 16:07 [PATCH] regmap: Allow read_reg_mask to be 0 Dan Murphy
2014-09-30 16:07 ` Dan Murphy
2014-09-30 17:25 ` Mark Brown
2014-09-30 20:19 ` Dan Murphy
2014-09-30 20:19 ` Dan Murphy
2014-09-30 20:20 ` Dan Murphy [this message]
2014-09-30 20:20 ` Dan Murphy
2014-09-30 20:39 ` Dan Murphy
2014-09-30 20:39 ` Dan Murphy
2014-09-30 21:03 ` Lars-Peter Clausen
2014-09-30 21:18 ` Dan Murphy
2014-09-30 21:18 ` Dan Murphy
2014-09-30 21:29 ` Lars-Peter Clausen
2014-10-01 11:15 ` Mark Brown
2014-10-01 11:39 ` Dan Murphy
2014-10-01 11:39 ` Dan Murphy
2014-10-01 16:30 ` Lars-Peter Clausen
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