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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "M. Warner Losh" <imp@bsdimp.com>
Cc: sfr@canb.auug.org.au, microblaze-uclinux@itee.uq.edu.au,
	devicetree-discuss@lists.ozlabs.org, jeremy.kerr@canonical.com,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 6/6] of/device: populate platform_device (of_device) resource table on allocation
Date: Fri, 11 Jun 2010 11:14:36 +1000	[thread overview]
Message-ID: <1276218876.1962.80.camel@pasglop> (raw)
In-Reply-To: <20100610.100140.8559628065321695.imp@bsdimp.com>

On Thu, 2010-06-10 at 10:01 -0600, M. Warner Losh wrote:
> : Oh, come on. Both constructions are binary equivalent.
> : 
> : So how can people seriously be with *that* code:
> : 
> :       dev->resource = (void *)&dev[1];
> : 
> : which, semantically, is a nonsense and asks for a fix.
> 
> It isn't nonsense.  That's just your opinion of it, nothing more.

No, it's dangerously fragile abuse of the C language which loses type
safety etc... It might be correct, but if somebody comes back in 2 year
to change something in that code, the chances of breaking it are higher
than having the type safe:

> :       dev_obj->dev.resource = dev_obj->resource;
> : 

Variant.

It's also less ugly.

> : simply makes sense.
> 
> But this requires extra, bogus fields in the structure and creates a
> bogus sizeof issue.
> 
> There are problems both ways.  Yelling about it isn't going to make
> you any more right, or convince me that I'm wrong.  It is an argument
> that is at least two decades old... 

Cheers,
Ben.

  parent reply	other threads:[~2010-06-11  1:14 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-06-08 14:26 [PATCH 0/6] OF device code merges and improvements Grant Likely
2010-06-08 14:26 ` Grant Likely
2010-06-08 14:26 ` [PATCH 1/6] of: Use full node name in resource structures Grant Likely
2010-06-08 14:26   ` Grant Likely
2010-06-08 14:26 ` [PATCH 2/6] of/device: merge of_device_uevent Grant Likely
2010-06-08 14:26   ` Grant Likely
2010-06-08 14:26 ` [PATCH 3/6] of: Modify of_device_get_modalias to be passed struct device Grant Likely
2010-06-08 14:26   ` Grant Likely
2010-06-08 14:26 ` [PATCH 4/6] of/device: Merge of_platform_bus_probe() Grant Likely
2010-06-08 14:26   ` Grant Likely
2010-06-08 14:26 ` [PATCH 5/6] of: Merge of_device_alloc Grant Likely
2010-06-08 14:26   ` Grant Likely
2010-06-08 14:26 ` [PATCH 6/6] of/device: populate platform_device (of_device) resource table on allocation Grant Likely
2010-06-08 14:26   ` Grant Likely
2010-06-08 15:57   ` Anton Vorontsov
2010-06-08 15:57     ` Anton Vorontsov
2010-06-08 16:02     ` Grant Likely
2010-06-08 16:02       ` Grant Likely
2010-06-08 16:46       ` Anton Vorontsov
2010-06-08 16:46         ` Anton Vorontsov
2010-06-08 18:41         ` Grant Likely
2010-06-08 18:41           ` Grant Likely
2010-06-08 19:48           ` Anton Vorontsov
2010-06-10  6:17             ` Benjamin Herrenschmidt
2010-06-10  6:17               ` Benjamin Herrenschmidt
2010-06-10 14:18               ` Grant Likely
2010-06-10 14:18                 ` Grant Likely
2010-06-10 15:13                 ` M. Warner Losh
2010-06-10 15:13                   ` M. Warner Losh
2010-06-10 15:47                   ` Anton Vorontsov
2010-06-10 15:47                   ` Anton Vorontsov
2010-06-10 16:01                     ` M. Warner Losh
2010-06-10 16:01                       ` M. Warner Losh
2010-06-10 16:52                       ` Anton Vorontsov
2010-06-10 17:09                         ` Mitch Bradley
2010-06-10 17:09                           ` Mitch Bradley
2010-06-10 17:20                           ` Grant Likely
2010-06-10 17:20                             ` Grant Likely
2010-06-10 17:09                         ` M. Warner Losh
2010-06-10 17:09                           ` M. Warner Losh
2010-06-11  1:14                       ` Benjamin Herrenschmidt [this message]
2010-06-10 16:30                     ` Grant Likely
2010-06-10 16:30                       ` Grant Likely
2010-06-10 17:10                       ` Anton Vorontsov
2010-06-10 17:10                         ` Anton Vorontsov
2010-06-10 17:21                         ` Grant Likely
2010-06-10 17:21                           ` Grant Likely
2010-06-10 15:47                   ` Anton Vorontsov
     [not found]                   ` <20100610.091357.513168276793712624.imp-uzTCJ5RojNnQT0dZR+AlfA@public.gmane.org>
2010-06-10 15:47                     ` Anton Vorontsov

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