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From: Vipin Kumar <vipin.kumar@st.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] USB:host: Attribute packed removed from usb structures
Date: Mon, 27 Feb 2012 12:46:39 +0530	[thread overview]
Message-ID: <4F4B2DD7.10009@st.com> (raw)
In-Reply-To: <4F48B3FB.20200@aribaud.net>

On 2/25/2012 3:42 PM, Albert ARIBAUD wrote:
> Hi Amit,
>

Hello Albert,

> Le 24/02/2012 12:58, Amit Virdi a ?crit :
>> From: Vipin Kumar<vipin.kumar@st.com>
>>
>> Packed attribute is forcing a bytewise write on device registers,
>> there by, resulting in a misbehavior on gcc-4.4.1.
>> Reverting the structures to non-packed
>
> If (just asking, not asserting) the issue is caused by fields being u8
> where u8 access is not possible, then should you not make the fields u16
> / u32 according to access requirements?
>

The problem is not with the fields being of a different width. AFAIK, 
the packed attribute changes the generated code to access even the word 
field elements in a byte by byte manner

Infact, there is a discussion on lkml that I can point
https://lkml.org/lkml/2011/4/27/278

It seems that the discussion did not lead to a conclusion but it was 
sensible (at least for ARM) to remove the packed attribute from this 
structure

Regards
Vipin

> Amicalement,

  reply	other threads:[~2012-02-27  7:16 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-24 11:58 [U-Boot] [PATCH] USB:host: Attribute packed removed from usb structures Amit Virdi
2012-02-24 19:18 ` Mike Frysinger
2012-02-27 10:02   ` Amit Virdi
2012-02-27 18:25     ` Mike Frysinger
2012-02-25 10:12 ` Albert ARIBAUD
2012-02-27  7:16   ` Vipin Kumar [this message]
2012-02-27 13:14     ` Marek Vasut
2012-02-27 18:26       ` Mike Frysinger
2012-02-27 20:53         ` Marek Vasut
2012-02-28  0:56           ` Mike Frysinger
2012-02-29 10:25             ` Amit Virdi
2012-03-06 12:06               ` Amit Virdi
2012-03-06 12:51                 ` Marek Vasut
2012-03-07  8:30                   ` Amit Virdi
2012-03-07 11:38                     ` Marek Vasut
2012-03-07 12:12                       ` Amit Virdi
2012-03-06 16:11                 ` Mike Frysinger
2012-03-07  8:23                   ` Amit Virdi
2012-03-07 13:33                     ` Mike Frysinger
2012-03-07 13:49                       ` Amit Virdi

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