[U-Boot] [PATCH] USB:host: Attribute packed removed from usb structures

Amit Virdi amitvi128 at gmail.com
Wed Mar 7 14:49:53 CET 2012

On Wed, Mar 7, 2012 at 7:03 PM, Mike Frysinger <vapier at gentoo.org> wrote:
> On Wednesday 07 March 2012 03:23:42 Amit Virdi wrote:
>> >> I did the changes suggested by you and tested the build. The issue
>> >> didn't come up. Then I reverted the code to the original (attributes
>> >> retained and ehci directly de-referencing the pointers. The issue didn't
>> >> come here too.
>> >>
>> >> Today, I used armv7-linux-gcc (GCC) v4.6.2
>> >> So I suspect there has been some fix done in the GCC.
>> >>
>> >> Now, even with the packed attributes, the word fields are accessed
>> >> word-by-word in contrast to the earlier observed behavior
>> >> (byte-by-byte). I could see ldr and str in the disassembly.
>> >>
>> >> May be, we can discard this patch and keep drivers/usb/host/ehci.h
>> >> intact.
>> >
>> > not sure ... in general, device registers should be accessed with io.h
>> > helpers instead of dereferenced by volatile pointers.  i can think of
>> > cases on Blackfin where the io.h helpers would be required, and even
>> > using volatile pointers could result in misbehavior.
>> If you guys agree, I can float the patch but how can we distribute the
>> responsibility for testing on other architectures?
> if it works on your platform, and you compile it test it for others, and we
> agree it looks correct, and no one else wants to runtime test it to verify, i
> think it's fine to merge.  if there's a problem, someone will notice and let us
> know ;).

Ok Mike, agreed. Once I test it with ELDK 5.1, i'll inform you guys.

Amit Virdi

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