[U-Boot] [PATCH v2 11/17] usb: Add support for data alignment

Remy Bohmer linux at bohmer.net
Sat Dec 10 17:04:08 CET 2011


Hi Simon,

2011/12/6 Simon Glass <sjg at chromium.org>:
>>
>> I do not really like this solution. Maybe we can introduce something
>> like an usbbuf_alloc() function that takes care of the alignment.
>> This saves the memcpy() for every transmit. I know it has more impact
>> if we do it like that, but I think it is cleaner.
>
> This is called from usb_bulk_msg() which is called from usb_storage
> and USB ethernet drivers. A similar problem happened in the MMC stack
> and was fixed by changing all the callers to cache-align their
> buffers.
>
> Do you mean that you want a patch which changes the callers so that
> they align their data to a cache boundary as with MMC? Given the small
> number of callers at this stage it shouldn't be too hard. Then we
> could drop this patch.
>
> Please let me know.

That is fine with me too.

Kind regards,

Remy


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