[U-Boot] [PATCH v3 3/8] ehci-hcd: Boost transfer speed

Marek Vasut marex at denx.de
Fri Aug 10 00:32:03 CEST 2012


Dear Benoît Thébaudeau,

> This patch takes advantage of the hardware EHCI qTD queuing mechanism to
> avoid software and transfer splitting overhead so as to make transfers as
> fast as possible.
> 
> The only drawback is a call to memalign. However, this is fast compared to
> the transfer timings, and the heap size to allocate is small, e.g. 128 kiB
> in the worst case for a transfer length of 65535 packets of 512 bytes.
> 
> Tested on i.MX25, i.MX35 and i.MX51. In my test conditions, the speed gain
> was very significant (several times faster), which is really appreciable
> when accessing large files.
> 
> Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau at advansee.com>
> Cc: Marek Vasut <marex at denx.de>
> Cc: Ilya Yanok <ilya.yanok at cogentembedded.com>
> Cc: Stefan Herbrechtsmeier <stefan at herbrechtsmeier.net>
[...]

Seems fine :)

Best regards,
Marek Vasut


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