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@advansee.com Cc: Marek Vasut marex@denx.de Cc: Ilya Yanok ilya.yanok@cogentembedded.com Cc: Stefan Herbrechtsmeier stefan@herbrechtsmeier.net
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Seems fine :)
Best regards, Marek Vasut