[PATCH 00/12] USB: chipidea: patchset for performance improvement

Jean-Christophe PLAGNIOL-VILLARD plagnioj at jcrosoft.com
Thu Mar 19 03:36:29 PDT 2015

On 09:19 Thu 19 Mar     , Peter Chen wrote:
> Hi all,
> In this patch set, I add some interfaces for tuning the performance
> of chipidea usb driver. With this set, the USB performance can be improved
> at some user cases with suitable parameters. The main changes:
> - Interface to tune interrupt threshold control, and set
> 'Immediate' for default value
> - The glue layer can disable stream mode according to USB role
> - Interface to tune AHB burst configuration at SBUSCFG
> - Interface to tune tx/rx burst size
> - i.mx changes for achieving better performance, it can reduce
>   the latecy between bus and USB FIFO, and reduce the overrun
>   and underrun occurrences, it is useful for the system bus is busy.
>   we see great improvement for ISO transfer, eg, high resolution
>   USB camera when the bus is busy.
> Below are some test results at imx6sx sdb board
> (set ehci_hcd.park=3 at bootargs), the tests are done
> at v4.0 kernel, no other bus loading during the tests,
> so we have not seen performance change for some use cases.
> USB Mass Storage (Host mode)
> With Patch Set		Without Patch Set
> R: 26.9 MB/s		27 MB/s
> W: 25.2 MB/s		24.5 MB/s
> 1G USB Ethernet Card
> With Patch Set		Without Patch Set
> TX: 186 Mb/s		185 Mb/s
> RX: 219 Mb/s		216 Mb/s
> g_ncm (Device Mode)
> With Patch Set		Without Patch Set
> TX: 166MB/s		163MB/s
> RX: 230MB/s		184MB/s

The improve is not drag sticks except for gcm RX

The most interesting path will be on full system loaded

can you test it and provide data?

Best Regards,

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