[U-Boot] USB keyboard does not work on DWC2 controller (on Raspberry Pi B)
Guillaume Gardet
guillaume.gardet at free.fr
Tue Aug 18 13:55:42 CEST 2015
Hi Stephen,
I want to add USB keyboard support to raspberry pi but I get the following error when I do 'usb start' with a keyboard plugged-in:
unable to get device descriptor (error=-22)
Ethernet chip and mass storage devices are found.
I found this thread from February: http://lists.denx.de/pipermail/u-boot/2015-February/206593.html
which says:
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This error is because the keyboard driver uses interrupt transfers, and
these aren't implemented in DWC2
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But in April, you added a patch series including "usb: dwc2: implement interrupt transfers".
But there is also a note:
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With all these commits applied, both my USB keyboards (one LS Lenovo and
one FS Dell) work correctly when there is no USB hub between the SoC and
the keyboard; We still need split transactions to be implemented for hubs
to work.
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So, I guess this is expected that USB keyboard does not work on DWC2 / RPi B since it uses a USB hub (SMSC LAN9512)?
Guillaume
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