On Thu, 26 May 2016, Martin Townsend wrote:

> Hi,
> 
> I'm currently trying to get the USB Host working on the SH7760.  I
> tried the platform driver to start with and get the following error on
> boot:
> [    3.600000] usb 1-1: new full-speed USB device number 2 using ohci-platform
> [    3.872000] ohci-platform ohci-platform: frame counter not updating; 
> disabled
> [    3.872000] ohci-platform ohci-platform: HC died; cleaning up
> 
> So I dug a bit further and see that the SH7760 driver in the 2.6
> kernel makes use of the 8KB shared memory for HCCA and ED/TD buffers.
> After looking through the code for the 4.1 Kernel I am currently
> trying to port to I think I need to write my own platform driver that
> calls dma_declare_coherent_memory so that the OHCI driver uses this
> 8KB shared memory.  Then set HCD_LOCAL_MEM in the hc_driver flags to
> ensure that it uses dma_alloc_coherent.  In other words copy what the
> ohci-sm501.c file is doing.  I just wanted to confirm that this is
> what I should be doing or is there a better generic way of telling the
> OHCI driver to use this 8KB shared memory.

There isn't a generic way of doing it, but you could such a thing to 
the ohci-platform driver.  That would be preferable to adding a new, 
separate platform driver.

Alan Stern

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