On Thu, May 26, 2016 at 4:24 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > 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 > Hi Alan, Thanks for the reply. So would that entail looking for a second IORESOURCE_MEM resource and taking this as the device's shared memory and if present call dma_declare_coherent_memory? Also how would I or in the HCD_LOCAL_MEM to flags to the hc_driver struct that's in ohci-hcd.c? Cheers, Martin. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
