Hi Peter, >> There is a core on mips which doesn't support otg. From my point of >> view, support for dual_role should be a separate patch, ideally by >> Svetoslav (Cc'ed) who has this hardware, after we've cleaned up all >> dr-mode related stuff. > >What means support OTG? The spec said it or there is a port >DCCPARAMS_DC =1 but DCCPARAMS_HC = 0? > >From my point, I still think if DCCPARAMS_DC = 1, it is save to >read OTGSC. >From the mailing list I see you already figured it out already. In my instance (AR9331 SoC) both DCCPARAMS_HC = 1 and DCCPARAMS_DC = 1. Even though the chipidea controller supports both modes, the implementation in the SoC doesn't map the OTGSC register in the address space. This makes it impossible to detect OTG support by relying on the register content only and the platform code needs to override the default behavior through dr_mode. Just for information the host/device mode on this platform can only be selected at boot, no switch is possible at runtime. Best regards, Svetoslav. -- 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