Hello, I was about to post this, and I noticed it has been discussed recently. http://thread.gmane.org/gmane.linux.kernel/2087677/ [PATCH] USB: USB_OTG does not depend on PM My SoC provides a Chipidea dual-port OTG USB 2.0 controller. My .config contains: CONFIG_USB_SUPPORT=y CONFIG_USB_COMMON=y CONFIG_USB_ARCH_HAS_HCD=y CONFIG_USB=y CONFIG_USB_ANNOUNCE_NEW_DEVICES=y ... CONFIG_USB_OTG=y # CONFIG_USB_OTG_WHITELIST is not set # CONFIG_USB_OTG_BLACKLIST_HUB is not set CONFIG_USB_OTG_FSM=y CONFIG_USB_EHCI_HCD=y CONFIG_USB_EHCI_ROOT_HUB_TT=y CONFIG_USB_EHCI_TT_NEWSCHED=y CONFIG_USB_OHCI_HCD=y CONFIG_USB_CHIPIDEA=y CONFIG_USB_CHIPIDEA_OF=y CONFIG_USB_CHIPIDEA_UDC=y CONFIG_USB_CHIPIDEA_HOST=y CONFIG_USB_CHIPIDEA_DEBUG=y When I build, I get this warning twice: (USB_OTG_FSM && FSL_USB2_OTG && USB_MV_OTG) selects USB_OTG which has unmet direct dependencies (USB_SUPPORT && USB && PM) I have a few questions: Is PM required for correct OTG functionality? Is USB_OTG_FSM required for correct OTG functionality? If so, shouldn't USB_CHIPIDEA_UDC depend on it? or select it? Also I'm confused by the help message for USB_CHIPIDEA: help Say Y here if your system has a dual role high speed USB controller based on ChipIdea silicon IP. Currently, only the peripheral mode is supported. If I set the dr_mode to "host", the OS correctly sees a mass storage device. (Which I took to mean host mode is supported.) Does it fail to work in "otg" mode? (I've ordered OTG cables to test this.) (I tested on v4.2 and I'm now working with v4.1) Regards. -- 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