>-----Original Message----- >From: linux-usb-owner@xxxxxxxxxxxxxxx >[mailto:linux-usb-owner@xxxxxxxxxxxxxxx] On Behalf Of Balbi, Felipe >Sent: Wednesday, October 06, 2010 6:35 PM >To: David Brownell >Cc: Balbi, Felipe; dbrownell@xxxxxxxxxxxxxxxxxxxxx; Arnaud >Mandy; felipe.balbi@xxxxxx; linux-usb@xxxxxxxxxxxxxxx >Subject: Re: [PATCH 2/2] usb: otg: introduce otg_notify_event >and otg_get_last_event > >On Wed, Oct 06, 2010 at 05:29:33AM -0500, David Brownell wrote: >> >>> what happens, then, if e.g. device has usb charging and >>> devicde starts >>> to boot when you connect usb cable. Then, by the time link >>> (in this case >>> musb) probes it will have lost the VBUS notification from phy. >> >>That should be trivial: enter the B-mode OTG >>stage machine and set the relevant flags, as well >>as updating the OTG state. Remember it doesn't >>care about the notification, just the OTG state. >> >>The transceiver/phy driver can do that. >> >> Link needs to know about that somehow. >> >>It can see that the otg_transceiver's default_a >>flag is clear. Probably doesn't want to switch >>on all the default-b states, for simplicity. > >We want to keep link powered down until we get a) VBUS IRQ or b) ID pin >IRQ. There's no point turning it on before that since USB cable isn't >connected anyway. If you say checking xceiv->state is enough, then it's >enough :-p > How about enabling these OTG interrupts(VBUS and ID) only when the user calls like xceiv->otg_init function in the driver probe. In the otg_init function call the irq handlers which will catch the status and send the events? With this we can avoid the unnecessary interrupts when the user modules are not loaded. >-- >balbi >-- >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 >-- 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
