Hi, >-----Original Message----- >From: Balbi, Felipe >Sent: Thursday, October 07, 2010 5:43 PM >To: Kalliguddi, Hema >Cc: Balbi, Felipe; David Brownell; >dbrownell@xxxxxxxxxxxxxxxxxxxxx; Arnaud Mandy; >linux-usb@xxxxxxxxxxxxxxx >Subject: Handling USB PHY IRQs (was: Re: [PATCH 2/2] usb: otg: >introduce otg_notify_event and otg_get_last_event) > >Hi, > >On Thu, Oct 07, 2010 at 06:52:08AM -0500, Kalliguddi, Hema wrote: >>Correct, so let's enable this VBUS PRESENCE IRQ in otg_init function >>which will be called during gadget driver load. And call the >VBUS PRESENCE >>irq handler to capture the status and send the notifications. > >It can't be done like this. What happen if user attaches the >cable while >there's no gadget driver loaded ? Even in that situation, we want to >be able to charge with a wall charger, host/hub charger or even normal >SDP (at 100mA limit). If we start depending on a gadget driver for the >phy to work, there's something wrong. > >>>Let's say we disable that logic. What will we use to detect >a USB cable >>>attach ? >>> >>The status will be logged when the cable is connected. But the IRQ is >>masked so, there will not be any IRQ. When link driver calls the >>otg_init enable the logic for VBUS PRESENCE interrupt and >call the VBUS >>PRESENCE IRQ handler. If the status bit set anyway the handler will >>send the notifications. > >how about a dedicated charger ? A gadget driver isn't needed, because >wall chargers have data lines shortened together. There won't be >enumeration in that case. > >Would you, please, explain the exact problem you're facing ? Without >that we will be running in circles here :-( >Even the dedicated charger also need to call the otg_init after registering for the notifications. I am not facing any problems. We can still use the status flags to get to know about the status of VBUS or ID GND in the driver probe. I was proposing another way get the events only when needed. >-- >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
