On Sun, 23 Jun 2013, Manjunath Goudar wrote: > > As a general rule, you should never change code that you don't > > understand. Do you _know_ that it will be safe to call ohci_setup() or > > ohci_restart() at this point? > > > > > From David Brownell comment I am understanding,instead of calling > ohci_setup() > or ohci_restart(),we can use directly below code. > > ohci->hc_control &= OHCI_CTRL_RWC; > ohci_writel (ohci, ohci->hc_control, &ohci->regs->control); > ohci->rh_state = OHCI_RH_HALTED; Of course you can use that code; that's exactly what ohci_usb_reset() does now. > the 3rd line code is written by you,I want to know what exactly it is doing. > Is it required here? Yes, it is required. ohci->rh_state stores the current state of the root hub. When the controller is reset, the root hub goes into the HALTED state; this line records that fact. > > It might be a good idea to get in touch with the person who wrote that > > routine originally and ask why they used ohci_usb_reset(). > > > > yes I will. > > Hi David, > > As I understood ohci_usb_reset() is calling for to notice > disconnect,reconnect, > or wakeup without the 48 MHz clock active. > After fix power management hanging(869aa98c) issue by Patrice Vilchez,I > think > ohci_usb_reset() is not required to call. what is your opinion about this. Sadly, David Brownell died in 2011. I can tell you, though, that commit 869aa98c does not eliminate the need to call ohci_usb_reset(). Alan Stern -- 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
