From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <471F5576.4060603@ru.mvista.com> Date: Wed, 24 Oct 2007 18:23:50 +0400 From: Valentine Barshak MIME-Version: 1.0 To: Dale Farnsworth Subject: Re: [PATCH] PowerPC 440EPx Sequoia USB OHCI DTS entry References: <20071008142658.GA15197@ru.mvista.com> <20071023214000.424.qmail@farnsworth.org> <471F2A32.8030202@ru.mvista.com> <20071024120804.GA1180@xyzzy.farnsworth.org> <471F4C53.1070506@ru.mvista.com> <20071024141041.GA13586@xyzzy.farnsworth.org> In-Reply-To: <20071024141041.GA13586@xyzzy.farnsworth.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: Linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Dale Farnsworth wrote: > On Wed, Oct 24, 2007 at 05:44:51PM +0400, Valentine Barshak wrote: >> Dale Farnsworth wrote: >>> On Wed, Oct 24, 2007 at 03:19:14PM +0400, Valentine Barshak wrote: >>>> Dale Farnsworth wrote: >>>>> Valentine wrote: >>>>>> Actually I also don't see much reason for the >>>>>> USB_OHCI_HCD_PPC_OF_BE/USB_OHCI_HCD_PPC_OF_LE stuff. >>>>>> Is this really needed? >>>>> I think so. The SOC host controllers are BE and the PCI >>>>> host controllers are LE. Or, do you have an alternative >>>>> method of handling both types? >>>> Yes, PCI controllers are LE, but do we really need user-selectable >>>> USB_OHCI_HCD_PPC_OF_LE option, since USB_OHCI_LITTLE_ENDIAN is selected >>>> by default for USB_OHCI_HCD_PCI? >>>> The USB_OHCI_HCD_PPC_OF_LE/BE stuff is related to PPC OF glue only. >>>> I think it's useless. We should always enable >>>> USB_OHCI_BIG_ENDIAN_DESC and USB_OHCI_BIG_ENDIAN_MMIO for PPC OF >>>> and the real LE/BE implementation should be selected by the >>>> corresponding properties in the device tree. >>> I agree that they don't need to be user selectable. It is far preferable >>> to deduce their values from existing information, if possible. >>> >>> -Dale >> This is the original thread: >> http://ozlabs.org/pipermail/linuxppc-embedded/2006-November/025054.html >> >> I think the USB_OHCI_HCD_PPC_OF_LE/BE should be removed. >> We can't avoid the slight overhead even using these options, since >> USB_OHCI_BIG_ENDIAN_MMIO/DESC should always be anabled for PPC OF and we >> we still enable USB_OHCI_LITTLE_ENDIAN for USB_OHCI_HCD_PCI even if >> USB_OHCI_HCD_PPC_OF_LE is not set. > > I believe you are saying that we can select any valid combination > of USB_OHCI_BIG_ENDIAN_DESC, USB_OHCI_BIG_ENDIAN_MMIO, and > USB_OHCI_LITTLE_ENDIAN, without using USB_OHCI_HCD_PPC_OF_BE and > USB_OHCI_HCD_PPC_OF_LE. I agree. It looks like we can get rid of > these last two with zero loss in performance or functionality. > > Do you have a patch? No I don't have it yet :) I planed to make, test and submit it a bit later. Thanks, Valentine. > > -Dale