From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from void.printf.net (void.printf.net [89.145.121.20]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id E63F42C007E for ; Tue, 18 Sep 2012 15:07:46 +1000 (EST) From: Chris Ball To: Kumar Gala Subject: Re: [PATCH 2/3] powerpc/esdhc: add property to disable the CMD23 References: <1347347565-17474-1-git-send-email-Chang-Ming.Huang@freescale.com> <1347347565-17474-2-git-send-email-Chang-Ming.Huang@freescale.com> <20120911075429.GA27028@lizard> <20120911080457.GA28235@lizard> <110EED8CC96DFC488B7E717A2027A27C176170@039-SN1MPN1-002.039d.mgd.msft.net> <6D8C87BA-CA06-4215-94F5-63EBF5162B0A@kernel.crashing.org> <2A6FCAE3-288F-4972-90C0-15105932F13E@kernel.crashing.org> <87k3w0y5yn.fsf@octavius.laptop.org> <8B1F0805-759E-417A-B787-40DF197896F3@kernel.crashing.org> <110EED8CC96DFC488B7E717A2027A27C1785D0@039-SN1MPN1-002.039d.mgd.msft.net> <4E15F856-D385-40C4-A5FD-5F298C70F402@kernel.crashing.org> <1166FFD6-342F-4BDA-BF23-794DAEA95CC9@kernel.crashing.org> <110EED8CC96DFC488B7E717A2027A27C17DBCA@039-SN1MPN1-002.039d.mgd.msft.net> <02298E64-619A-4F41-A329-5FA3C909B224@kernel.crashing.org> Date: Tue, 18 Sep 2012 01:07:58 -0400 In-Reply-To: <02298E64-619A-4F41-A329-5FA3C909B224@kernel.crashing.org> (Kumar Gala's message of "Tue, 18 Sep 2012 00:00:55 -0500") Message-ID: MIME-Version: 1.0 Content-Type: text/plain Cc: "linux-mmc@vger.kernel.org" , Huang Changming-R66093 , "linuxppc-dev@lists.ozlabs.org list" , Anton Vorontsov List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, On Tue, Sep 18 2012, Kumar Gala wrote: >>>> I've got a mild preference for handling quirk assignment in the DT >>>> rather than in driver code, so I'd prefer to just push the original >>>> patch to mmc-next as-is. Does that sound okay? >>> >>> Why? I only ask because I agree with Scott that this means you have to >>> update your device tree to get proper functionality. >>> >> When the new silicon does not support CMD23, >> if we don't update the device tree, then we must update the SDHC driver. >> I prefer to add the property in device tree, >> because we just add this property in new device tree, we don't need more effort to modify driver. > > Jerry, > > I think doing it driver makes more sense because: > > 1. means older device tree's still work > 2. odds that CMD23 not being supported in future devices is near 0% > (Now that we support AutoCMD23 [and thus CMD23] we aren't likely to stop supporting it in future) > 3. If IP changes you are going to have to update driver anyways for new features > > I really think we should NOT utilize device tree for this. Of course, we could also make both (or perhaps neither) of you happy by merging both: if your DT says you don't support cmd23 *or* you hit the driver's blacklist, we avoid it. - Chris. -- Chris Ball One Laptop Per Child