From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 7BB672C0091 for ; Tue, 18 Sep 2012 15:01:07 +1000 (EST) Subject: Re: [PATCH 2/3] powerpc/esdhc: add property to disable the CMD23 Mime-Version: 1.0 (Apple Message framework v1278) Content-Type: text/plain; charset=us-ascii From: Kumar Gala In-Reply-To: <110EED8CC96DFC488B7E717A2027A27C17DBCA@039-SN1MPN1-002.039d.mgd.msft.net> Date: Tue, 18 Sep 2012 00:00:55 -0500 Message-Id: <02298E64-619A-4F41-A329-5FA3C909B224@kernel.crashing.org> 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> To: Huang Changming-R66093 Cc: "linux-mmc@vger.kernel.org" , Chris Ball , "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: , On Sep 17, 2012, at 8:09 PM, Huang Changming-R66093 wrote: >> On Sep 17, 2012, at 7:36 AM, Chris Ball wrote: >>=20 >>> Hi, >>>=20 >>> On Thu, Sep 13 2012, Kumar Gala wrote: >>>>>> Can you list out which SoCs support it and which don't. Having >>>>>> this list will be useful in understanding which controller = versions >> supported it. >>>>>>=20 >>>>> P1020, p1021, p1022, p1024, p1015 and p4080 can't support it. >>>>> Mpc8536, p2020, and the other current DPAA silicon (e.g. p5020, = p3041) >> support it. >>>>=20 >>>> Based on this, why don't we use the HOSTVER register to detect = instead >> of device tree: >>>=20 >>> 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? >>=20 >> Why? I only ask because I agree with Scott that this means you have = to >> update your device tree to get proper functionality. >>=20 > 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. >=20 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. - k