From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Thu, 17 Mar 2016 18:06:09 +0100 Subject: [v6, 5/5] mmc: sdhci-of-esdhc: fix host version for T4240-R1.0-R2.0 In-Reply-To: <20160317170101.GA21009@rob-hp-laptop> References: <1457518131-11339-1-git-send-email-yangbo.lu@nxp.com> <20160317170101.GA21009@rob-hp-laptop> Message-ID: <3706958.XeRFmKM0K5@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thursday 17 March 2016 12:01:01 Rob Herring wrote: > On Mon, Mar 14, 2016 at 05:45:43PM +0000, Scott Wood wrote: > > >> This makes the driver non-portable. Better identify the specific > > >> workarounds based on the compatible string for this device, or add a > > >> boolean DT property for the quirk. > > >> > > >> Arnd > > > > > > [Lu Yangbo-B47093] Hi Arnd, we did have a discussion about using DTS in v1 before. > > > https://patchwork.kernel.org/patch/6834221/ > > > > > > We don?t have a separate DTS file for each revision of an SOC and if we did, we'd constantly have people using the wrong one. > > > In addition, the device tree is stable ABI and errata are often discovered after device tree are deployed. > > > See the link for details. > > > > > > So we decide to read SVR from the device-config/guts MMIO block other than using DTS. > > > Thanks. > > > > Also note that this driver is already only for fsl-specific hardware, > > and it will still work even if fsl_guts doesn't find anything to bind to > > -- it just wouldn't be able to detect errata based on SVR in that case. > > IIRC, it is the same IP block as i.MX and Arnd's point is this won't > even compile on !PPC. It is things like this that prevent sharing the > driver. I think the first four patches take care of building for ARM, but the problem remains if you want to enable COMPILE_TEST as we need for certain automated checking. > Dealing with Si revs is a common problem. We should have a > common solution. There is soc_device for this purpose. Exactly. The last time this came up, I think we agreed to implement a helper using glob_match() on the soc_device strings. Unfortunately this hasn't happened then, but I'd still prefer that over yet another vendor-specific way of dealing with the generic issue. Arnd