On Wed, Oct 26, 2016 at 06:55:22AM +0000, M.H. Lian wrote: > Hi Robin, > > Please see my comments inline. > > Thanks, > Minghuan > > > -----Original Message----- > > From: Robin Murphy [mailto:robin.murphy@xxxxxxx] > > Sent: Tuesday, October 25, 2016 9:01 PM > > To: M.H. Lian <minghuan.lian@xxxxxxx>; linux-arm- > > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > > devicetree@xxxxxxxxxxxxxxx > > Cc: Marc Zyngier <marc.zyngier@xxxxxxx>; Stuart Yoder > > <stuart.yoder@xxxxxxx>; Leo Li <leoyang.li@xxxxxxx>; Scott Wood > > <scott.wood@xxxxxxx>; Shawn Guo <shawnguo@xxxxxxxxxx>; Mingkai Hu > > <mingkai.hu@xxxxxxx> > > Subject: Re: [PATCH 1/6] dt/bindings: adjust bindings for Layerscape SCFG > > MSI > > > > On 25/10/16 13:35, Minghuan Lian wrote: > > > 1. The different version of a SoC may have different MSI > > > implementation. But compatible "fsl,<soc-name>-msi" can not describe > > > the SoC version. > > > > Can't it? > > > > compatible = "fsl-ls1043a-rev11-msi"; > > > > Oh, I guess it can! > > > > Joking aside, if there are multiple versions of a piece of hardware which > > require *different* treatment by drivers, then it is obviously wrong to use > > the same compatible string because *they are not compatible*. > > > [Minghuan Lian] Yes, but Rev1.0 and Rev1.1 SoC will use the same dts files. > We cannot create different dts files for each revision of the same kind of SoC. ... why? The DT should describe the hardware; if hardware differs then it should have a different DT. > It means that there are different variants in the different versions > of the same SoC that will use the same compatible string. Why can you not add a string for each variant, in addition to the SoC string? We do that elsewhere. > So I have to use SoC match interface to get the versions. > > I'm too radical. I do not want to first check SoC family via > compatible string and then check revision via SoC match or SVR. You can have *both* in the the compatible string list, e.g. at the top level: compatible = "vendor,soc-rev", "vendor-soc"; For devices which differ, this can be encoded similarly in the device compatible string list. > I selected the "SoC match" like the following to get the related information at only one place. > > static struct soc_device_attribute soc_msi_matches[] = { > { .family = "QorIQ LS1021A", > .data = &ls1021_msi_cfg }, > { .family = "QorIQ LS1012A", > .data = &ls1021_msi_cfg }, > { .family = "QorIQ LS1043A", .revision = "1.0", > .data = &ls1021_msi_cfg }, > { .family = "QorIQ LS1043A", .revision = "1.1", > .data = &ls1043_rev11_msi_cfg }, > { .family = "QorIQ LS1046A", > .data = &ls1046_msi_cfg }, > { }, > }; > > I will remain the SoC related compatible and try to describe the > difference via some kind of the property. As commented on the driver side, this should be described with DT properties on the devices. Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
