On 12:23 Sat 17 Sep , Russell King - ARM Linux wrote: > On Sat, Sep 17, 2011 at 12:34:57PM +0200, Jean-Christophe PLAGNIOL-VILLARD wrote: > > On 11:28 Sat 17 Sep , Russell King - ARM Linux wrote: > > > One last point to raise here is - and it's quite a fundamental one - do we > > > really want this? If we're making decisions based on the SoC type, that > > > suggests to me that the hardware description in DT is incomplete, and > > > we're hiding stuff in the kernel behind the SoC type. That doesn't sound > > > particularly appealing given the point of DT is to encode the hardware > > > specific information outside the kernel code. > > > > except if a machine can run on 2 soc so detect it will avoid to have 2 Device > > Tree > > This code is structured to match the SoC based upon an entry in the DT, > so for tegra2 vs tegra3 it's already having to have two different DTs > to distinguish between them. > > However, I still go back to my original point: the point of DT is to > provide a description of the hardware which the kernel is running on - > not only for current hardware but possibly future hardware as well. Eg, > if Tegra4 comes along with more peripherals than Tegra3 but has basic > hardware which the kernel already supports, just wired up differently, > then Tegra4 should just work with a new DT file and no code changes. > > What I'm saying is that in that scenario it should not be necessary to > edit the kernel to invent new SoC types, and then teach it that Tegra4 > is mostly the same as Tegra3. That information should all be encoded > into the DT rather than the C code in the kernel. > > So, I think adding this SoC type stuff is the wrong approach to the > problem. I agree about it I just mean that if you have the same board with 2 SoC which are pin to pin compatible detect the soc type will be usefull as the soc resource may not be the same Best Regards, J. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
