On Jun 2, 2014, at 11:23 AM, Grant Likely <grant.likely@xxxxxxxxxx> wrote: > On Mon, 2 Jun 2014 10:40:30 -0500, Kumar Gala <galak@xxxxxxxxxxxxxx> wrote: >> >> On Jun 2, 2014, at 10:09 AM, Grant Likely <grant.likely@xxxxxxxxxx> wrote: >> >>> On Sat, 31 May 2014 20:41:04 +0200, Arnd Bergmann <arnd@xxxxxxxx> wrote: >>>> On Saturday 31 May 2014 01:36:40 Liviu Dudau wrote: >>>>> We would like to be able to describe PCIe ECAM resources as >>>>> IORESOURCE_MEM blocks while distinguish them from standard >>>>> memory resources. Add an IORESOURCE_BIT entry for this case. >>>>> >>>>> Signed-off-by: Liviu Dudau <Liviu.Dudau@xxxxxxx> >>>> >>>> I still don't see any value in this at all. What is the advantage >>>> of doing this opposed to just having a standardized 'reg' property >>>> for a particular compatible string? >>> >>> I'm inclined to agree. It doesn't seem appropriate to put config space >>> in ranges, and the host controller binding is responsible for >>> identifying how config space is memory mapped. >>> >>> g. >> >> I don’t agree when it comes to ECAM, but we can drop this for now >> until someone really does that. > > Okay, humor me then. What would a ranges property look like for ECAM? Do > you have an example? I believe there would need to be a separate entry > for each and every PCI device on the bus to get the config spaces to be > contiguous. The definition of ECAM is a 256M linear region with each 4k being a different bus/dev/func. So the ranges would look something like: ranges = <0x00000000 0 0x00000000 0x0ff00000 0 0x10000000> /* configuration space */ The reason I think allow an ECAM makes sense in ranges is because it allows for a direct IO read/write to CFG space (w/o any mapping) similar to what one would do for MEM space or IO. > However, what do we do with the 2 cases that exist in upstream that >> are using ranges for cfg space? > > Ignore them in the core code? Make the specific host controller handle > them I would think. I just meant, should we ‘break’ their DTs and move them from using ranges to reg? - k > -- > To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
