Hi Nishanth, On 07/09/21 10:23 pm, Nishanth Menon wrote: > On 22:17-20210907, Aswath Govindraju wrote: >> Hi Nishanth, >> >> On 07/09/21 9:05 pm, Nishanth Menon wrote: >>> On 17:30-20210907, Jan Kiszka wrote: >>>> On 07.09.21 17:27, Nishanth Menon wrote: >>>>> On 17:20-20210907, Jan Kiszka wrote: >>>>>> On 07.09.21 17:13, Nishanth Menon wrote: >>>>>>> On 16:22-20210907, Jan Kiszka wrote: >>>>>>>> From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> >>>>>>>> >>>>>>>> This ensures that the SD card will remain mmc0 across Basic and Advanced >>>>>>>> devices, also avoiding surprises for users coming from the downstream >>>>>>>> kernels. >>>>>>>> >>>>>>>> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> >>>>>>>> --- >>>>>>>> arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts | 5 +++++ >>>>>>>> 1 file changed, 5 insertions(+) >>>>>>>> >>>>>>>> diff --git a/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts b/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts >>>>>>>> index ec9617c13cdb..d1d5278e0b94 100644 >>>>>>>> --- a/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts >>>>>>>> +++ b/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced.dts >>>>>>>> @@ -18,6 +18,11 @@ / { >>>>>>>> compatible = "siemens,iot2050-advanced", "ti,am654"; >>>>>>>> model = "SIMATIC IOT2050 Advanced"; >>>>>>>> >>>>>>>> + aliases { >>>>>>>> + mmc0 = &sdhci1; >>>>>>>> + mmc1 = &sdhci0; >>>>>>>> + }; >>>>>>> >>>>>>> >>>>>>> Should we do this at SoC level? >>>>>>> >>>>>> >>>>>> Well, I wouldn't mind - but that would also impact your EVMs. For us, >>>>>> this is fine as we are coming from that ordering above with our >>>>>> downstream kernel/dts. >>>>>> >>>>> >>>>> I think it'd probably be a welcome change. overall we've standardized on >>>>> partuuid. >>>>> >>>> >>>> Yeah, it's more about "dd if=emmc.img of=/dev/mmcblk1 - damn, the wrong >>>> one again." >>>> >>>> Let me know what you prefer, and I'll update my patch. >>> >>> >>> Lets do it at SoC level. I will follow it up with a patch for other K3 >>> SoCs as well. >>> >>> >>> Unless someone has a strong opinion on this approach - if so, speak up >>> with reasons. >>> >> >> Making this change in SoC level for all K3 devices would force changes >> to be made in U-Boot too, for consistency. In U-Boot, a major change >> would be required in the environment variables to support this. As I >> don't see any functional advantage by making this change, I feel that >> this change would make things more confusing for users already using the >> K3 devices. At present, the ordering is consistent across all the K3 >> devices, I feel that keeping it the same way would be better. >> >> As for making changes only on IoT boards, if it is okay to have the >> ordering changed between U-Boot and kernel, I don't see any problem >> making this change in kernel alone. > > > arch/arm64/boot/dts/ti/k3-am65.dtsi has no ordering. u-boot is supposed > to copy from kernel the dtsi files as is. I think having mmc aliases in > kernel is a good thing as we do regard kernel as the canonical dts > source. > Yes, you are correct. Aliases are not added for mmc in U-Boot too, but due to the ordering in the device tree, mmc0 is always sdhci0 and mmc1 is always sdhci1 in U-Boot. I agree that, in kernel as the probe order is not guaranteed, fixing the order would be better by adding aliases explicitly. > If you are suggesting we flip things so that mmc0 is sdhci0 and mmc1 is > sdhci1 - that might be a valid suggestion - Jan, do you see a problem > in having consistency here (flip the aliases)? > > Yes, I am suggesting a flip in the order and this order can be applied across all the K3 SoC's Thanks, Aswath