Re: fw_devlink=on breaks probing devices when of_platform_populate() is used

["Rafał Miłecki" <zajec5@gmail.com>]

On 30.07.2022 09:36, Rafał Miłecki wrote:
> On 16.07.2022 22:50, Rafał Miłecki wrote:
>> I added of_platform_populate() calls in mtd subsystem in the commit
>> bcdf0315a61a2 ("mtd: call of_platform_populate() for MTD partitions"):
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=bcdf0315a61a29eb753a607d3a85a4032de72d94
>>
>> I recently backported that commit in OpenWrt to kernels 5.10 and 5.15.
>> We started receiving reports that probing Ethernet devices stopped
>> working in kernel 5.15. I bisected it down to the kernel 5.13 change:
>>
>> commit ea718c699055c8566eb64432388a04974c43b2ea (refs/bisect/bad)
>> Author: Saravana Kannan <saravanak@google.com>
>> Date:   Tue Mar 2 13:11:32 2021 -0800
>>
>>      Revert "Revert "driver core: Set fw_devlink=on by default""
>>
>>      This reverts commit 3e4c982f1ce75faf5314477b8da296d2d00919df.
>>
>>      Since all reported issues due to fw_devlink=on should be addressed by
>>      this series, revert the revert. fw_devlink=on Take II.
>>
>>      Signed-off-by: Saravana Kannan <saravanak@google.com>
>>      Link: https://lore.kernel.org/r/20210302211133.2244281-4-saravanak@google.com
>>      Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>>
>> For me with above commit kernel just never calls bcm4908_enet_probe().
>> Reverting it from the top of 5.13.19 and 5.15.50 fixes it. I believe the
>> same issue happens with other drivers.
>>
>> Critical detail is that in DT Ethernet block node references NVMEM cell
>> of MTD partition (see below).
>>
>> Could you help me dealing with this issue, please? Can you see something
>> obvious breaking fw_devlink=on + of_platform_populate() case? Can I
>> provide some extra information to help fixing it?
> 
> Any ideas about this problem / solution?

I didn't get any reponse for this bug for 6 weeks now. Is that OK if I
send a revert patch then?


>> Relevant DT part:
>>
>> partitions {
>>      compatible = "fixed-partitions";
>>      #address-cells = <1>;
>>      #size-cells = <1>;
>>
>>      partition@0 {
>>          compatible = "nvmem-cells";
>>          reg = <0x0 0x100000>;
>>          label = "bootloader";
>>
>>          #address-cells = <1>;
>>          #size-cells = <1>;
>>          ranges = <0 0x0 0x100000>;
>>
>>          base_mac_addr: mac@106a0 {
>>              reg = <0x106a0 0x6>;
>>          };
>>      };
>>
>>      partition@100000 {
>>          reg = <0x100000 0x5700000>;
>>          label = "firmware";
>>      };
>> };
>>
>> ethernet@2000 {
>>      compatible = "brcm,bcm4908-enet";
>>      reg = <0x2000 0x1000>;
>>
>>      interrupts = <GIC_SPI 86 IRQ_TYPE_LEVEL_HIGH>,
>>              <GIC_SPI 87 IRQ_TYPE_LEVEL_HIGH>;
>>      interrupt-names = "rx", "tx";
>>
>>      nvmem-cells = <&base_mac_addr>;
>>      nvmem-cell-names = "mac-address";
>> };
>>
>> OpenWrt bug report:
>> https://github.com/openwrt/openwrt/issues/10232