nvmem-cells regression after adding 'call of_platform_populate() for MTD partitions'
Miquel Raynal
miquel.raynal at bootlin.com
Mon Dec 12 01:14:49 PST 2022
Hi Maxim,
bigunclemax at gmail.com wrote on Sun, 11 Dec 2022 11:26:29 +0300:
> >On 10.12.22 10:52, Maxim Kiselev wrote:
> >>
> >> After applying
> >
> >This makes me wonder: "applying" as in "applying it to some version that
> >doesn't contain this change normally" or as it "after it was applied to
> >mainline I have the following problem with vanilla kernel version <???>"?
>
> Sorry for confusing you, I mean "after it was applied to mainline".
> I have this problem with vanilla kernel version 6.0.
>
> >>> I faced with a problem that my ethernet device can't be probed because it
> >>> wait when 'nvmem-cells' device will be probed first.
> >>
> >>FWIW, there is a discussion about a problems that at least to my
> >>untrained eyes looks similar:
> >>https://lore.kernel.org/all/Yyj7wJlqJkCwObRn@lx2k/
>
> Yes it looks like the same issue.
>
>
> I think the root of the problem was the choice of 'compatible'
> device tree property to mark the mtd partition node as a nvmem provider.
>
> I'm talking about this part in 'mtd_nvmem_add' function.
> > config.no_of_node = !of_device_is_compatible(node, "nvmem-cells");
>
> Maybe we should change the 'compatible' property to something else?
At a first glance I don't get why the compatible would matter so much
here, can you point to some core DT logic that would have an effect? I
mean besides leading to the creation of a cell. IOW, what would be done
differently if the compatible was different?
Can you also dump the device links (if you can reach a prompt) from
sysfs?
In theory there should be a link between ethernet and spi-nor which is
fulfilled when the spi-nor device probes and leads to the creation of
device links. Maybe there is "something else" that the mtd core should
do, because this just works with eeproms (non-mtd cells), so let's find
out.
> сб, 10 дек. 2022 г. в 15:35, Thorsten Leemhuis <regressions at leemhuis.info>:
> >
> > [CCing the regression mailing list, as it should be in the loop for all
> > regressions, as explained in
> > https://docs.kernel.org/admin-guide/reporting-regressions.html ]
> >
> > Hi, this is your Linux kernel regression tracker. Thx for the report.
> >
> > On 10.12.22 10:52, Maxim Kiselev wrote:
> > >
> > > After applying
> >
> > This makes me wonder: "applying" as in "applying it to some version that
> > doesn't contain this change normally" or as it "after it was applied to
> > mainline I have the following problem with vanilla kernel version <???>"?
> >
> > > this commit 'mtd: call of_platform_populate() for MTD
> > > partitions' (bcdf0315),
> >
> > CCing Rafał, who authored bcdf0315.
> >
> > > I faced with a problem that my ethernet device can't be probed because it
> > > wait when 'nvmem-cells' device will be probed first.
> >
> > FWIW, there is a discussion about a problems that at least to my
> > untrained eyes looks similar:
> > https://lore.kernel.org/all/Yyj7wJlqJkCwObRn@lx2k/
> >
> > Rafał, has some progress been made to resolve this?
> >
> > To me it sounds like this might warrant a "revert, and reapply later
> > when the cause for the regression was addressed". Rafał, it seems you
> > suggested something like that, but it doesn't look like that happened
> > for one reason or another. Or am I missing something?
> >
> > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
> >
> > P.S.: As the Linux kernel's regression tracker I deal with a lot of
> > reports and sometimes miss something important when writing mails like
> > this. If that's the case here, don't hesitate to tell me in a public
> > reply, it's in everyone's interest to set the public record straight.
> >
> > > But there is no such driver which is compatible with 'nvmem-cells' because
> > > 'nvmem-cells' is just a mark used by the 'mtd_nvmem_add' function.
> > >
> > > So this leads to appeating of unresolved dependency for the ethernet device.
> > > And that's why the ethernet device can't be added and probed.
> > >
> > > Here is a part of kernel log when spi flash probe start:
> > >
> > >> device: 'spi0': device_add
> > >> device: 'spi0.0': device_add
> > >> spi-nor spi0.0: mx66l51235f (65536 Kbytes)
> > >> 7 fixed-partitions partitions found on MTD device spi0.0
> > >
> > > After 'm25p80' probe 'f1070000.ethernet' linked to 'partition at 1' :
> > >
> > >> device: 'f1010600.spi:m25p80 at 0:
> > > partitions:partition at 1': device_add
> > >> device: 'platform:f1010600.spi:m25p80 at 0:partitions:partition at 1--platform:f1070000.ethernet': device_add
> > >> devices_kset: Moving f1070000.ethernet to end of list
> > >> platform f1070000.ethernet: Linked as a consumer to f1010600.spi:m25p80 at 0:partitions:partition at 1
> > >> ethernet at 70000 Dropping the fwnode link to partition at 1
> > >
> > > And as a result I got `-EPROBE_DEFER` for `f1070000.ethernet`
> > >
> > >> platform f1070000.ethernet: error -EPROBE_DEFER: supplier f1010600.spi:m25p80 at 0:partitions:partition at 1 not ready
> > >
> > > Here is a part of my device tree:
> > >
> > > enet1: ethernet at 70000 {
> > > status = "okay";
> > > nvmem-cells = <&macaddr>;
> > > nvmem-cell-names = "mac-address";
> > > phy-mode = "rgmii";
> > > phy = <&phy0>;
> > > };
> > >
> > > spi at 10600 {
> > > status = "okay";
> > >
> > > m25p80 at 0 {
> > > compatible = "mx66l51235l";
> > > reg = <0>;
> > > #address-cells = <1>;
> > > #size-cells = <1>;
> > >
> > > partitions {
> > > compatible = "fixed-partitions";
> > > #address-cells = <1>;
> > > #size-cells = <1>;
> > >
> > > partition at 0 {
> > > reg = <0x00000000 0x000080000>;
> > > label = "SPI.U_BOOT";
> > > };
> > >
> > > partition at 1 {
> > > compatible = "nvmem-cells";
> > > reg = <0x000A0000 0x00020000>;
> > > label = "SPI.INV_INFO";
> > > #address-cells = <1>;
> > > #size-cells = <1>;
> > > ranges = <0 0x000A0000 0x00020000>;
> > >
> > > macaddr: mac at 6 {
> > > reg = <0x6 0x6>;
> > > };
> > > };
> > >
> > > };
> > > };
> > > };
> > >
> > > In the example above 'ethernet at 70000' requires 'macaddr: mac at 6' which is
> > > located inside mtd 'partition at 1' of 'm25p80 at 0' spi flash.
> >
> > P.P.S.: let me add this to the regression tracking:
> >
> > #regzbot ^introduced bcdf0315
> > #regzbot title mtd: ethernet device can't be probed anymore due to
> > broken nvmem-cells dep
> > #regzbot monitor: https://lore.kernel.org/all/Yyj7wJlqJkCwObRn@lx2k/
> > #regzbot ignore-activity
Thanks,
Miquèl
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