On Tue, 2017-01-10 at 16:01 +0000, Ian Abbott wrote:
> Hi!
>
> I thought I'd try updating my custom SoCFPGA-based board from barebox
> 2016.11.0 to 2017.01.0, and have only run into one problem, which is
> that it is no longer loading the barebox environment during boot:
>
> barebox-environment environment.5: probe failed: No such device
> environment load /dev/env0: No such file or directory
> After a bit of poking around, I discovered that it is failing in
> __of_find_path() at these lines:
>
> if (!dev->driver)
> return -ENODEV;
>
> Those lines were added by commit
> 82eb3dff10ae0c0436e0fcd5ff0c9cd2a2caab3c ("of_path: handle no driver for
> device").
I assume the call to __of_find_path() is traced back to
environment_probe()?
It looks to me like the environment driver needs to be updated to
support PROBE_DEFER. It should detect ENODEV from of_find_path() as a
possible device not probed yet error and return PROBE_DEFER.
I wonder if of_find_path should return EPROBE_DEFER itself? It seems
like it might be easier to catch this in of_find_path() once instead of
in all callers of of_find_path().
> I'm not sure which bit of code is responsible for setting dev->driver
> (or whether it is appropriate in this case), but if I remove that test,
> the environment loads OK.
This makes me wonder if probe defer, which I think is still problem, is
not your problem.
> environment@0 {
> compatible = "barebox,environment";
> device-path = &flash, "partname:barebox-environment";
> &qspi {
> flash: flash@0 {
> partition@c0000 {
> label = "barebox-environment";
> reg = <0xc0000 0x20000>;
> };
In this case, the env points to the flash node for the specific chip
select, which is a child of the node for the qspi device. qspi has a
driver. But the child for the chip select isn't really a device in its
own right, it just part of the qspi device. I don't believe there is a
driver for it. I wonder if dev->driver will always be NULL for that
device?
Maybe the bug here is that a device node for a flash chip select or a
partition doesn't have a driver itself. So either the !dev->driver test
is wrong, or the device should have ->driver point to the driver of its
parent device.
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