Re: [PATCH v1 0/9] fw_devlink improvements

[Saravana Kannan <saravanak@xxxxxxxxxx>]

+Naresh Kamboju

On Tue, Aug 9, 2022 at 11:00 PM Saravana Kannan <saravanak@xxxxxxxxxx> wrote:
>
> This patch series improves fw_devlink in the following ways:
>
> 1. It no longer cares about a fwnode having a "compatible" property. It
>    figures this our more dynamically. The only expectation is that
>    fwnode that are converted to devices actually get probed by a driver
>    for the dependencies to be enforced correctly.
>
> 2. Finer grained dependency tracking. fw_devlink will now create device
>    links from the consumer to the actual resource's device (if it has one,
>    Eg: gpio_device) instead of the parent supplier device. This improves
>    things like async suspend/resume ordering, potentially remove the need
>    for frameworks to create device links, more parallelized async probing,
>    and better sync_state() tracking.
>
> 3. Handle hardware/software quirks where a child firmware node gets
>    populated as a device before its parent firmware node AND actually
>    supplies a non-optional resource to the parent firmware node's
>    device.
>
> 4. Way more robust at cycle handling (see patch for the insane cases).
>
> 5. Stops depending on OF_POPULATED to figure out some corner cases.
>
> 6. Simplifies the work that needs to be done by the firmware specific
>    code.
>
> This took way too long to get done due to typo bugs I had in my rewrite or
> corner cases I had to find and handle. But it's fairly well tested at this
> point and I expect this to work properly.
>
> Abel & Doug,
>
> This should fix your cyclic dependency issues with your display. Can you
> give it a shot please?
>
> Alexander,
>
> This should fix your issue where the power domain device not having a
> compatible property. Can you give it a shot please?
>
> Tony,
>
> This should handle the odd case of the child being the supplier of the
> parent. Can you please give this a shot? I want to make sure the cycle
> detection code handles this properly and treats it like it's NOT a cycle.
>
> Geert,
>
> Can you test the renesas stuff I changed please? They should continue
> working like before. Any other sanity test on other hardware would be
> great too.
>
> Sudeep,
>
> I don't think there are any unfixed issues you had reported in my other
> patches that this series might fix, but it'll be nice if you could give
> this a sanity test.
>
> Guenter,
>
> I don't think this will fix the issue you reported in the amba patch, but
> it's worth a shot because it improves a bunch of corner case handling. So
> it might be better at handling whatever corner cases you might have in the
> qemu platforms.

Hi Naresh,

Thanks for testing these patches in the other thread. Mind giving your
tested-by here? I know you tested these patches in X15, but were there
also other boards these patches were tested on as part of the run?

Thanks,
Saravana


>
> Thanks,
> Saravana
>
> Cc: Abel Vesa <abel.vesa@xxxxxxxxxx>
> Cc: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
> Cc: Tony Lindgren <tony@xxxxxxxxxxx>
> Cc: Sudeep Holla <sudeep.holla@xxxxxxx>
> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Cc: John Stultz <jstultz@xxxxxxxxxx>
> Cc: Doug Anderson <dianders@xxxxxxxxxxxx>
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
>
> Saravana Kannan (9):
>   driver core: fw_devlink: Don't purge child fwnode's consumer links
>   driver core: fw_devlink: Improve check for fwnode with no
>     device/driver
>   soc: renesas: Move away from using OF_POPULATED for fw_devlink
>   gpiolib: Clear the gpio_device's fwnode initialized flag before adding
>   driver core: fw_devlink: Add DL_FLAG_CYCLE support to device links
>   driver core: fw_devlink: Allow marking a fwnode link as being part of
>     a cycle
>   driver core: fw_devlink: Consolidate device link flag computation
>   driver core: fw_devlink: Make cycle detection more robust
>   of: property: Simplify of_link_to_phandle()
>
>  drivers/base/core.c             | 437 +++++++++++++++++++++-----------
>  drivers/gpio/gpiolib.c          |   6 +
>  drivers/of/property.c           |  84 +-----
>  drivers/soc/renesas/rcar-sysc.c |   2 +-
>  include/linux/device.h          |   1 +
>  include/linux/fwnode.h          |  12 +-
>  6 files changed, 323 insertions(+), 219 deletions(-)
>
> --
> 2.37.1.559.g78731f0fdb-goog
>