Hello Wolfram,

On Tue, Oct 9, 2018 at 4:32 PM Wolfram Sang [off-list ref] wrote:

On Tue, Oct 09, 2018 at 03:47:24PM +0530, Silesh C V wrote:

quoted

Some drivers need to find the device on a bus having a specific firmware
node. Currently, such drivers have their own implementations to do this.
Provide a helper similar to bus_find_device_by_name so that each driver
does not have to reinvent this.

Signed-off-by: Silesh C V <redacted>

Looks good in general, however:

We recently had this discussion in I2C world about using the parent if
the (logical) device has a NULL fw_node [1]. I don't know if the other
subsystems you modify use logical devices as well? If no, it seems we
need an additional check for the parent in the I2C core only. If yes,
this might be considered in your patchset?

We can add an additional check for dev_fwnode(dev->parent) if match
for dev_fwnode(dev) fails in match_fwnode callback. Please correct me
if I am wrong. But then, we will be doing these two comparisons for
each device (until a match is found) on a bus for a bus_find_device
iteration(mostly unnecessarily because I could not find any "match
node" callbacks (for bus_find_device) currently doing this). So,
wouldn't it be better to add this check in exceptional cases (like in
the case of I2C) in the respective subsystems itself ?

Thanks,
Silesh