Hello Wolfram, On Tue, Oct 9, 2018 at 4:32 PM Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote: > > On Tue, Oct 09, 2018 at 03:47:24PM +0530, Silesh C V wrote: > > 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 <svellattu@xxxxxxxxxx> > > 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