| Message ID | 20240927-leds_device_for_each_child_node_scoped-v1-0-95c0614b38c8@gmail.com |
|---|---|
| Headers | show |
| Series | leds: switch to device_for_each_child_node_scoped() | expand |
On Fri, Sep 27, 2024 at 1:21 AM Javier Carrasco <javier.carrasco.cruz@gmail.com> wrote: > > Switch to device_for_each_child_node_scoped() to simplify the code by > removing the need for calls to fwnode_handle_put() in the error paths. > > This also prevents possible memory leaks if new error paths are added > without the required call to fwnode_handle_put(). > > After switching to the scoped variant, there is no longer need for a > jump to 'err_node_out', as an immediate return is possible. > > Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com> > --- Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
On Fri, 27 Sep 2024 01:20:51 +0200, Javier Carrasco wrote: > This series switches from the device_for_each_child_node() macro to its > scoped variant, which in general makes the code more robust if new early > exits are added to the loops, because there is no need for explicit > calls to fwnode_handle_put(). Depending on the complexity of the loop > and its error handling, the code gets simplified and it gets easier to > follow. > > [...] Applied, thanks! [01/18] leds: flash: mt6360: fix device_for_each_child_node() refcounting in error paths commit: 73b03b27736e440e3009fe1319cbc82d2cd1290c [02/18] leds: flash: mt6370: switch to device_for_each_child_node_scoped() commit: 19d1cc765e7d477070ddda02c9a07a1ebcdf4b2d [03/18] leds: flash: leds-qcom-flash: switch to device_for_each_child_node_scoped() commit: f64dd42a4f939fb5acc3f3568ef2118487617996 [04/18] leds: aw200xx: switch to device_for_each_child_node_scoped() commit: a361af3c1622d4b8ede54493fa88633fb12201d0 [05/18] leds: cr0014114: switch to device_for_each_child_node_scoped() commit: 65135e2ccf5ad0853c1df0ffeefc372066a62909 [06/18] leds: el15203000: switch to device_for_each_child_node_scoped() commit: 9e445e28ae0c6fe24369127cf2302cd4f3a1b42b [07/18] leds: gpio: switch to device_for_each_child_node_scoped() commit: 42b49671602f9badb14fd2c32e6791a24d8cbf02 [08/18] leds: lm3532: switch to device_for_each_child_node_scoped() commit: 7bd4b9277b9831d115f14d26000c0ba32c83d109 [09/18] leds: lm3697: switch to device_for_each_child_node_scoped() commit: 6e2d1d83b70bd736228529fd1cb4f98e0ab77eb8 [10/18] leds: lp50xx: switch to device_for_each_child_node_scoped() commit: ba35b9a4c1b074218880c47ca09d19a3c69f904d [11/18] leds: max77650: switch to device_for_each_child_node_scoped() commit: 4ab3ae432da1706b5e1624ecea3c670faaec39d7 [12/18] leds: ns2: switch to device_for_each_child_node_scoped() commit: 5b5d936db0d2fb9e81d240ed91d062b8c8f0d224 [13/18] leds: pca963x: switch to device_for_each_child_node_scoped() commit: dea90acb09324efe640ab69766c12d8d387ee97f [14/18] leds: pwm: switch to device_for_each_child_node_scoped() commit: e3456071853597229012622c97b76109c0fa8754 [15/18] leds: sun50i-a100: switch to device_for_each_child_node_scoped() commit: 8cf103de9a002fb02125491c06d9cd60762d70e5 [16/18] leds: tca6507: switch to device_for_each_child_node_scoped() commit: 01728d041986a6992d0b2499e88db4569e65a535 [17/18] leds: rgb: ktd202x: switch to device_for_each_child_node_scoped() commit: 48259638fe5986afe8ed2a49e35f0641d953c311 [18/18] leds: rgb: mt6370: switch to device_for_each_child_node_scoped() commit: bf3fba727695dcd1ac3f9d17d88845223f56c14f -- Lee Jones [李琼斯]
Fri, Sep 27, 2024 at 01:20:51AM +0200, Javier Carrasco kirjoitti: > This series switches from the device_for_each_child_node() macro to its > scoped variant, which in general makes the code more robust if new early > exits are added to the loops, because there is no need for explicit > calls to fwnode_handle_put(). Depending on the complexity of the loop > and its error handling, the code gets simplified and it gets easier to > follow. > > The non-scoped variant of the macro is error-prone, and it has been the > source of multiple bugs where the child node refcount was not > decremented accordingly in error paths within the loops. The first patch > of this series is a good example, which fixes that kind of bug that is > regularly found in node iterators. > > The uses of device_for_each_child_node() with no early exits have been > left untouched because their simpilicty justifies the non-scoped > variant. > > Note that the child node is now declared in the macro, and therefore the > explicit declaration is no longer required. > > The general functionality should not be affected by this modification. > If functional changes are found, please report them back as errors. Thank you for this series. It may now benefit from the next steps: 1) converting to return dev_err_probe() or dev_warn_probe() directly since the goto had been replaced by direct return, hence saving even more LoCs; 2) dropping or refactoring the complex conditions due to your nice series being applied. I'll comment individually on some to show what I meant by the above.
This series switches from the device_for_each_child_node() macro to its scoped variant, which in general makes the code more robust if new early exits are added to the loops, because there is no need for explicit calls to fwnode_handle_put(). Depending on the complexity of the loop and its error handling, the code gets simplified and it gets easier to follow. The non-scoped variant of the macro is error-prone, and it has been the source of multiple bugs where the child node refcount was not decremented accordingly in error paths within the loops. The first patch of this series is a good example, which fixes that kind of bug that is regularly found in node iterators. The uses of device_for_each_child_node() with no early exits have been left untouched because their simpilicty justifies the non-scoped variant. Note that the child node is now declared in the macro, and therefore the explicit declaration is no longer required. The general functionality should not be affected by this modification. If functional changes are found, please report them back as errors. Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com> --- Javier Carrasco (18): leds: flash: mt6360: fix device_for_each_child_node() refcounting in error paths leds: flash: mt6370: switch to device_for_each_child_node_scoped() leds: flash: leds-qcom-flash: switch to device_for_each_child_node_scoped() leds: aw200xx: switch to device_for_each_child_node_scoped() leds: cr0014114: switch to device_for_each_child_node_scoped() leds: el15203000: switch to device_for_each_child_node_scoped() leds: gpio: switch to device_for_each_child_node_scoped() leds: lm3532: switch to device_for_each_child_node_scoped() leds: lm3697: switch to device_for_each_child_node_scoped() leds: lp50xx: switch to device_for_each_child_node_scoped() leds: max77650: switch to device_for_each_child_node_scoped() leds: ns2: switch to device_for_each_child_node_scoped() leds: pca963x: switch to device_for_each_child_node_scoped() leds: pwm: switch to device_for_each_child_node_scoped() leds: sun50i-a100: switch to device_for_each_child_node_scoped() leds: tca6507: switch to device_for_each_child_node_scoped() leds: rgb: ktd202x: switch to device_for_each_child_node_scoped() leds: rgb: mt6370: switch to device_for_each_child_node_scoped() drivers/leds/flash/leds-mt6360.c | 3 +-- drivers/leds/flash/leds-mt6370-flash.c | 11 +++------- drivers/leds/flash/leds-qcom-flash.c | 4 +--- drivers/leds/leds-aw200xx.c | 7 ++----- drivers/leds/leds-cr0014114.c | 4 +--- drivers/leds/leds-el15203000.c | 14 ++++--------- drivers/leds/leds-gpio.c | 9 +++------ drivers/leds/leds-lm3532.c | 18 +++++++---------- drivers/leds/leds-lm3697.c | 18 ++++++----------- drivers/leds/leds-lp50xx.c | 21 +++++++------------ drivers/leds/leds-max77650.c | 18 ++++++----------- drivers/leds/leds-ns2.c | 7 ++----- drivers/leds/leds-pca963x.c | 11 +++------- drivers/leds/leds-pwm.c | 15 ++++---------- drivers/leds/leds-sun50i-a100.c | 27 +++++++++---------------- drivers/leds/leds-tca6507.c | 7 ++----- drivers/leds/rgb/leds-ktd202x.c | 8 +++----- drivers/leds/rgb/leds-mt6370-rgb.c | 37 ++++++++++------------------------ 18 files changed, 75 insertions(+), 164 deletions(-) --- base-commit: 92fc9636d1471b7f68bfee70c776f7f77e747b97 change-id: 20240926-leds_device_for_each_child_node_scoped-5a95255413fa Best regards,