[PATCH 00/36] treewide: remove conditional returns with no effect

[PATCH 00/36] treewide: remove conditional returns with no effect

[Sang-Heon Jeon]

Hello,

While reading mm/memblock, I found a conditional return where both
branches return the same value:

	err = do_something();
	if (err)
		return err;
	return err;

Such code is usually a leftover from removing a statement between
the two returns, and the tree has about a hundred of these.

Patch 1 adds a Coccinelle script that matches the pattern, including
negation and constant-comparison variants. Where a local variable is
assigned right before the check, the assignment and the two returns
turn into a single return of the assigned expression.

Patches 2-36 are generated by the script, with hand fixes to restore
unexpectedly removed comments and to fix the formatting checkpatch.pl
complained about.

The patches are grouped by subsystem instead of split per file. If
you would rather split, merge or drop your part, just let me know
and I will address it in the next version.

All patches are independent and can be applied separately, but for
everyone's convenience, it would be nice if they were merged through
a single tree.

The series is based on next-20260721.

Sang-Heon Jeon (36):
  coccinelle: misc: add cond_return_no_effect.cocci
  drm/amd: remove conditional return with no effect
  drm/radeon: remove conditional return with no effect
  dpll: zl3073x: remove conditional return with no effect
  drm/i915: remove conditional return with no effect
  drm: remove conditional return with no effect
  net: ethernet: remove conditional return with no effect
  net: remove conditional return with no effect
  net: intel: remove conditional return with no effect
  wifi: remove conditional return with no effect
  ipvs: remove conditional return with no effect
  media: remove conditional return with no effect
  ALSA: remove conditional return with no effect
  ASoC: remove conditional return with no effect
  iio: remove conditional return with no effect
  Input: remove conditional return with no effect
  clk: remove conditional return with no effect
  crypto: drivers - remove conditional return with no effect
  dmaengine: qcom_hidma: remove conditional return with no effect
  stm class: remove conditional return with no effect
  RDMA/ocrdma: remove conditional return with no effect
  iommu/s390: remove conditional return with no effect
  dm vdo: remove conditional return with no effect
  pinctrl: mediatek: remove conditional return with no effect
  platform/x86: toshiba_haps: remove conditional return with no effect
  power: supply: pm8916_lbc: remove conditional return with no effect
  RAS/AMD/ATL: remove conditional return with no effect
  regulator: wm831x-isink: remove conditional return with no effect
  rtc: pcf2127: remove conditional return with no effect
  scsi: mpt3sas: remove conditional return with no effect
  thermal/drivers/k3_bandgap: remove conditional return with no effect
  USB: serial: ch341: remove conditional return with no effect
  usb: typec: fusb302: remove conditional return with no effect
  smb: client: remove conditional return with no effect
  cpupower: remove conditional return with no effect
  memblock: remove conditional return with no effect

 drivers/clk/clk-cs2000-cp.c                   |   6 +-
 drivers/clk/clk-lmk04832.c                    |  12 +-
 .../intel/qat/qat_common/adf_gen2_config.c    |   8 +-
 .../marvell/octeontx2/otx2_cpt_mbox_common.c  |   7 +-
 drivers/dma/qcom/hidma_ll.c                   |   6 +-
 drivers/dpll/zl3073x/dpll.c                   |   6 +-
 drivers/dpll/zl3073x/out.c                    |   8 +-
 drivers/gpu/drm/amd/amdgpu/gfx_v7_0.c         |   6 +-
 drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c         |   6 +-
 drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3.c       |   6 +-
 drivers/gpu/drm/amd/amdgpu/sdma_v4_4_2.c      |   6 +-
 drivers/gpu/drm/amd/amdgpu/sdma_v5_0.c        |   6 +-
 drivers/gpu/drm/amd/amdgpu/sdma_v5_2.c        |   6 +-
 drivers/gpu/drm/amd/amdgpu/sdma_v6_0.c        |   6 +-
 drivers/gpu/drm/amd/amdgpu/uvd_v4_2.c         |   6 +-
 drivers/gpu/drm/amd/amdgpu/uvd_v5_0.c         |   6 +-
 drivers/gpu/drm/amd/amdgpu/uvd_v7_0.c         |   6 +-
 drivers/gpu/drm/amd/amdgpu/vce_v4_0.c         |   6 +-
 drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c    |  32 ++---
 drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c    |   6 +-
 drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c     |   6 +-
 .../gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c |   6 +-
 .../gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c   |   6 +-
 .../gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c    |  19 +--
 .../gpu/drm/amd/pm/swsmu/smu11/vangogh_ppt.c  |   7 +-
 .../gpu/drm/amd/pm/swsmu/smu12/renoir_ppt.c   |   7 +-
 .../drm/amd/pm/swsmu/smu13/aldebaran_ppt.c    |   6 +-
 .../gpu/drm/amd/pm/swsmu/smu13/smu_v13_0.c    |  19 +--
 .../drm/amd/pm/swsmu/smu13/smu_v13_0_0_ppt.c  |   6 +-
 .../drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c  |  10 +-
 .../drm/amd/pm/swsmu/smu13/smu_v13_0_7_ppt.c  |   6 +-
 .../gpu/drm/amd/pm/swsmu/smu14/smu_v14_0.c    |  19 +--
 .../drm/amd/pm/swsmu/smu14/smu_v14_0_2_ppt.c  |   6 +-
 .../gpu/drm/amd/pm/swsmu/smu15/smu_v15_0.c    |   9 +-
 .../drm/amd/pm/swsmu/smu15/smu_v15_0_8_ppt.c  |  16 +--
 drivers/gpu/drm/i915/display/intel_hdmi.c     |   7 +-
 drivers/gpu/drm/i915/gvt/gtt.c                |   8 +-
 drivers/gpu/drm/imx/ipuv3/imx-drm-core.c      |   6 +-
 drivers/gpu/drm/nouveau/dispnv50/disp.c       |  14 +-
 .../drm/panel/panel-osd-osd101t2587-53ts.c    |   7 +-
 drivers/gpu/drm/radeon/ci_dpm.c               |   6 +-
 drivers/gpu/drm/radeon/kv_dpm.c               |  30 ++---
 drivers/gpu/drm/radeon/si_dpm.c               |  14 +-
 drivers/gpu/drm/tilcdc/tilcdc_drv.c           |   6 +-
 drivers/hwtracing/stm/core.c                  |   8 +-
 drivers/iio/light/isl29028.c                  |   6 +-
 drivers/iio/light/tsl2583.c                   |  14 +-
 drivers/iio/magnetometer/ak8974.c             |   6 +-
 drivers/infiniband/hw/ocrdma/ocrdma_verbs.c   |   7 +-
 drivers/input/keyboard/pmic8xxx-keypad.c      |   8 +-
 drivers/input/mouse/synaptics_i2c.c           |   6 +-
 drivers/input/rmi4/rmi_smbus.c                |   7 +-
 drivers/iommu/s390-iommu.c                    |   8 +-
 drivers/md/dm-vdo/encodings.c                 |   8 +-
 drivers/media/i2c/mt9p031.c                   |   6 +-
 .../microchip/microchip-sama7g5-isc.c         |   7 +-
 .../media/platform/qcom/iris/iris_resources.c |   6 +-
 .../media/platform/qcom/venus/pm_helpers.c    |   7 +-
 drivers/media/platform/renesas/rcar-csi2.c    |   6 +-
 .../platform/samsung/s3c-camif/camif-core.c   |   7 +-
 drivers/media/usb/dvb-usb-v2/mxl111sf.c       |  12 +-
 drivers/media/usb/gspca/jl2005bcd.c           |   7 +-
 drivers/net/ethernet/amazon/ena/ena_netdev.c  |   6 +-
 .../ethernet/aquantia/atlantic/aq_macsec.c    |   6 +-
 .../ethernet/freescale/dpaa2/dpaa2-switch.c   |   6 +-
 drivers/net/ethernet/freescale/gianfar.c      |   6 +-
 drivers/net/ethernet/intel/i40e/i40e_main.c   |   8 +-
 drivers/net/ethernet/intel/igb/e1000_i210.c   |   6 +-
 drivers/net/ethernet/intel/igc/igc_phy.c      |   6 +-
 .../ethernet/qlogic/netxen/netxen_nic_hw.c    |   7 +-
 .../ethernet/qlogic/qlcnic/qlcnic_83xx_init.c |   6 +-
 drivers/net/ethernet/renesas/rtsn.c           |   7 +-
 drivers/net/phy/microchip_t1.c                |   6 +-
 drivers/net/pse-pd/tps23881.c                 |   6 +-
 drivers/net/wireless/ath/ath6kl/init.c        |   6 +-
 drivers/net/wireless/intel/iwlwifi/mvm/link.c |   6 +-
 .../wireless/realtek/rtlwifi/rtl8821ae/hw.c   |   7 +-
 drivers/net/wireless/realtek/rtw89/mac.c      |   6 +-
 drivers/net/wireless/realtek/rtw89/mac_be.c   |   6 +-
 .../pinctrl/mediatek/pinctrl-mtk-common-v2.c  |   6 +-
 drivers/platform/x86/toshiba_haps.c           |   6 +-
 drivers/power/supply/pm8916_lbc.c             |   8 +-
 drivers/ras/amd/atl/map.c                     |   6 +-
 drivers/regulator/wm831x-isink.c              |   6 +-
 drivers/rtc/rtc-pcf2127.c                     |   7 +-
 drivers/scsi/mpt3sas/mpt3sas_base.c           |   6 +-
 drivers/thermal/k3_bandgap.c                  |   7 +-
 drivers/usb/serial/ch341.c                    |   8 +-
 drivers/usb/typec/tcpm/fusb302.c              |  14 +-
 fs/smb/client/smb1maperror.c                  |   6 +-
 mm/memblock.c                                 |   7 +-
 net/netfilter/ipvs/ip_vs_sync.c               |   7 +-
 .../misc/cond_return_no_effect.cocci          | 121 ++++++++++++++++++
 sound/pci/echoaudio/echoaudio_dsp.c           |   6 +-
 sound/pci/echoaudio/layla24_dsp.c             |   6 +-
 sound/pci/riptide/riptide.c                   |   5 +-
 sound/soc/amd/acp/acp-mach-common.c           |  11 +-
 sound/soc/intel/atom/sst-mfld-platform-pcm.c  |   7 +-
 sound/soc/samsung/smdk_spdif.c                |   8 +-
 sound/soc/sof/intel/hda-dsp.c                 |   6 +-
 sound/usb/mixer_scarlett.c                    |  26 ++--
 tools/power/cpupower/utils/powercap-info.c    |   2 -
 102 files changed, 295 insertions(+), 643 deletions(-)
 create mode 100644 scripts/coccinelle/misc/cond_return_no_effect.cocci

--
2.43.0

[PATCH 26/36] power: supply: pm8916_lbc: remove conditional return with no effect

[Sang-Heon Jeon]

Both branches of the check return the same value, so the check has
no effect. Remove it and return the value directly.

This is the result of running the Coccinelle script from
scripts/coccinelle/misc/cond_return_no_effect.cocci.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
 drivers/power/supply/pm8916_lbc.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/power/supply/pm8916_lbc.c b/drivers/power/supply/pm8916_lbc.c
index cdc4d78c4219..569f3f4b16fe 100644
--- a/drivers/power/supply/pm8916_lbc.c
+++ b/drivers/power/supply/pm8916_lbc.c
@@ -231,11 +231,9 @@ static int pm8916_lbc_charger_probe_dt(struct pm8916_lbc_charger *chg)
 		return ret;
 
 	/* Disable charger timeout. */
-	ret = regmap_write(chg->regmap, chg->reg[LBC_CHGR] + PM8916_LBC_CHGR_TCHG_MAX_EN, 0x00);
-	if (ret)
-		return ret;
-
-	return ret;
+	return regmap_write(chg->regmap,
+			    chg->reg[LBC_CHGR] + PM8916_LBC_CHGR_TCHG_MAX_EN,
+			    0x00);
 }
 
 static const struct power_supply_desc pm8916_lbc_charger_psy_desc = {
-- 
2.43.0

[PATCH 31/36] thermal/drivers/k3_bandgap: remove conditional return with no effect

[Sang-Heon Jeon]

Both branches of the check return the same value, so the check has
no effect. Remove it and return the value directly.

This is the result of running the Coccinelle script from
scripts/coccinelle/misc/cond_return_no_effect.cocci.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
 drivers/thermal/k3_bandgap.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/thermal/k3_bandgap.c b/drivers/thermal/k3_bandgap.c
index 678d6ed711b5..766fab7bcf1b 100644
--- a/drivers/thermal/k3_bandgap.c
+++ b/drivers/thermal/k3_bandgap.c
@@ -141,13 +141,8 @@ static int k3_bgp_read_temp(struct k3_thermal_data *devdata,
 static int k3_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
 {
 	struct k3_thermal_data *data = thermal_zone_device_priv(tz);
-	int ret = 0;
 
-	ret = k3_bgp_read_temp(data, temp);
-	if (ret)
-		return ret;
-
-	return ret;
+	return k3_bgp_read_temp(data, temp);
 }
 
 static const struct thermal_zone_device_ops k3_of_thermal_ops = {
-- 
2.43.0

[PATCH 35/36] cpupower: remove conditional return with no effect

[Sang-Heon Jeon]

Both branches of the check return the same value, so the check has
no effect. Remove it and return the value directly.

This is the result of running the Coccinelle script from
scripts/coccinelle/misc/cond_return_no_effect.cocci.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
---
 tools/power/cpupower/utils/powercap-info.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tools/power/cpupower/utils/powercap-info.c b/tools/power/cpupower/utils/powercap-info.c
index e53033488218..88a5edb76315 100644
--- a/tools/power/cpupower/utils/powercap-info.c
+++ b/tools/power/cpupower/utils/powercap-info.c
@@ -47,8 +47,6 @@ static int powercap_print_one_zone(struct powercap_zone *zone)
 
 	printf("\n");
 
-	if (ret != 0)
-		return ret;
 	return ret;
 }
 
-- 
2.43.0

Re: [PATCH 00/36] treewide: remove conditional returns with no effect

[Jakub Kicinski]

On Fri, 24 Jul 2026 03:45:02 +0900 Sang-Heon Jeon wrote:
> Patch 1 adds a Coccinelle script that matches the pattern, including
> negation and constant-comparison variants. Where a local variable is
> assigned right before the check, the assignment and the two returns
> turn into a single return of the assigned expression.

Huh, I thought we already had such script. Various script children have
been sending such "cleanups" in the past.

> Patches 2-36 are generated by the script, with hand fixes to restore
> unexpectedly removed comments and to fix the formatting checkpatch.pl
> complained about.

Please post patches 4,7,8,9 as a separate series. Since you only CCed
netdev on subset of the series patchwork thinks there are patches
missing and doesn't kick off any CI.

Re: [PATCH 00/36] treewide: remove conditional returns with no effect

[Jani Nikula]

On Fri, 24 Jul 2026, Jakub Kicinski <kuba@kernel.org> wrote:
> On Fri, 24 Jul 2026 03:45:02 +0900 Sang-Heon Jeon wrote:
>> Patch 1 adds a Coccinelle script that matches the pattern, including
>> negation and constant-comparison variants. Where a local variable is
>> assigned right before the check, the assignment and the two returns
>> turn into a single return of the assigned expression.
>
> Huh, I thought we already had such script. Various script children have
> been sending such "cleanups" in the past.

We did, and it was removed, I believe in 1a617a8475e8 ("coccinelle:
misc: remove "complex return code" warnings"), because people just don't
want this constant churn.

It's perfectly fine to have the error case and happy day scenario
separated.


BR,
Jani.


-- 
Jani Nikula, Intel

Re: [PATCH 00/36] treewide: remove conditional returns with no effect

[Sang-Heon Jeon]

Hello,

On Mon, Jul 27, 2026 at 5:30 PM Jani Nikula <jani.nikula@linux.intel.com> wrote:
>
> On Fri, 24 Jul 2026, Jakub Kicinski <kuba@kernel.org> wrote:
> > On Fri, 24 Jul 2026 03:45:02 +0900 Sang-Heon Jeon wrote:
> >> Patch 1 adds a Coccinelle script that matches the pattern, including
> >> negation and constant-comparison variants. Where a local variable is
> >> assigned right before the check, the assignment and the two returns
> >> turn into a single return of the assigned expression.
> >
> > Huh, I thought we already had such script. Various script children have
> > been sending such "cleanups" in the past.
>
> We did, and it was removed, I believe in 1a617a8475e8 ("coccinelle:
> misc: remove "complex return code" warnings"), because people just don't
> want this constant churn.
>
> It's perfectly fine to have the error case and happy day scenario
> separated.

Thanks for sharing the history.

I checked the mailing list. The removed script looks similar to the
new one, but it is different. The removed script reported a
conditional return followed by an explicit return 0, where the error
case and happy day scenario are separated as you mentioned, and Johan
also complained about this 10 years ago.

But the new script only reports when both branches return the same
variable, not the explicit 0. So, I think the new script is close to
the restricted version that Julia mentioned 10 years ago, and it
should be acceptable.

>
> BR,
> Jani.
>
>
> --
> Jani Nikula, Intel

Best Regards,
Sang-Heon Jeon

Re: [PATCH 00/36] treewide: remove conditional returns with no effect

[Jani Nikula]

On Mon, 27 Jul 2026, Sang-Heon Jeon <ekffu200098@gmail.com> wrote:
> Hello,
>
> On Mon, Jul 27, 2026 at 5:30 PM Jani Nikula <jani.nikula@linux.intel.com> wrote:
>>
>> On Fri, 24 Jul 2026, Jakub Kicinski <kuba@kernel.org> wrote:
>> > On Fri, 24 Jul 2026 03:45:02 +0900 Sang-Heon Jeon wrote:
>> >> Patch 1 adds a Coccinelle script that matches the pattern, including
>> >> negation and constant-comparison variants. Where a local variable is
>> >> assigned right before the check, the assignment and the two returns
>> >> turn into a single return of the assigned expression.
>> >
>> > Huh, I thought we already had such script. Various script children have
>> > been sending such "cleanups" in the past.
>>
>> We did, and it was removed, I believe in 1a617a8475e8 ("coccinelle:
>> misc: remove "complex return code" warnings"), because people just don't
>> want this constant churn.
>>
>> It's perfectly fine to have the error case and happy day scenario
>> separated.
>
> Thanks for sharing the history.
>
> I checked the mailing list. The removed script looks similar to the
> new one, but it is different. The removed script reported a
> conditional return followed by an explicit return 0, where the error
> case and happy day scenario are separated as you mentioned, and Johan
> also complained about this 10 years ago.
>
> But the new script only reports when both branches return the same
> variable, not the explicit 0. So, I think the new script is close to
> the restricted version that Julia mentioned 10 years ago, and it
> should be acceptable.

ret === 0 after an if (ret) return.

BR,
Jani.


>
>>
>> BR,
>> Jani.
>>
>>
>> --
>> Jani Nikula, Intel
>
> Best Regards,
> Sang-Heon Jeon

-- 
Jani Nikula, Intel

Re: (subset) [PATCH 00/36] treewide: remove conditional returns with no effect

[Sebastian Reichel]

On Fri, 24 Jul 2026 03:45:02 +0900, Sang-Heon Jeon wrote:
> While reading mm/memblock, I found a conditional return where both
> branches return the same value:
> 
> 	err = do_something();
> 	if (err)
> 		return err;
> 	return err;
> 
> [...]

Applied, thanks!

[26/36] power: supply: pm8916_lbc: remove conditional return with no effect
        commit: b7c8d46411317f135e7791c0eddc56691de63f07

Best regards,
-- 
Sebastian Reichel <sebastian.reichel@collabora.com>

Re: [PATCH 00/36] treewide: remove conditional returns with no effect

[Mark Brown]

[-- Attachment #1: Type: text/plain, Size: 460 bytes --]

On Fri, Jul 24, 2026 at 03:45:02AM +0900, Sang-Heon Jeon wrote:

> All patches are independent and can be applied separately, but for
> everyone's convenience, it would be nice if they were merged through
> a single tree.

Please don't do this, it does not make anything more convenient - it
results in huge CC lists and makes it more difficult to work out who
will actually apply things.  If there's no dependencies just send to
each subsystem independently.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [PATCH 00/36] treewide: remove conditional returns with no effect

[Sang-Heon Jeon]

On Mon, Jul 27, 2026 at 9:12 PM Mark Brown <broonie@kernel.org> wrote:
>
> On Fri, Jul 24, 2026 at 03:45:02AM +0900, Sang-Heon Jeon wrote:
>
> > All patches are independent and can be applied separately, but for
> > everyone's convenience, it would be nice if they were merged through
> > a single tree.
>
> Please don't do this, it does not make anything more convenient - it
> results in huge CC lists and makes it more difficult to work out who
> will actually apply things.  If there's no dependencies just send to
> each subsystem independently.

Thanks for letting me know. I'll keep that in mind. In v2, I will send
the cleanup patches to each subsystem independently.

Best Regards,
Sang-Heon Jeon