[PATCH net-next 00/10] net*: Convert to platform remove callback returning void

[PATCH net-next 00/10] net*: Convert to platform remove callback returning void

[Uwe Kleine-König]

Hello,

this series converts the platform drivers below drivers/net that are not
covered in the two other series converting drivers/net/ethernet and
drivers/net/wireless. I put them all in a single series even though they
are not maintained together. I thought that to be better than sending
them out individually, I hope you agree.

See commit 5c5a7680e67b ("platform: Provide a remove callback that
returns no value") for an extended explanation and the eventual goal.
The TL;DR; is to make it harder for driver authors to leak resources
without noticing.

The first patch is a fix, but I don't think it's worth to add that to
stable, it was broken since v5.7-rc1 and nobody seems to have hit the
problem.

Best regards
Uwe

Uwe Kleine-König (10):
  net: ipa: Don't error out in .remove()
  net: ipa: Convert to platform remove callback returning void
  net: fjes: Convert to platform remove callback returning void
  net: pcs: rzn1-miic: Convert to platform remove callback returning
    void
  net: sfp: Convert to platform remove callback returning void
  net: wan/fsl_ucc_hdlc: Convert to platform remove callback returning
    void
  net: wan/ixp4xx_hss: Convert to platform remove callback returning
    void
  net: wwan: qcom_bam_dmux: Convert to platform remove callback
    returning void
  ieee802154: fakelb: Convert to platform remove callback returning void
  ieee802154: hwsim: Convert to platform remove callback returning void

 drivers/net/fjes/fjes_main.c             |  6 ++----
 drivers/net/ieee802154/fakelb.c          |  5 ++---
 drivers/net/ieee802154/mac802154_hwsim.c |  6 ++----
 drivers/net/ipa/ipa_main.c               | 20 +++++---------------
 drivers/net/pcs/pcs-rzn1-miic.c          |  6 ++----
 drivers/net/phy/sfp.c                    |  6 ++----
 drivers/net/wan/fsl_ucc_hdlc.c           |  6 ++----
 drivers/net/wan/ixp4xx_hss.c             |  5 ++---
 drivers/net/wwan/qcom_bam_dmux.c         |  6 ++----
 9 files changed, 21 insertions(+), 45 deletions(-)

base-commit: eff99d8edbed7918317331ebd1e365d8e955d65e
-- 
2.42.0

[PATCH net-next 08/10] net: wwan: qcom_bam_dmux: Convert to platform remove callback returning void

[Uwe Kleine-König]

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/net/wwan/qcom_bam_dmux.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wwan/qcom_bam_dmux.c b/drivers/net/wwan/qcom_bam_dmux.c
index 17d46f4d2913..26ca719fa0de 100644
--- a/drivers/net/wwan/qcom_bam_dmux.c
+++ b/drivers/net/wwan/qcom_bam_dmux.c
@@ -846,7 +846,7 @@ static int bam_dmux_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int bam_dmux_remove(struct platform_device *pdev)
+static void bam_dmux_remove(struct platform_device *pdev)
 {
 	struct bam_dmux *dmux = platform_get_drvdata(pdev);
 	struct device *dev = dmux->dev;
@@ -877,8 +877,6 @@ static int bam_dmux_remove(struct platform_device *pdev)
 	disable_irq(dmux->pc_irq);
 	bam_dmux_power_off(dmux);
 	bam_dmux_free_skbs(dmux->tx_skbs, DMA_TO_DEVICE);
-
-	return 0;
 }
 
 static const struct dev_pm_ops bam_dmux_pm_ops = {
@@ -893,7 +891,7 @@ MODULE_DEVICE_TABLE(of, bam_dmux_of_match);
 
 static struct platform_driver bam_dmux_driver = {
 	.probe = bam_dmux_probe,
-	.remove = bam_dmux_remove,
+	.remove_new = bam_dmux_remove,
 	.driver = {
 		.name = "bam-dmux",
 		.pm = &bam_dmux_pm_ops,
-- 
2.42.0

Re: [PATCH net-next 08/10] net: wwan: qcom_bam_dmux: Convert to platform remove callback returning void

[Sergey Ryazanov]

On 17.11.2023 11:59, Uwe Kleine-König wrote:
> The .remove() callback for a platform driver returns an int which makes
> many driver authors wrongly assume it's possible to do error handling by
> returning an error code. However the value returned is ignored (apart
> from emitting a warning) and this typically results in resource leaks.
> 
> To improve here there is a quest to make the remove callback return
> void. In the first step of this quest all drivers are converted to
> .remove_new(), which already returns void. Eventually after all drivers
> are converted, .remove_new() will be renamed to .remove().
> 
> Trivially convert this driver from always returning zero in the remove
> callback to the void returning variant.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>