[PATCH 00/15] PCI: Convert to platform remove callback returning void

[PATCH 00/15] PCI: Convert to platform remove callback returning void

[Uwe Kleine-König]

Hello,

this series adapts the platform drivers below drivers/pci to use the
.remove_new() callback. Compared to the traditional .remove() callback
.remove_new() returns no value. This is a good thing because the driver core
doesn't (and cannot) cope for errors during remove. The only effect of a
non-zero return value in .remove() is that the driver core emits a warning. The
device is removed anyhow and an early return from .remove() usually yields a
resource leak.

By changing the remove callback to return void driver authors cannot
reasonably assume any more that there is some kind of cleanup later.

All drivers were easy to convert as they all returned zero in their
remove callback. Only for iproc the conversion wasn't trivial, the other
were converted using coccinelle.

There are no interdependencies between these patches. So even if there
are some concerns for individual patches, I ask you to apply the
remaining set. Then I only have to care for the review feedback of the
refused patches. (Having said that I don't expect any serious objection,
just things like squashing or separating patches, or maybe I picked a
wrong subject prefix.)

Best regards
Uwe

Uwe Kleine-König (15):
  PCI: aardvark: Convert to platform remove callback returning void
  PCI: altera: Convert to platform remove callback returning void
  PCI: altera-msi: Convert to platform remove callback returning void
  PCI: brcmstb: Convert to platform remove callback returning void
  PCI: cadence/j721e: Convert to platform remove callback returning void
  PCI: dwc/*: Convert to platform remove callback returning void
  PCI: hisi-error: Convert to platform remove callback returning void
  PCI: iproc: Convert to platform remove callback returning void
  PCI: mediatek: Convert to platform remove callback returning void
  PCI: mediatek-gen3: Convert to platform remove callback returning void
  PCI: mt7621: Convert to platform remove callback returning void
  PCI: mvebu: Convert to platform remove callback returning void
  PCI: rockchip-host: Convert to platform remove callback returning void
  PCI: tegra: Convert to platform remove callback returning void
  PCI: xgene-msi: Convert to platform remove callback returning void

 drivers/pci/controller/cadence/pci-j721e.c   | 6 ++----
 drivers/pci/controller/dwc/pcie-bt1.c        | 6 ++----
 drivers/pci/controller/dwc/pcie-histb.c      | 6 ++----
 drivers/pci/controller/dwc/pcie-intel-gw.c   | 6 ++----
 drivers/pci/controller/dwc/pcie-qcom-ep.c    | 8 +++-----
 drivers/pci/controller/dwc/pcie-tegra194.c   | 8 +++-----
 drivers/pci/controller/pci-aardvark.c        | 6 ++----
 drivers/pci/controller/pci-mvebu.c           | 6 ++----
 drivers/pci/controller/pci-tegra.c           | 6 ++----
 drivers/pci/controller/pci-xgene-msi.c       | 6 ++----
 drivers/pci/controller/pcie-altera-msi.c     | 5 ++---
 drivers/pci/controller/pcie-altera.c         | 6 ++----
 drivers/pci/controller/pcie-brcmstb.c        | 6 ++----
 drivers/pci/controller/pcie-hisi-error.c     | 6 ++----
 drivers/pci/controller/pcie-iproc-platform.c | 6 +++---
 drivers/pci/controller/pcie-iproc.c          | 4 +---
 drivers/pci/controller/pcie-iproc.h          | 2 +-
 drivers/pci/controller/pcie-mediatek-gen3.c  | 6 ++----
 drivers/pci/controller/pcie-mediatek.c       | 6 ++----
 drivers/pci/controller/pcie-mt7621.c         | 6 ++----
 drivers/pci/controller/pcie-rockchip-host.c  | 6 ++----
 21 files changed, 43 insertions(+), 80 deletions(-)

base-commit: fe15c26ee26efa11741a7b632e9f23b01aca4cc6
-- 
2.39.2

[PATCH 09/15] PCI: mediatek: 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 (mostly) ignored
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.

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/pci/controller/pcie-mediatek.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
index ae5ad05ddc1d..7ee03400961b 100644
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -1134,7 +1134,7 @@ static void mtk_pcie_free_resources(struct mtk_pcie *pcie)
 	pci_free_resource_list(windows);
 }
 
-static int mtk_pcie_remove(struct platform_device *pdev)
+static void mtk_pcie_remove(struct platform_device *pdev)
 {
 	struct mtk_pcie *pcie = platform_get_drvdata(pdev);
 	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
@@ -1146,8 +1146,6 @@ static int mtk_pcie_remove(struct platform_device *pdev)
 	mtk_pcie_irq_teardown(pcie);
 
 	mtk_pcie_put_resources(pcie);
-
-	return 0;
 }
 
 static int mtk_pcie_suspend_noirq(struct device *dev)
@@ -1239,7 +1237,7 @@ MODULE_DEVICE_TABLE(of, mtk_pcie_ids);
 
 static struct platform_driver mtk_pcie_driver = {
 	.probe = mtk_pcie_probe,
-	.remove = mtk_pcie_remove,
+	.remove_new = mtk_pcie_remove,
 	.driver = {
 		.name = "mtk-pcie",
 		.of_match_table = mtk_pcie_ids,
-- 
2.39.2

[PATCH 10/15] PCI: mediatek-gen3: 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 (mostly) ignored
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.

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/pci/controller/pcie-mediatek-gen3.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c
index b8612ce5f4d0..e0e27645fdf4 100644
--- a/drivers/pci/controller/pcie-mediatek-gen3.c
+++ b/drivers/pci/controller/pcie-mediatek-gen3.c
@@ -943,7 +943,7 @@ static int mtk_pcie_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int mtk_pcie_remove(struct platform_device *pdev)
+static void mtk_pcie_remove(struct platform_device *pdev)
 {
 	struct mtk_gen3_pcie *pcie = platform_get_drvdata(pdev);
 	struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
@@ -955,8 +955,6 @@ static int mtk_pcie_remove(struct platform_device *pdev)
 
 	mtk_pcie_irq_teardown(pcie);
 	mtk_pcie_power_down(pcie);
-
-	return 0;
 }
 
 static void mtk_pcie_irq_save(struct mtk_gen3_pcie *pcie)
@@ -1069,7 +1067,7 @@ MODULE_DEVICE_TABLE(of, mtk_pcie_of_match);
 
 static struct platform_driver mtk_pcie_driver = {
 	.probe = mtk_pcie_probe,
-	.remove = mtk_pcie_remove,
+	.remove_new = mtk_pcie_remove,
 	.driver = {
 		.name = "mtk-pcie-gen3",
 		.of_match_table = mtk_pcie_of_match,
-- 
2.39.2

[PATCH 11/15] PCI: mt7621: 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 (mostly) ignored
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.

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/pci/controller/pcie-mt7621.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/controller/pcie-mt7621.c b/drivers/pci/controller/pcie-mt7621.c
index 63a5f4463a9f..a6df50a945d1 100644
--- a/drivers/pci/controller/pcie-mt7621.c
+++ b/drivers/pci/controller/pcie-mt7621.c
@@ -524,15 +524,13 @@ static int mt7621_pcie_probe(struct platform_device *pdev)
 	return err;
 }
 
-static int mt7621_pcie_remove(struct platform_device *pdev)
+static void mt7621_pcie_remove(struct platform_device *pdev)
 {
 	struct mt7621_pcie *pcie = platform_get_drvdata(pdev);
 	struct mt7621_pcie_port *port;
 
 	list_for_each_entry(port, &pcie->ports, list)
 		reset_control_put(port->pcie_rst);
-
-	return 0;
 }
 
 static const struct of_device_id mt7621_pcie_ids[] = {
@@ -543,7 +541,7 @@ MODULE_DEVICE_TABLE(of, mt7621_pcie_ids);
 
 static struct platform_driver mt7621_pcie_driver = {
 	.probe = mt7621_pcie_probe,
-	.remove = mt7621_pcie_remove,
+	.remove_new = mt7621_pcie_remove,
 	.driver = {
 		.name = "mt7621-pci",
 		.of_match_table = mt7621_pcie_ids,
-- 
2.39.2

Re: [PATCH 11/15] PCI: mt7621: Convert to platform remove callback returning void

[Sergio Paracuellos]

On Tue, Mar 21, 2023 at 8:32 PM Uwe Kleine-König
<u.kleine-koenig@pengutronix.de> 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 (mostly) ignored
> 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.
>
> 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/pci/controller/pcie-mt7621.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)

Reviewed-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>

Best regards,
    Sergio Paracuellos

Re: [PATCH 00/15] PCI: Convert to platform remove callback returning void

[Uwe Kleine-König]

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Hello Bjorn,

On Tue, Mar 21, 2023 at 08:31:53PM +0100, Uwe Kleine-König wrote:
> this series adapts the platform drivers below drivers/pci to use the
> .remove_new() callback. Compared to the traditional .remove() callback
> .remove_new() returns no value. This is a good thing because the driver core
> doesn't (and cannot) cope for errors during remove. The only effect of a
> non-zero return value in .remove() is that the driver core emits a warning. The
> device is removed anyhow and an early return from .remove() usually yields a
> resource leak.
> 
> By changing the remove callback to return void driver authors cannot
> reasonably assume any more that there is some kind of cleanup later.
> 
> All drivers were easy to convert as they all returned zero in their
> remove callback. Only for iproc the conversion wasn't trivial, the other
> were converted using coccinelle.
> 
> There are no interdependencies between these patches. So even if there
> are some concerns for individual patches, I ask you to apply the
> remaining set. Then I only have to care for the review feedback of the
> refused patches. (Having said that I don't expect any serious objection,
> just things like squashing or separating patches, or maybe I picked a
> wrong subject prefix.)

These patches wait for application for quite some time now. They apply
just fine to v6.4-rc1 and next/master. Would be great to get them in
during the next merge window and ideally give them some time in next
before.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH 00/15] PCI: Convert to platform remove callback returning void

[Bjorn Helgaas]

On Tue, May 30, 2023 at 04:07:42PM +0200, Uwe Kleine-König wrote:
> Hello Bjorn,
> 
> On Tue, Mar 21, 2023 at 08:31:53PM +0100, Uwe Kleine-König wrote:
> > this series adapts the platform drivers below drivers/pci to use the
> > .remove_new() callback. Compared to the traditional .remove() callback
> > .remove_new() returns no value. This is a good thing because the driver core
> > doesn't (and cannot) cope for errors during remove. The only effect of a
> > non-zero return value in .remove() is that the driver core emits a warning. The
> > device is removed anyhow and an early return from .remove() usually yields a
> > resource leak.
> > 
> > By changing the remove callback to return void driver authors cannot
> > reasonably assume any more that there is some kind of cleanup later.
> > 
> > All drivers were easy to convert as they all returned zero in their
> > remove callback. Only for iproc the conversion wasn't trivial, the other
> > were converted using coccinelle.
> > 
> > There are no interdependencies between these patches. So even if there
> > are some concerns for individual patches, I ask you to apply the
> > remaining set. Then I only have to care for the review feedback of the
> > refused patches. (Having said that I don't expect any serious objection,
> > just things like squashing or separating patches, or maybe I picked a
> > wrong subject prefix.)
> 
> These patches wait for application for quite some time now. They apply
> just fine to v6.4-rc1 and next/master. Would be great to get them in
> during the next merge window and ideally give them some time in next
> before.

Thanks, these seem fine to me, and Lorenzo normally takes care of
drivers/pci/controller/.  Lorenzo, if it's easier to have me apply
them, that's fine, too, just let me know.

The only tweaks I would make would be:

  PCI: j721e: Convert to platform remove callback returning void
  PCI: dwc: Convert to platform remove callback returning void

to match the git history.

Re: [PATCH 00/15] PCI: Convert to platform remove callback returning void

[Uwe Kleine-König]

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Hello,

[dropped Tom Joseph and Joyce Ooi from Cc:, my last mail in this thread
resulted in a bounce for their addresses.]

On Fri, Jun 02, 2023 at 04:37:34PM -0500, Bjorn Helgaas wrote:
> On Tue, May 30, 2023 at 04:07:42PM +0200, Uwe Kleine-König wrote:
> > Hello Bjorn,
> > 
> > On Tue, Mar 21, 2023 at 08:31:53PM +0100, Uwe Kleine-König wrote:
> > > this series adapts the platform drivers below drivers/pci to use the
> > > .remove_new() callback. Compared to the traditional .remove() callback
> > > .remove_new() returns no value. This is a good thing because the driver core
> > > doesn't (and cannot) cope for errors during remove. The only effect of a
> > > non-zero return value in .remove() is that the driver core emits a warning. The
> > > device is removed anyhow and an early return from .remove() usually yields a
> > > resource leak.
> > > 
> > > By changing the remove callback to return void driver authors cannot
> > > reasonably assume any more that there is some kind of cleanup later.
> > > 
> > > All drivers were easy to convert as they all returned zero in their
> > > remove callback. Only for iproc the conversion wasn't trivial, the other
> > > were converted using coccinelle.
> > > 
> > > There are no interdependencies between these patches. So even if there
> > > are some concerns for individual patches, I ask you to apply the
> > > remaining set. Then I only have to care for the review feedback of the
> > > refused patches. (Having said that I don't expect any serious objection,
> > > just things like squashing or separating patches, or maybe I picked a
> > > wrong subject prefix.)
> > 
> > These patches wait for application for quite some time now. They apply
> > just fine to v6.4-rc1 and next/master. Would be great to get them in
> > during the next merge window and ideally give them some time in next
> > before.
> 
> Thanks, these seem fine to me, and Lorenzo normally takes care of
> drivers/pci/controller/.  Lorenzo, if it's easier to have me apply
> them, that's fine, too, just let me know.
> 
> The only tweaks I would make would be:
> 
>   PCI: j721e: Convert to platform remove callback returning void
>   PCI: dwc: Convert to platform remove callback returning void

If it's easier for you (or Lorenzo) I can resend with these tweaks.
Otherwise if these are adapted when applying them, that's fine for me,
too. Just tell me if I should do anything here.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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