[PATCH v5 0/9] driver core: Fix some race conditions

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* [PATCH v5 0/9] driver core: Fix some race conditions
@ 2026-04-06 23:22 ` Douglas Anderson
  2026-04-06 23:23   ` [PATCH v5 8/9] driver core: Replace dev->of_node_reused with dev_of_node_reused() Douglas Anderson
                     ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Douglas Anderson @ 2026-04-06 23:22 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, Danilo Krummrich,
	Alan Stern
  Cc: Alexey Kardashevskiy, Johan Hovold, Eric Dumazet, Leon Romanovsky,
	Christoph Hellwig, Robin Murphy, maz, Alexander Lobakin,
	Saravana Kannan, Douglas Anderson, Andrew Morton, Frank.Li,
	Jason Gunthorpe, alex, alexander.stein, andre.przywara, andrew,
	andrew, andriy.shevchenko, aou, ardb, astewart, bhelgaas, brgl,
	broonie, catalin.marinas, chleroy, davem, david, devicetree,
	dmaengine, driver-core, gbatra, gregory.clement, hkallweit1,
	iommu, jirislaby, joel, joro, kees, kevin.brodsky, kuba, lenb,
	lgirdwood, linux-acpi, linux-arm-kernel, linux-aspeed, linux-cxl,
	linux-kernel, linux-mips, linux-mm, linux-pci, linux-riscv,
	linux-serial, linux-snps-arc, linux-usb, linux, linuxppc-dev,
	m.szyprowski, maddy, mani, miko.lenczewski, mpe, netdev, npiggin,
	osalvador, oupton, pabeni, palmer, peter.ujfalusi, peterz, pjw,
	robh, sebastian.hesselbarth, tglx, tsbogend, vgupta, vkoul, will,
	willy, yangyicong, yeoreum.yun

The main goal of this series is to fix the observed bug talked about
in the first patch ("driver core: Don't let a device probe until it's
ready"). That patch fixes a problem that has been observed in the real
world and could land even if the rest of the patches are found
unacceptable or need to be spun.

That said, during patch review Danilo correctly pointed out that many
of the bitfield accesses in "struct device" are unsafe. I added a
bunch of patches in the series to address each one.

Danilo said he's most worried about "can_match", so I put that one
first. After that, I tried to transition bitfields to flags in reverse
order to when the bitfield was added.

Even if transitioning from bitfields to flags isn't truly needed for
correctness, it seems silly (and wasteful of space in struct device)
to have some in bitfields and some as flags. Thus I didn't spend time
for each bitfield showing that it's truly needed for correctness.

Transition was done semi manually. Presumably someone skilled at
coccinelle could do a better job, but I just used sed in a heavy-
handed manner and then reviewed/fixed the results, undoing anything my
script got wrong. My terrible/ugly script was:

var=can_match
caps="${var^^}"
for f in $(git grep -l "[>\.]${var}[^1-9_a-zA-Z\[]"); do
  echo $f
  sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)->${var} = true/set_bit(DEV_FLAG_${caps}, \&\\1->flags)/" "$f"
  sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)\.${var} = true/dev_set_${caps}(\&\\1)/" "$f"
  sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)->${var} = false/clear_bit(DEV_FLAG_${caps}, \&\\1->flags)/" "$f"
  sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)\.${var} = false/dev_clear_${caps}(\&\\1)/" "$f"
  sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)->${var} = \([^;]*\)/assign_bit(DEV_FLAG_${caps}, \&\\1->flags, \\2)/" "$f"
  sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)\.${var} = \([^;]*\)/dev_assign_${caps}(\&\\1, \\2)/" "$f"
  sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)->${var}\([^1-9_a-zA-Z\[]\)/test_bit(DEV_FLAG_${caps}, \&\\1->flags)\\2/" "$f"
  sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)\.${var}\([^1-9_a-zA-Z\[]\)/dev_${caps}(\&\\1)\\2/" "$f"
done

From v3 to v4, I transitioned to accessor functions with another ugly
sed script. I had git format the old patches, then transformed them
with:

for f in *.patch; do
  echo $f
  sed -i~ -e "s/test_and_set_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags)/dev_test_and_set_\\L\\1(\\2)/" "$f"
  sed -i~ -e "s/test_and_set_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags)/dev_test_and_set_\\L\\1(\\2)/" "$f"
  sed -i~ -e "s/test_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags)/dev_\\L\\1(\\2)/" "$f"
  sed -i~ -e "s/test_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags)/dev_\\L\\1(\\2)/" "$f"
  sed -i~ -e "s/set_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags)/dev_set_\\L\\1(\\2)/" "$f"
  sed -i~ -e "s/set_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags)/dev_set_\\L\\1(\\2)/" "$f"
  sed -i~ -e "s/clear_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags)/dev_clear_\\L\\1(\\2)/" "$f"
  sed -i~ -e "s/clear_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags)/dev_clear_\\L\\1(\\2)/" "$f"
  sed -i~ -e "s/assign_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags, \(.*\))/dev_assign_\\L\\1(\\2, \\3)/" "$f"
  sed -i~ -e "s/assign_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags, \(.*\))/dev_assign_\\L\\1(\\2, \\3)/" "$f"
done

...and then did a few manual touchups for spacing.

I only marked the first patch as a "Fix" since it is the only one
fixing observed problems. Other patches could be considered fixes too
if folks want.

I tested the first patch in the series backported to kernel 6.6 on the
Pixel phone that was experiencing the race. I added extra printouts to
make sure that the problem was hitting / addressed. The rest of the
patches are tested with allmodconfig with arm32, arm64, ppc, and
x86. I boot tested on an arm64 Chromebook running mainline.

Changes in v5:
- ready_to_prove => ready_to_probe typo
- device_lock() while calling dev_set_ready_to_probe()
- Add comment before "can_match = true" from Danilo.
- undef __create_dev_flag_accessors

Changes in v4:
- Use accessor functions for flags

Changes in v3:
- Use a new "flags" bitfield
- Add missing \n in probe error message

Changes in v2:
- Instead of adjusting the ordering, use "ready_to_probe" flag

Douglas Anderson (9):
  driver core: Don't let a device probe until it's ready
  driver core: Replace dev->can_match with dev_can_match()
  driver core: Replace dev->dma_iommu with dev_dma_iommu()
  driver core: Replace dev->dma_skip_sync with dev_dma_skip_sync()
  driver core: Replace dev->dma_ops_bypass with dev_dma_ops_bypass()
  driver core: Replace dev->state_synced with dev_state_synced()
  driver core: Replace dev->dma_coherent with dev_dma_coherent()
  driver core: Replace dev->of_node_reused with dev_of_node_reused()
  driver core: Replace dev->offline + ->offline_disabled with accessors

 arch/arc/mm/dma.c                             |   4 +-
 arch/arm/mach-highbank/highbank.c             |   2 +-
 arch/arm/mach-mvebu/coherency.c               |   2 +-
 arch/arm/mm/dma-mapping-nommu.c               |   4 +-
 arch/arm/mm/dma-mapping.c                     |  28 ++--
 arch/arm64/kernel/cpufeature.c                |   2 +-
 arch/arm64/mm/dma-mapping.c                   |   2 +-
 arch/mips/mm/dma-noncoherent.c                |   2 +-
 arch/powerpc/kernel/dma-iommu.c               |   8 +-
 .../platforms/pseries/hotplug-memory.c        |   4 +-
 arch/riscv/mm/dma-noncoherent.c               |   2 +-
 drivers/acpi/scan.c                           |   2 +-
 drivers/base/core.c                           |  55 +++++---
 drivers/base/cpu.c                            |   4 +-
 drivers/base/dd.c                             |  36 ++++--
 drivers/base/memory.c                         |   2 +-
 drivers/base/pinctrl.c                        |   2 +-
 drivers/base/platform.c                       |   2 +-
 drivers/dma/ti/k3-udma-glue.c                 |   6 +-
 drivers/dma/ti/k3-udma.c                      |   6 +-
 drivers/iommu/dma-iommu.c                     |   9 +-
 drivers/iommu/iommu.c                         |   5 +-
 drivers/net/pcs/pcs-xpcs-plat.c               |   2 +-
 drivers/of/device.c                           |   6 +-
 drivers/pci/of.c                              |   2 +-
 drivers/pci/pwrctrl/core.c                    |   2 +-
 drivers/regulator/bq257xx-regulator.c         |   2 +-
 drivers/regulator/rk808-regulator.c           |   2 +-
 drivers/tty/serial/serial_base_bus.c          |   2 +-
 drivers/usb/gadget/udc/aspeed-vhub/dev.c      |   2 +-
 include/linux/device.h                        | 122 ++++++++++++------
 include/linux/dma-map-ops.h                   |   6 +-
 include/linux/dma-mapping.h                   |   2 +-
 include/linux/iommu-dma.h                     |   3 +-
 kernel/cpu.c                                  |   4 +-
 kernel/dma/mapping.c                          |  12 +-
 mm/hmm.c                                      |   2 +-
 37 files changed, 218 insertions(+), 142 deletions(-)

-- 
2.53.0.1213.gd9a14994de-goog


^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v5 8/9] driver core: Replace dev->of_node_reused with dev_of_node_reused()
  2026-04-06 23:22 ` [PATCH v5 0/9] driver core: Fix some race conditions Douglas Anderson
@ 2026-04-06 23:23   ` Douglas Anderson
  2026-04-07  7:27     ` Manivannan Sadhasivam
  2026-04-07  9:07     ` Johan Hovold
  2026-04-07  8:57   ` [PATCH v5 0/9] driver core: Fix some race conditions Marek Szyprowski
  2026-04-07 22:58   ` Danilo Krummrich
  2 siblings, 2 replies; 6+ messages in thread
From: Douglas Anderson @ 2026-04-06 23:23 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J . Wysocki, Danilo Krummrich,
	Alan Stern
  Cc: Alexey Kardashevskiy, Johan Hovold, Eric Dumazet, Leon Romanovsky,
	Christoph Hellwig, Robin Murphy, maz, Alexander Lobakin,
	Saravana Kannan, Douglas Anderson, Mark Brown, alexander.stein,
	andrew, andrew, andriy.shevchenko, astewart, bhelgaas, brgl,
	davem, devicetree, driver-core, hkallweit1, jirislaby, joel, kees,
	kuba, lgirdwood, linux-arm-kernel, linux-aspeed, linux-kernel,
	linux-pci, linux-serial, linux-usb, linux, mani, netdev, pabeni,
	robh

In C, bitfields are not necessarily safe to modify from multiple
threads without locking. Switch "of_node_reused" over to the "flags"
field so modifications are safe.

Cc: Johan Hovold <johan@kernel.org>
Acked-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
Not fixing any known bugs; problem is theoretical and found by code
inspection. Change is done somewhat manually and only lightly tested
(mostly compile-time tested).

(no changes since v4)

Changes in v4:
- Use accessor functions for flags

Changes in v3:
- New

 drivers/base/core.c                      | 2 +-
 drivers/base/pinctrl.c                   | 2 +-
 drivers/base/platform.c                  | 2 +-
 drivers/net/pcs/pcs-xpcs-plat.c          | 2 +-
 drivers/of/device.c                      | 6 +++---
 drivers/pci/of.c                         | 2 +-
 drivers/pci/pwrctrl/core.c               | 2 +-
 drivers/regulator/bq257xx-regulator.c    | 2 +-
 drivers/regulator/rk808-regulator.c      | 2 +-
 drivers/tty/serial/serial_base_bus.c     | 2 +-
 drivers/usb/gadget/udc/aspeed-vhub/dev.c | 2 +-
 include/linux/device.h                   | 7 ++++---
 12 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 8a83d7c93361..30825bf83234 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -5283,7 +5283,7 @@ void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
 {
 	of_node_put(dev->of_node);
 	dev->of_node = of_node_get(dev2->of_node);
-	dev->of_node_reused = true;
+	dev_set_of_node_reused(dev);
 }
 EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
 
diff --git a/drivers/base/pinctrl.c b/drivers/base/pinctrl.c
index 6e250272c843..0bbc83231234 100644
--- a/drivers/base/pinctrl.c
+++ b/drivers/base/pinctrl.c
@@ -24,7 +24,7 @@ int pinctrl_bind_pins(struct device *dev)
 {
 	int ret;
 
-	if (dev->of_node_reused)
+	if (dev_of_node_reused(dev))
 		return 0;
 
 	dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL);
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index d44591d52e36..199e6fb25770 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -856,7 +856,7 @@ struct platform_device *platform_device_register_full(
 	pdev->dev.parent = pdevinfo->parent;
 	pdev->dev.fwnode = pdevinfo->fwnode;
 	pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
-	pdev->dev.of_node_reused = pdevinfo->of_node_reused;
+	dev_assign_of_node_reused(&pdev->dev, pdevinfo->of_node_reused);
 
 	if (pdevinfo->dma_mask) {
 		pdev->platform_dma_mask = pdevinfo->dma_mask;
diff --git a/drivers/net/pcs/pcs-xpcs-plat.c b/drivers/net/pcs/pcs-xpcs-plat.c
index b8c48f9effbf..f4b1b8246ce9 100644
--- a/drivers/net/pcs/pcs-xpcs-plat.c
+++ b/drivers/net/pcs/pcs-xpcs-plat.c
@@ -349,7 +349,7 @@ static int xpcs_plat_init_dev(struct dw_xpcs_plat *pxpcs)
 	 * up later. Make sure DD-core is aware of the OF-node being re-used.
 	 */
 	device_set_node(&mdiodev->dev, fwnode_handle_get(dev_fwnode(dev)));
-	mdiodev->dev.of_node_reused = true;
+	dev_set_of_node_reused(&mdiodev->dev);
 
 	/* Pass the data further so the DW XPCS driver core could use it */
 	mdiodev->dev.platform_data = (void *)device_get_match_data(dev);
diff --git a/drivers/of/device.c b/drivers/of/device.c
index f7e75e527667..be4e1584e0af 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -26,7 +26,7 @@
 const struct of_device_id *of_match_device(const struct of_device_id *matches,
 					   const struct device *dev)
 {
-	if (!matches || !dev->of_node || dev->of_node_reused)
+	if (!matches || !dev->of_node || dev_of_node_reused(dev))
 		return NULL;
 	return of_match_node(matches, dev->of_node);
 }
@@ -192,7 +192,7 @@ ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
 {
 	ssize_t sl;
 
-	if (!dev || !dev->of_node || dev->of_node_reused)
+	if (!dev || !dev->of_node || dev_of_node_reused(dev))
 		return -ENODEV;
 
 	sl = of_modalias(dev->of_node, str, len - 2);
@@ -254,7 +254,7 @@ int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *
 {
 	int sl;
 
-	if ((!dev) || (!dev->of_node) || dev->of_node_reused)
+	if ((!dev) || (!dev->of_node) || dev_of_node_reused(dev))
 		return -ENODEV;
 
 	/* Devicetree modalias is tricky, we add it in 2 steps */
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 9f8eb5df279e..1f9b669abdb0 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -38,7 +38,7 @@ int pci_set_of_node(struct pci_dev *dev)
 	struct device *pdev __free(put_device) =
 		bus_find_device_by_of_node(&platform_bus_type, node);
 	if (pdev)
-		dev->bus->dev.of_node_reused = true;
+		dev_set_of_node_reused(&dev->bus->dev);
 
 	device_set_node(&dev->dev, of_fwnode_handle(no_free_ptr(node)));
 	return 0;
diff --git a/drivers/pci/pwrctrl/core.c b/drivers/pci/pwrctrl/core.c
index 7754baed67f2..72963a92362a 100644
--- a/drivers/pci/pwrctrl/core.c
+++ b/drivers/pci/pwrctrl/core.c
@@ -39,7 +39,7 @@ static int pci_pwrctrl_notify(struct notifier_block *nb, unsigned long action,
 		 * If we got here then the PCI device is the second after the
 		 * power control platform device. Mark its OF node as reused.
 		 */
-		dev->of_node_reused = true;
+		dev_set_of_node_reused(dev);
 		break;
 	}
 
diff --git a/drivers/regulator/bq257xx-regulator.c b/drivers/regulator/bq257xx-regulator.c
index dab8f1ab4450..40e0f1a7ae81 100644
--- a/drivers/regulator/bq257xx-regulator.c
+++ b/drivers/regulator/bq257xx-regulator.c
@@ -143,7 +143,7 @@ static int bq257xx_regulator_probe(struct platform_device *pdev)
 	struct regulator_config cfg = {};
 
 	pdev->dev.of_node = pdev->dev.parent->of_node;
-	pdev->dev.of_node_reused = true;
+	dev_set_of_node_reused(&pdev->dev);
 
 	pdata = devm_kzalloc(&pdev->dev, sizeof(struct bq257xx_reg_data), GFP_KERNEL);
 	if (!pdata)
diff --git a/drivers/regulator/rk808-regulator.c b/drivers/regulator/rk808-regulator.c
index e66408f23bb6..8297d31cde9f 100644
--- a/drivers/regulator/rk808-regulator.c
+++ b/drivers/regulator/rk808-regulator.c
@@ -2115,7 +2115,7 @@ static int rk808_regulator_probe(struct platform_device *pdev)
 	int ret, i, nregulators;
 
 	pdev->dev.of_node = pdev->dev.parent->of_node;
-	pdev->dev.of_node_reused = true;
+	dev_set_of_node_reused(&pdev->dev);
 
 	regmap = dev_get_regmap(pdev->dev.parent, NULL);
 	if (!regmap)
diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c
index a12935f6b992..5f23284a8778 100644
--- a/drivers/tty/serial/serial_base_bus.c
+++ b/drivers/tty/serial/serial_base_bus.c
@@ -74,7 +74,7 @@ static int serial_base_device_init(struct uart_port *port,
 	dev->parent = parent_dev;
 	dev->bus = &serial_base_bus_type;
 	dev->release = release;
-	dev->of_node_reused = true;
+	dev_set_of_node_reused(dev);
 
 	device_set_node(dev, fwnode_handle_get(dev_fwnode(parent_dev)));
 
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/dev.c b/drivers/usb/gadget/udc/aspeed-vhub/dev.c
index 2ecd049dacc2..8b9449d16324 100644
--- a/drivers/usb/gadget/udc/aspeed-vhub/dev.c
+++ b/drivers/usb/gadget/udc/aspeed-vhub/dev.c
@@ -593,7 +593,7 @@ int ast_vhub_init_dev(struct ast_vhub *vhub, unsigned int idx)
 		d->gadget.max_speed = USB_SPEED_HIGH;
 	d->gadget.speed = USB_SPEED_UNKNOWN;
 	d->gadget.dev.of_node = vhub->pdev->dev.of_node;
-	d->gadget.dev.of_node_reused = true;
+	dev_set_of_node_reused(&d->gadget.dev);
 
 	rc = usb_add_gadget_udc(d->port_dev, &d->gadget);
 	if (rc != 0)
diff --git a/include/linux/device.h b/include/linux/device.h
index 5b0fb6ad4c72..a79865a212e9 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -483,6 +483,8 @@ struct device_physical_location {
  *		driver/bus sync_state() callback.
  * @DEV_FLAG_DMA_COHERENT: This particular device is dma coherent, even if the
  *		architecture supports non-coherent devices.
+ * @DEV_FLAG_OF_NODE_REUSED: Set if the device-tree node is shared with an
+ *		ancestor device.
  */
 enum struct_device_flags {
 	DEV_FLAG_READY_TO_PROBE = 0,
@@ -492,6 +494,7 @@ enum struct_device_flags {
 	DEV_FLAG_DMA_OPS_BYPASS = 4,
 	DEV_FLAG_STATE_SYNCED = 5,
 	DEV_FLAG_DMA_COHERENT = 6,
+	DEV_FLAG_OF_NODE_REUSED = 7,
 
 	DEV_FLAG_COUNT
 };
@@ -573,8 +576,6 @@ enum struct_device_flags {
  *
  * @offline_disabled: If set, the device is permanently online.
  * @offline:	Set after successful invocation of bus type's .offline().
- * @of_node_reused: Set if the device-tree node is shared with an ancestor
- *              device.
  * @flags:	DEV_FLAG_XXX flags. Use atomic bitfield operations to modify.
  *
  * At the lowest level, every device in a Linux system is represented by an
@@ -681,7 +682,6 @@ struct device {
 
 	bool			offline_disabled:1;
 	bool			offline:1;
-	bool			of_node_reused:1;
 
 	DECLARE_BITMAP(flags, DEV_FLAG_COUNT);
 };
@@ -715,6 +715,7 @@ __create_dev_flag_accessors(dma_skip_sync, DEV_FLAG_DMA_SKIP_SYNC);
 __create_dev_flag_accessors(dma_ops_bypass, DEV_FLAG_DMA_OPS_BYPASS);
 __create_dev_flag_accessors(state_synced, DEV_FLAG_STATE_SYNCED);
 __create_dev_flag_accessors(dma_coherent, DEV_FLAG_DMA_COHERENT);
+__create_dev_flag_accessors(of_node_reused, DEV_FLAG_OF_NODE_REUSED);
 
 #undef __create_dev_flag_accessors
 
-- 
2.53.0.1213.gd9a14994de-goog


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v5 8/9] driver core: Replace dev->of_node_reused with dev_of_node_reused()
  2026-04-06 23:23   ` [PATCH v5 8/9] driver core: Replace dev->of_node_reused with dev_of_node_reused() Douglas Anderson
@ 2026-04-07  7:27     ` Manivannan Sadhasivam
  2026-04-07  9:07     ` Johan Hovold
  1 sibling, 0 replies; 6+ messages in thread
From: Manivannan Sadhasivam @ 2026-04-07  7:27 UTC (permalink / raw)
  To: Douglas Anderson
  Cc: Greg Kroah-Hartman, Rafael J . Wysocki, Danilo Krummrich,
	Alan Stern, Alexey Kardashevskiy, Johan Hovold, Eric Dumazet,
	Leon Romanovsky, Christoph Hellwig, Robin Murphy, maz,
	Alexander Lobakin, Saravana Kannan, Mark Brown, alexander.stein,
	andrew, andrew, andriy.shevchenko, astewart, bhelgaas, brgl,
	davem, devicetree, driver-core, hkallweit1, jirislaby, joel, kees,
	kuba, lgirdwood, linux-arm-kernel, linux-aspeed, linux-kernel,
	linux-pci, linux-serial, linux-usb, linux, netdev, pabeni, robh

On Mon, Apr 06, 2026 at 04:23:01PM -0700, Douglas Anderson wrote:
> In C, bitfields are not necessarily safe to modify from multiple
> threads without locking. Switch "of_node_reused" over to the "flags"
> field so modifications are safe.
> 
> Cc: Johan Hovold <johan@kernel.org>
> Acked-by: Mark Brown <broonie@kernel.org>
> Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
> Reviewed-by: Danilo Krummrich <dakr@kernel.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Acked-by: Manivannan Sadhasivam <mani@kernel.org> # PCI_PWRCTRL

- Mani

> ---
> Not fixing any known bugs; problem is theoretical and found by code
> inspection. Change is done somewhat manually and only lightly tested
> (mostly compile-time tested).
> 
> (no changes since v4)
> 
> Changes in v4:
> - Use accessor functions for flags
> 
> Changes in v3:
> - New
> 
>  drivers/base/core.c                      | 2 +-
>  drivers/base/pinctrl.c                   | 2 +-
>  drivers/base/platform.c                  | 2 +-
>  drivers/net/pcs/pcs-xpcs-plat.c          | 2 +-
>  drivers/of/device.c                      | 6 +++---
>  drivers/pci/of.c                         | 2 +-
>  drivers/pci/pwrctrl/core.c               | 2 +-
>  drivers/regulator/bq257xx-regulator.c    | 2 +-
>  drivers/regulator/rk808-regulator.c      | 2 +-
>  drivers/tty/serial/serial_base_bus.c     | 2 +-
>  drivers/usb/gadget/udc/aspeed-vhub/dev.c | 2 +-
>  include/linux/device.h                   | 7 ++++---
>  12 files changed, 17 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 8a83d7c93361..30825bf83234 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -5283,7 +5283,7 @@ void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
>  {
>  	of_node_put(dev->of_node);
>  	dev->of_node = of_node_get(dev2->of_node);
> -	dev->of_node_reused = true;
> +	dev_set_of_node_reused(dev);
>  }
>  EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
>  
> diff --git a/drivers/base/pinctrl.c b/drivers/base/pinctrl.c
> index 6e250272c843..0bbc83231234 100644
> --- a/drivers/base/pinctrl.c
> +++ b/drivers/base/pinctrl.c
> @@ -24,7 +24,7 @@ int pinctrl_bind_pins(struct device *dev)
>  {
>  	int ret;
>  
> -	if (dev->of_node_reused)
> +	if (dev_of_node_reused(dev))
>  		return 0;
>  
>  	dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL);
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index d44591d52e36..199e6fb25770 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -856,7 +856,7 @@ struct platform_device *platform_device_register_full(
>  	pdev->dev.parent = pdevinfo->parent;
>  	pdev->dev.fwnode = pdevinfo->fwnode;
>  	pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
> -	pdev->dev.of_node_reused = pdevinfo->of_node_reused;
> +	dev_assign_of_node_reused(&pdev->dev, pdevinfo->of_node_reused);
>  
>  	if (pdevinfo->dma_mask) {
>  		pdev->platform_dma_mask = pdevinfo->dma_mask;
> diff --git a/drivers/net/pcs/pcs-xpcs-plat.c b/drivers/net/pcs/pcs-xpcs-plat.c
> index b8c48f9effbf..f4b1b8246ce9 100644
> --- a/drivers/net/pcs/pcs-xpcs-plat.c
> +++ b/drivers/net/pcs/pcs-xpcs-plat.c
> @@ -349,7 +349,7 @@ static int xpcs_plat_init_dev(struct dw_xpcs_plat *pxpcs)
>  	 * up later. Make sure DD-core is aware of the OF-node being re-used.
>  	 */
>  	device_set_node(&mdiodev->dev, fwnode_handle_get(dev_fwnode(dev)));
> -	mdiodev->dev.of_node_reused = true;
> +	dev_set_of_node_reused(&mdiodev->dev);
>  
>  	/* Pass the data further so the DW XPCS driver core could use it */
>  	mdiodev->dev.platform_data = (void *)device_get_match_data(dev);
> diff --git a/drivers/of/device.c b/drivers/of/device.c
> index f7e75e527667..be4e1584e0af 100644
> --- a/drivers/of/device.c
> +++ b/drivers/of/device.c
> @@ -26,7 +26,7 @@
>  const struct of_device_id *of_match_device(const struct of_device_id *matches,
>  					   const struct device *dev)
>  {
> -	if (!matches || !dev->of_node || dev->of_node_reused)
> +	if (!matches || !dev->of_node || dev_of_node_reused(dev))
>  		return NULL;
>  	return of_match_node(matches, dev->of_node);
>  }
> @@ -192,7 +192,7 @@ ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
>  {
>  	ssize_t sl;
>  
> -	if (!dev || !dev->of_node || dev->of_node_reused)
> +	if (!dev || !dev->of_node || dev_of_node_reused(dev))
>  		return -ENODEV;
>  
>  	sl = of_modalias(dev->of_node, str, len - 2);
> @@ -254,7 +254,7 @@ int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *
>  {
>  	int sl;
>  
> -	if ((!dev) || (!dev->of_node) || dev->of_node_reused)
> +	if ((!dev) || (!dev->of_node) || dev_of_node_reused(dev))
>  		return -ENODEV;
>  
>  	/* Devicetree modalias is tricky, we add it in 2 steps */
> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index 9f8eb5df279e..1f9b669abdb0 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -38,7 +38,7 @@ int pci_set_of_node(struct pci_dev *dev)
>  	struct device *pdev __free(put_device) =
>  		bus_find_device_by_of_node(&platform_bus_type, node);
>  	if (pdev)
> -		dev->bus->dev.of_node_reused = true;
> +		dev_set_of_node_reused(&dev->bus->dev);
>  
>  	device_set_node(&dev->dev, of_fwnode_handle(no_free_ptr(node)));
>  	return 0;
> diff --git a/drivers/pci/pwrctrl/core.c b/drivers/pci/pwrctrl/core.c
> index 7754baed67f2..72963a92362a 100644
> --- a/drivers/pci/pwrctrl/core.c
> +++ b/drivers/pci/pwrctrl/core.c
> @@ -39,7 +39,7 @@ static int pci_pwrctrl_notify(struct notifier_block *nb, unsigned long action,
>  		 * If we got here then the PCI device is the second after the
>  		 * power control platform device. Mark its OF node as reused.
>  		 */
> -		dev->of_node_reused = true;
> +		dev_set_of_node_reused(dev);
>  		break;
>  	}
>  
> diff --git a/drivers/regulator/bq257xx-regulator.c b/drivers/regulator/bq257xx-regulator.c
> index dab8f1ab4450..40e0f1a7ae81 100644
> --- a/drivers/regulator/bq257xx-regulator.c
> +++ b/drivers/regulator/bq257xx-regulator.c
> @@ -143,7 +143,7 @@ static int bq257xx_regulator_probe(struct platform_device *pdev)
>  	struct regulator_config cfg = {};
>  
>  	pdev->dev.of_node = pdev->dev.parent->of_node;
> -	pdev->dev.of_node_reused = true;
> +	dev_set_of_node_reused(&pdev->dev);
>  
>  	pdata = devm_kzalloc(&pdev->dev, sizeof(struct bq257xx_reg_data), GFP_KERNEL);
>  	if (!pdata)
> diff --git a/drivers/regulator/rk808-regulator.c b/drivers/regulator/rk808-regulator.c
> index e66408f23bb6..8297d31cde9f 100644
> --- a/drivers/regulator/rk808-regulator.c
> +++ b/drivers/regulator/rk808-regulator.c
> @@ -2115,7 +2115,7 @@ static int rk808_regulator_probe(struct platform_device *pdev)
>  	int ret, i, nregulators;
>  
>  	pdev->dev.of_node = pdev->dev.parent->of_node;
> -	pdev->dev.of_node_reused = true;
> +	dev_set_of_node_reused(&pdev->dev);
>  
>  	regmap = dev_get_regmap(pdev->dev.parent, NULL);
>  	if (!regmap)
> diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c
> index a12935f6b992..5f23284a8778 100644
> --- a/drivers/tty/serial/serial_base_bus.c
> +++ b/drivers/tty/serial/serial_base_bus.c
> @@ -74,7 +74,7 @@ static int serial_base_device_init(struct uart_port *port,
>  	dev->parent = parent_dev;
>  	dev->bus = &serial_base_bus_type;
>  	dev->release = release;
> -	dev->of_node_reused = true;
> +	dev_set_of_node_reused(dev);
>  
>  	device_set_node(dev, fwnode_handle_get(dev_fwnode(parent_dev)));
>  
> diff --git a/drivers/usb/gadget/udc/aspeed-vhub/dev.c b/drivers/usb/gadget/udc/aspeed-vhub/dev.c
> index 2ecd049dacc2..8b9449d16324 100644
> --- a/drivers/usb/gadget/udc/aspeed-vhub/dev.c
> +++ b/drivers/usb/gadget/udc/aspeed-vhub/dev.c
> @@ -593,7 +593,7 @@ int ast_vhub_init_dev(struct ast_vhub *vhub, unsigned int idx)
>  		d->gadget.max_speed = USB_SPEED_HIGH;
>  	d->gadget.speed = USB_SPEED_UNKNOWN;
>  	d->gadget.dev.of_node = vhub->pdev->dev.of_node;
> -	d->gadget.dev.of_node_reused = true;
> +	dev_set_of_node_reused(&d->gadget.dev);
>  
>  	rc = usb_add_gadget_udc(d->port_dev, &d->gadget);
>  	if (rc != 0)
> diff --git a/include/linux/device.h b/include/linux/device.h
> index 5b0fb6ad4c72..a79865a212e9 100644
> --- a/include/linux/device.h
> +++ b/include/linux/device.h
> @@ -483,6 +483,8 @@ struct device_physical_location {
>   *		driver/bus sync_state() callback.
>   * @DEV_FLAG_DMA_COHERENT: This particular device is dma coherent, even if the
>   *		architecture supports non-coherent devices.
> + * @DEV_FLAG_OF_NODE_REUSED: Set if the device-tree node is shared with an
> + *		ancestor device.
>   */
>  enum struct_device_flags {
>  	DEV_FLAG_READY_TO_PROBE = 0,
> @@ -492,6 +494,7 @@ enum struct_device_flags {
>  	DEV_FLAG_DMA_OPS_BYPASS = 4,
>  	DEV_FLAG_STATE_SYNCED = 5,
>  	DEV_FLAG_DMA_COHERENT = 6,
> +	DEV_FLAG_OF_NODE_REUSED = 7,
>  
>  	DEV_FLAG_COUNT
>  };
> @@ -573,8 +576,6 @@ enum struct_device_flags {
>   *
>   * @offline_disabled: If set, the device is permanently online.
>   * @offline:	Set after successful invocation of bus type's .offline().
> - * @of_node_reused: Set if the device-tree node is shared with an ancestor
> - *              device.
>   * @flags:	DEV_FLAG_XXX flags. Use atomic bitfield operations to modify.
>   *
>   * At the lowest level, every device in a Linux system is represented by an
> @@ -681,7 +682,6 @@ struct device {
>  
>  	bool			offline_disabled:1;
>  	bool			offline:1;
> -	bool			of_node_reused:1;
>  
>  	DECLARE_BITMAP(flags, DEV_FLAG_COUNT);
>  };
> @@ -715,6 +715,7 @@ __create_dev_flag_accessors(dma_skip_sync, DEV_FLAG_DMA_SKIP_SYNC);
>  __create_dev_flag_accessors(dma_ops_bypass, DEV_FLAG_DMA_OPS_BYPASS);
>  __create_dev_flag_accessors(state_synced, DEV_FLAG_STATE_SYNCED);
>  __create_dev_flag_accessors(dma_coherent, DEV_FLAG_DMA_COHERENT);
> +__create_dev_flag_accessors(of_node_reused, DEV_FLAG_OF_NODE_REUSED);
>  
>  #undef __create_dev_flag_accessors
>  
> -- 
> 2.53.0.1213.gd9a14994de-goog
> 

-- 
மணிவண்ணன் சதாசிவம்

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v5 8/9] driver core: Replace dev->of_node_reused with dev_of_node_reused()
  2026-04-06 23:23   ` [PATCH v5 8/9] driver core: Replace dev->of_node_reused with dev_of_node_reused() Douglas Anderson
  2026-04-07  7:27     ` Manivannan Sadhasivam
@ 2026-04-07  9:07     ` Johan Hovold
  1 sibling, 0 replies; 6+ messages in thread
From: Johan Hovold @ 2026-04-07  9:07 UTC (permalink / raw)
  To: Douglas Anderson
  Cc: Greg Kroah-Hartman, Rafael J . Wysocki, Danilo Krummrich,
	Alan Stern, Alexey Kardashevskiy, Eric Dumazet, Leon Romanovsky,
	Christoph Hellwig, Robin Murphy, maz, Alexander Lobakin,
	Saravana Kannan, Mark Brown, alexander.stein, andrew, andrew,
	andriy.shevchenko, astewart, bhelgaas, brgl, davem, devicetree,
	driver-core, hkallweit1, jirislaby, joel, kees, kuba, lgirdwood,
	linux-arm-kernel, linux-aspeed, linux-kernel, linux-pci,
	linux-serial, linux-usb, linux, mani, netdev, pabeni, robh

On Mon, Apr 06, 2026 at 04:23:01PM -0700, Doug Anderson wrote:
> In C, bitfields are not necessarily safe to modify from multiple
> threads without locking. Switch "of_node_reused" over to the "flags"
> field so modifications are safe.

This flag is only set before registering a device with driver core so
there is no issue using the existing bitfield here (with the caveat that
PCI pwrctrl may have gotten that wrong). I haven't checked the other
flags, but I assume most of them work the same way.

But apart from the commit message being misleading, switching to using
atomic ops and accessors for consistency is fine.

> Cc: Johan Hovold <johan@kernel.org>
> Acked-by: Mark Brown <broonie@kernel.org>
> Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
> Reviewed-by: Danilo Krummrich <dakr@kernel.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> Not fixing any known bugs; problem is theoretical and found by code
> inspection. Change is done somewhat manually and only lightly tested
> (mostly compile-time tested).
 
> diff --git a/drivers/regulator/bq257xx-regulator.c b/drivers/regulator/bq257xx-regulator.c
> index dab8f1ab4450..40e0f1a7ae81 100644
> --- a/drivers/regulator/bq257xx-regulator.c
> +++ b/drivers/regulator/bq257xx-regulator.c
> @@ -143,7 +143,7 @@ static int bq257xx_regulator_probe(struct platform_device *pdev)
>  	struct regulator_config cfg = {};
>  
>  	pdev->dev.of_node = pdev->dev.parent->of_node;
> -	pdev->dev.of_node_reused = true;
> +	dev_set_of_node_reused(&pdev->dev);
>  
>  	pdata = devm_kzalloc(&pdev->dev, sizeof(struct bq257xx_reg_data), GFP_KERNEL);
>  	if (!pdata)
> diff --git a/drivers/regulator/rk808-regulator.c b/drivers/regulator/rk808-regulator.c
> index e66408f23bb6..8297d31cde9f 100644
> --- a/drivers/regulator/rk808-regulator.c
> +++ b/drivers/regulator/rk808-regulator.c
> @@ -2115,7 +2115,7 @@ static int rk808_regulator_probe(struct platform_device *pdev)
>  	int ret, i, nregulators;
>  
>  	pdev->dev.of_node = pdev->dev.parent->of_node;
> -	pdev->dev.of_node_reused = true;
> +	dev_set_of_node_reused(&pdev->dev);
>  
>  	regmap = dev_get_regmap(pdev->dev.parent, NULL);
>  	if (!regmap)

These two uses are broken currently though and should be using
device_set_of_node_from_dev() so that an extra reference is taken to
balance the one dropped by the platform bus code.

I'll send two fixes to Mark, any merge conflict should be trivial to
fixup.

Reviewed-by: Johan Hovold <johan@kernel.org>

Johan

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v5 0/9] driver core: Fix some race conditions
  2026-04-06 23:22 ` [PATCH v5 0/9] driver core: Fix some race conditions Douglas Anderson
  2026-04-06 23:23   ` [PATCH v5 8/9] driver core: Replace dev->of_node_reused with dev_of_node_reused() Douglas Anderson
@ 2026-04-07  8:57   ` Marek Szyprowski
  2026-04-07 22:58   ` Danilo Krummrich
  2 siblings, 0 replies; 6+ messages in thread
From: Marek Szyprowski @ 2026-04-07  8:57 UTC (permalink / raw)
  To: Douglas Anderson, Greg Kroah-Hartman, Rafael J . Wysocki,
	Danilo Krummrich, Alan Stern
  Cc: Leon Romanovsky, Christoph Hellwig, Robin Murphy, driver-core,
	iommu, linux-acpi, linux-arm-kernel, linux-kernel, linux-mm,
	linux-pci, linux-usb, linux


On 07.04.2026 01:22, Douglas Anderson wrote:
> The main goal of this series is to fix the observed bug talked about
> in the first patch ("driver core: Don't let a device probe until it's
> ready"). That patch fixes a problem that has been observed in the real
> world and could land even if the rest of the patches are found
> unacceptable or need to be spun.
>
> That said, during patch review Danilo correctly pointed out that many
> of the bitfield accesses in "struct device" are unsafe. I added a
> bunch of patches in the series to address each one.
>
> Danilo said he's most worried about "can_match", so I put that one
> first. After that, I tried to transition bitfields to flags in reverse
> order to when the bitfield was added.
>
> Even if transitioning from bitfields to flags isn't truly needed for
> correctness, it seems silly (and wasteful of space in struct device)
> to have some in bitfields and some as flags. Thus I didn't spend time
> for each bitfield showing that it's truly needed for correctness.
>
> Transition was done semi manually. Presumably someone skilled at
> coccinelle could do a better job, but I just used sed in a heavy-
> handed manner and then reviewed/fixed the results, undoing anything my
> script got wrong. My terrible/ugly script was:
>
> var=can_match
> caps="${var^^}"
> for f in $(git grep -l "[>\.]${var}[^1-9_a-zA-Z\[]"); do
>   echo $f
>   sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)->${var} = true/set_bit(DEV_FLAG_${caps}, \&\\1->flags)/" "$f"
>   sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)\.${var} = true/dev_set_${caps}(\&\\1)/" "$f"
>   sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)->${var} = false/clear_bit(DEV_FLAG_${caps}, \&\\1->flags)/" "$f"
>   sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)\.${var} = false/dev_clear_${caps}(\&\\1)/" "$f"
>   sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)->${var} = \([^;]*\)/assign_bit(DEV_FLAG_${caps}, \&\\1->flags, \\2)/" "$f"
>   sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)\.${var} = \([^;]*\)/dev_assign_${caps}(\&\\1, \\2)/" "$f"
>   sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)->${var}\([^1-9_a-zA-Z\[]\)/test_bit(DEV_FLAG_${caps}, \&\\1->flags)\\2/" "$f"
>   sed -i~ -e "s/\([a-zA-Z_0-9\.>()-][a-zA-Z_0-9\.>()-]*\)\.${var}\([^1-9_a-zA-Z\[]\)/dev_${caps}(\&\\1)\\2/" "$f"
> done
>
> From v3 to v4, I transitioned to accessor functions with another ugly
> sed script. I had git format the old patches, then transformed them
> with:
>
> for f in *.patch; do
>   echo $f
>   sed -i~ -e "s/test_and_set_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags)/dev_test_and_set_\\L\\1(\\2)/" "$f"
>   sed -i~ -e "s/test_and_set_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags)/dev_test_and_set_\\L\\1(\\2)/" "$f"
>   sed -i~ -e "s/test_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags)/dev_\\L\\1(\\2)/" "$f"
>   sed -i~ -e "s/test_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags)/dev_\\L\\1(\\2)/" "$f"
>   sed -i~ -e "s/set_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags)/dev_set_\\L\\1(\\2)/" "$f"
>   sed -i~ -e "s/set_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags)/dev_set_\\L\\1(\\2)/" "$f"
>   sed -i~ -e "s/clear_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags)/dev_clear_\\L\\1(\\2)/" "$f"
>   sed -i~ -e "s/clear_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags)/dev_clear_\\L\\1(\\2)/" "$f"
>   sed -i~ -e "s/assign_bit(DEV_FLAG_\([^,]*\), \&\(.*\)->flags, \(.*\))/dev_assign_\\L\\1(\\2, \\3)/" "$f"
>   sed -i~ -e "s/assign_bit(DEV_FLAG_\([^,]*\), \(.*\)\.flags, \(.*\))/dev_assign_\\L\\1(\\2, \\3)/" "$f"
> done
>
> ...and then did a few manual touchups for spacing.
>
> I only marked the first patch as a "Fix" since it is the only one
> fixing observed problems. Other patches could be considered fixes too
> if folks want.
>
> I tested the first patch in the series backported to kernel 6.6 on the
> Pixel phone that was experiencing the race. I added extra printouts to
> make sure that the problem was hitting / addressed. The rest of the
> patches are tested with allmodconfig with arm32, arm64, ppc, and
> x86. I boot tested on an arm64 Chromebook running mainline.
The dma-mapping related bits are probably not race prone, but if you plan
to refactor that part I won't object.

Acked-by: Marek Szyprowski


> Changes in v5:
> - ready_to_prove => ready_to_probe typo
> - device_lock() while calling dev_set_ready_to_probe()
> - Add comment before "can_match = true" from Danilo.
> - undef __create_dev_flag_accessors
>
> Changes in v4:
> - Use accessor functions for flags
>
> Changes in v3:
> - Use a new "flags" bitfield
> - Add missing \n in probe error message
>
> Changes in v2:
> - Instead of adjusting the ordering, use "ready_to_probe" flag
>
> Douglas Anderson (9):
>   driver core: Don't let a device probe until it's ready
>   driver core: Replace dev->can_match with dev_can_match()
>   driver core: Replace dev->dma_iommu with dev_dma_iommu()
>   driver core: Replace dev->dma_skip_sync with dev_dma_skip_sync()
>   driver core: Replace dev->dma_ops_bypass with dev_dma_ops_bypass()
>   driver core: Replace dev->state_synced with dev_state_synced()
>   driver core: Replace dev->dma_coherent with dev_dma_coherent()
>   driver core: Replace dev->of_node_reused with dev_of_node_reused()
>   driver core: Replace dev->offline + ->offline_disabled with accessors
>
>  arch/arc/mm/dma.c                             |   4 +-
>  arch/arm/mach-highbank/highbank.c             |   2 +-
>  arch/arm/mach-mvebu/coherency.c               |   2 +-
>  arch/arm/mm/dma-mapping-nommu.c               |   4 +-
>  arch/arm/mm/dma-mapping.c                     |  28 ++--
>  arch/arm64/kernel/cpufeature.c                |   2 +-
>  arch/arm64/mm/dma-mapping.c                   |   2 +-
>  arch/mips/mm/dma-noncoherent.c                |   2 +-
>  arch/powerpc/kernel/dma-iommu.c               |   8 +-
>  .../platforms/pseries/hotplug-memory.c        |   4 +-
>  arch/riscv/mm/dma-noncoherent.c               |   2 +-
>  drivers/acpi/scan.c                           |   2 +-
>  drivers/base/core.c                           |  55 +++++---
>  drivers/base/cpu.c                            |   4 +-
>  drivers/base/dd.c                             |  36 ++++--
>  drivers/base/memory.c                         |   2 +-
>  drivers/base/pinctrl.c                        |   2 +-
>  drivers/base/platform.c                       |   2 +-
>  drivers/dma/ti/k3-udma-glue.c                 |   6 +-
>  drivers/dma/ti/k3-udma.c                      |   6 +-
>  drivers/iommu/dma-iommu.c                     |   9 +-
>  drivers/iommu/iommu.c                         |   5 +-
>  drivers/net/pcs/pcs-xpcs-plat.c               |   2 +-
>  drivers/of/device.c                           |   6 +-
>  drivers/pci/of.c                              |   2 +-
>  drivers/pci/pwrctrl/core.c                    |   2 +-
>  drivers/regulator/bq257xx-regulator.c         |   2 +-
>  drivers/regulator/rk808-regulator.c           |   2 +-
>  drivers/tty/serial/serial_base_bus.c          |   2 +-
>  drivers/usb/gadget/udc/aspeed-vhub/dev.c      |   2 +-
>  include/linux/device.h                        | 122 ++++++++++++------
>  include/linux/dma-map-ops.h                   |   6 +-
>  include/linux/dma-mapping.h                   |   2 +-
>  include/linux/iommu-dma.h                     |   3 +-
>  kernel/cpu.c                                  |   4 +-
>  kernel/dma/mapping.c                          |  12 +-
>  mm/hmm.c                                      |   2 +-
>  37 files changed, 218 insertions(+), 142 deletions(-)
>
Best regards

-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v5 0/9] driver core: Fix some race conditions
  2026-04-06 23:22 ` [PATCH v5 0/9] driver core: Fix some race conditions Douglas Anderson
  2026-04-06 23:23   ` [PATCH v5 8/9] driver core: Replace dev->of_node_reused with dev_of_node_reused() Douglas Anderson
  2026-04-07  8:57   ` [PATCH v5 0/9] driver core: Fix some race conditions Marek Szyprowski
@ 2026-04-07 22:58   ` Danilo Krummrich
  2 siblings, 0 replies; 6+ messages in thread
From: Danilo Krummrich @ 2026-04-07 22:58 UTC (permalink / raw)
  To: Douglas Anderson, m.szyprowski, Robin Murphy
  Cc: Greg Kroah-Hartman, Rafael J . Wysocki, Alan Stern,
	Alexey Kardashevskiy, Johan Hovold, Eric Dumazet, Leon Romanovsky,
	Christoph Hellwig, maz, Alexander Lobakin, Saravana Kannan,
	Andrew Morton, Frank.Li, Jason Gunthorpe, alex, alexander.stein,
	andre.przywara, andrew, andrew, andriy.shevchenko, aou, ardb,
	astewart, bhelgaas, brgl, broonie, catalin.marinas, chleroy,
	davem, david, devicetree, dmaengine, driver-core, gbatra,
	gregory.clement, hkallweit1, iommu, jirislaby, joel, joro, kees,
	kevin.brodsky, kuba, lenb, lgirdwood, linux-acpi,
	linux-arm-kernel, linux-aspeed, linux-cxl, linux-kernel,
	linux-mips, linux-mm, linux-pci, linux-riscv, linux-serial,
	linux-snps-arc, linux-usb, linux, linuxppc-dev, maddy, mani,
	miko.lenczewski, mpe, netdev, npiggin, osalvador, oupton, pabeni,
	palmer, peter.ujfalusi, peterz, pjw, robh, sebastian.hesselbarth,
	tglx, tsbogend, vgupta, vkoul, will, willy, yangyicong,
	yeoreum.yun

On Tue Apr 7, 2026 at 1:22 AM CEST, Douglas Anderson wrote:

Applied to driver-core-testing, thanks!

> Douglas Anderson (9):
>   driver core: Don't let a device probe until it's ready
>   driver core: Replace dev->can_match with dev_can_match()
>   driver core: Replace dev->dma_iommu with dev_dma_iommu()
>   driver core: Replace dev->dma_skip_sync with dev_dma_skip_sync()
>   driver core: Replace dev->dma_ops_bypass with dev_dma_ops_bypass()
>   driver core: Replace dev->state_synced with dev_state_synced()
>   driver core: Replace dev->dma_coherent with dev_dma_coherent()

    [ Since all DEV_FLAG_DMA_COHERENT accessors are exposed unconditionally,
      also drop the CONFIG guards around dev_assign_dma_coherent() in
      device_initialize() to ensure a correct default value. - Danilo ]

>   driver core: Replace dev->of_node_reused with dev_of_node_reused()
>   driver core: Replace dev->offline + ->offline_disabled with accessors

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2026-04-07 22:58 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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     [not found] <CGME20260406232527eucas1p2faa678aa90f0636bd17e0a7f4cb8fa28@eucas1p2.samsung.com>
2026-04-06 23:22 ` [PATCH v5 0/9] driver core: Fix some race conditions Douglas Anderson
2026-04-06 23:23   ` [PATCH v5 8/9] driver core: Replace dev->of_node_reused with dev_of_node_reused() Douglas Anderson
2026-04-07  7:27     ` Manivannan Sadhasivam
2026-04-07  9:07     ` Johan Hovold
2026-04-07  8:57   ` [PATCH v5 0/9] driver core: Fix some race conditions Marek Szyprowski
2026-04-07 22:58   ` Danilo Krummrich

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