* Re: [PATCH v3] treewide: Fix probing of devices in DT overlays
2023-03-30 13:26 [PATCH v3] treewide: Fix probing of devices in DT overlays Geert Uytterhoeven
@ 2023-03-30 19:54 ` Saravana Kannan
2023-03-31 10:18 ` Ivan Bornyakov
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Saravana Kannan @ 2023-03-30 19:54 UTC (permalink / raw)
To: geert+renesas
Cc: Greg Kroah-Hartman, Shawn Guo, Sascha Hauer,
Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
Wolfram Sang, Rob Herring, Frank Rowand, Mark Brown,
Ivan Bornyakov, linux-arm-kernel, linux-i2c, devicetree,
linux-spi, linux-renesas-soc, linux-kernel
On Thu, Mar 30, 2023 at 6:26 AM Geert Uytterhoeven
<geert+renesas@glider.be> wrote:
>
> When loading a DT overlay that creates a device, the device is not
> probed, unless the DT overlay is unloaded and reloaded again.
>
> After the recent refactoring to improve fw_devlink, it no longer depends
> on the "compatible" property to identify which device tree nodes will
> become struct devices. fw_devlink now picks up dangling consumers
> (consumers pointing to descendent device tree nodes of a device that
> aren't converted to child devices) when a device is successfully bound
> to a driver. See __fw_devlink_pickup_dangling_consumers().
>
> However, during DT overlay, a device's device tree node can have
> sub-nodes added/removed without unbinding/rebinding the driver. This
> difference in behavior between the normal device instantiation and
> probing flow vs. the DT overlay flow has a bunch of implications that
> are pointed out elsewhere[1]. One of them is that the fw_devlink logic
> to pick up dangling consumers is never exercised.
>
> This patch solves the fw_devlink issue by marking all DT nodes added by
> DT overlays with FWNODE_FLAG_NOT_DEVICE (fwnode that won't become
> device), and by clearing the flag when a struct device is actually
> created for the DT node. This way, fw_devlink knows not to have
> consumers waiting on these newly added DT nodes, and to propagate the
> dependency to an ancestor DT node that has the corresponding struct
> device.
>
> Based on a patch by Saravana Kannan, which covered only platform and spi
> devices.
Doesn't make sense to give a Reviewed-by to something I partially wrote, so:
Acked-by: Saravana Kannan <saravanak@google.com>
Thanks for making sure this is fixed Geert!
-Saravana
>
> [1] https://lore.kernel.org/r/CAGETcx_bkuFaLCiPrAWCPQz+w79ccDp6=9e881qmK=vx3hBMyg@mail.gmail.com
>
> Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()")
> Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Acked-by: Mark Brown <broonie@kernel.org>
> Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
> ---
> v3:
> - Add Acked-by,
> - s/instantiate/probe/,
> - Improve commit description,
> - Add comment before clearing FWNODE_FLAG_NOT_DEVICE,
>
> v2:
> - Add Acked-by,
> - Drop RFC.
> ---
> drivers/bus/imx-weim.c | 6 ++++++
> drivers/i2c/i2c-core-of.c | 5 +++++
> drivers/of/dynamic.c | 1 +
> drivers/of/platform.c | 5 +++++
> drivers/spi/spi.c | 5 +++++
> 5 files changed, 22 insertions(+)
>
> diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
> index 36d42484142aede2..cf463c1d2102c6fb 100644
> --- a/drivers/bus/imx-weim.c
> +++ b/drivers/bus/imx-weim.c
> @@ -329,6 +329,12 @@ static int of_weim_notify(struct notifier_block *nb, unsigned long action,
> "Failed to setup timing for '%pOF'\n", rd->dn);
>
> if (!of_node_check_flag(rd->dn, OF_POPULATED)) {
> + /*
> + * Clear the flag before adding the device so that
> + * fw_devlink doesn't skip adding consumers to this
> + * device.
> + */
> + rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
> if (!of_platform_device_create(rd->dn, NULL, &pdev->dev)) {
> dev_err(&pdev->dev,
> "Failed to create child device '%pOF'\n",
> diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
> index aa93467784c29c89..5c137638689799c8 100644
> --- a/drivers/i2c/i2c-core-of.c
> +++ b/drivers/i2c/i2c-core-of.c
> @@ -178,6 +178,11 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
> return NOTIFY_OK;
> }
>
> + /*
> + * Clear the flag before adding the device so that fw_devlink
> + * doesn't skip adding consumers to this device.
> + */
> + rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
> client = of_i2c_register_device(adap, rd->dn);
> if (IS_ERR(client)) {
> dev_err(&adap->dev, "failed to create client for '%pOF'\n",
> diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
> index 07d93753b12f5f4d..e311d406b1705306 100644
> --- a/drivers/of/dynamic.c
> +++ b/drivers/of/dynamic.c
> @@ -226,6 +226,7 @@ static void __of_attach_node(struct device_node *np)
> np->sibling = np->parent->child;
> np->parent->child = np;
> of_node_clear_flag(np, OF_DETACHED);
> + np->fwnode.flags |= FWNODE_FLAG_NOT_DEVICE;
> }
>
> /**
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index b2bd2e783445dd78..78ae8418744905c9 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -737,6 +737,11 @@ static int of_platform_notify(struct notifier_block *nb,
> if (of_node_check_flag(rd->dn, OF_POPULATED))
> return NOTIFY_OK;
>
> + /*
> + * Clear the flag before adding the device so that fw_devlink
> + * doesn't skip adding consumers to this device.
> + */
> + rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
> /* pdev_parent may be NULL when no bus platform device */
> pdev_parent = of_find_device_by_node(rd->dn->parent);
> pdev = of_platform_device_create(rd->dn, NULL,
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index 37a7be6c5a44c8f9..a12420e28640bbd4 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -4504,6 +4504,11 @@ static int of_spi_notify(struct notifier_block *nb, unsigned long action,
> return NOTIFY_OK;
> }
>
> + /*
> + * Clear the flag before adding the device so that fw_devlink
> + * doesn't skip adding consumers to this device.
> + */
> + rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
> spi = of_register_spi_device(ctlr, rd->dn);
> put_device(&ctlr->dev);
>
> --
> 2.34.1
>
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3] treewide: Fix probing of devices in DT overlays
2023-03-30 13:26 [PATCH v3] treewide: Fix probing of devices in DT overlays Geert Uytterhoeven
2023-03-30 19:54 ` Saravana Kannan
@ 2023-03-31 10:18 ` Ivan Bornyakov
2023-04-05 14:27 ` Shawn Guo
2023-04-05 20:42 ` Rob Herring
3 siblings, 0 replies; 6+ messages in thread
From: Ivan Bornyakov @ 2023-03-31 10:18 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Greg Kroah-Hartman, Saravana Kannan, Shawn Guo, Sascha Hauer,
Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
Wolfram Sang, Rob Herring, Frank Rowand, Mark Brown,
linux-arm-kernel, linux-i2c, devicetree, linux-spi,
linux-renesas-soc, linux-kernel
On Thu, Mar 30, 2023 at 03:26:13PM +0200, Geert Uytterhoeven wrote:
> When loading a DT overlay that creates a device, the device is not
> probed, unless the DT overlay is unloaded and reloaded again.
>
> After the recent refactoring to improve fw_devlink, it no longer depends
> on the "compatible" property to identify which device tree nodes will
> become struct devices. fw_devlink now picks up dangling consumers
> (consumers pointing to descendent device tree nodes of a device that
> aren't converted to child devices) when a device is successfully bound
> to a driver. See __fw_devlink_pickup_dangling_consumers().
>
> However, during DT overlay, a device's device tree node can have
> sub-nodes added/removed without unbinding/rebinding the driver. This
> difference in behavior between the normal device instantiation and
> probing flow vs. the DT overlay flow has a bunch of implications that
> are pointed out elsewhere[1]. One of them is that the fw_devlink logic
> to pick up dangling consumers is never exercised.
>
> This patch solves the fw_devlink issue by marking all DT nodes added by
> DT overlays with FWNODE_FLAG_NOT_DEVICE (fwnode that won't become
> device), and by clearing the flag when a struct device is actually
> created for the DT node. This way, fw_devlink knows not to have
> consumers waiting on these newly added DT nodes, and to propagate the
> dependency to an ancestor DT node that has the corresponding struct
> device.
>
> Based on a patch by Saravana Kannan, which covered only platform and spi
> devices.
>
> [1] https://lore.kernel.org/r/CAGETcx_bkuFaLCiPrAWCPQz+w79ccDp6=9e881qmK=vx3hBMyg@mail.gmail.com
>
> Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()")
> Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Acked-by: Mark Brown <broonie@kernel.org>
> Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Here is my use-case: a bunch of FPGA-based devices, which are SPI
slaves, WEIM childs and other platform devices, described in DTS with
status = "disabled"; in run-time DT-overlay with status = "okay" for
these devices is loaded via ConfigFS with help of out-of-tree patch.
Although without this patch I had no issues probing overlay-enabled
devices, it won't hurt either.
Tested-by: Ivan Bornyakov <i.bornyakov@metrotek.ru>
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3] treewide: Fix probing of devices in DT overlays
2023-03-30 13:26 [PATCH v3] treewide: Fix probing of devices in DT overlays Geert Uytterhoeven
2023-03-30 19:54 ` Saravana Kannan
2023-03-31 10:18 ` Ivan Bornyakov
@ 2023-04-05 14:27 ` Shawn Guo
2023-04-05 20:42 ` Rob Herring
3 siblings, 0 replies; 6+ messages in thread
From: Shawn Guo @ 2023-04-05 14:27 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Greg Kroah-Hartman, Saravana Kannan, Sascha Hauer,
Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team,
Wolfram Sang, Rob Herring, Frank Rowand, Mark Brown,
Ivan Bornyakov, linux-arm-kernel, linux-i2c, devicetree,
linux-spi, linux-renesas-soc, linux-kernel
On Thu, Mar 30, 2023 at 03:26:13PM +0200, Geert Uytterhoeven wrote:
> When loading a DT overlay that creates a device, the device is not
> probed, unless the DT overlay is unloaded and reloaded again.
>
> After the recent refactoring to improve fw_devlink, it no longer depends
> on the "compatible" property to identify which device tree nodes will
> become struct devices. fw_devlink now picks up dangling consumers
> (consumers pointing to descendent device tree nodes of a device that
> aren't converted to child devices) when a device is successfully bound
> to a driver. See __fw_devlink_pickup_dangling_consumers().
>
> However, during DT overlay, a device's device tree node can have
> sub-nodes added/removed without unbinding/rebinding the driver. This
> difference in behavior between the normal device instantiation and
> probing flow vs. the DT overlay flow has a bunch of implications that
> are pointed out elsewhere[1]. One of them is that the fw_devlink logic
> to pick up dangling consumers is never exercised.
>
> This patch solves the fw_devlink issue by marking all DT nodes added by
> DT overlays with FWNODE_FLAG_NOT_DEVICE (fwnode that won't become
> device), and by clearing the flag when a struct device is actually
> created for the DT node. This way, fw_devlink knows not to have
> consumers waiting on these newly added DT nodes, and to propagate the
> dependency to an ancestor DT node that has the corresponding struct
> device.
>
> Based on a patch by Saravana Kannan, which covered only platform and spi
> devices.
>
> [1] https://lore.kernel.org/r/CAGETcx_bkuFaLCiPrAWCPQz+w79ccDp6=9e881qmK=vx3hBMyg@mail.gmail.com
>
> Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()")
> Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Acked-by: Mark Brown <broonie@kernel.org>
> Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
> ---
> v3:
> - Add Acked-by,
> - s/instantiate/probe/,
> - Improve commit description,
> - Add comment before clearing FWNODE_FLAG_NOT_DEVICE,
>
> v2:
> - Add Acked-by,
> - Drop RFC.
> ---
> drivers/bus/imx-weim.c | 6 ++++++
Acked-by: Shawn Guo <shawnguo@kernel.org>
> drivers/i2c/i2c-core-of.c | 5 +++++
> drivers/of/dynamic.c | 1 +
> drivers/of/platform.c | 5 +++++
> drivers/spi/spi.c | 5 +++++
> 5 files changed, 22 insertions(+)
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3] treewide: Fix probing of devices in DT overlays
2023-03-30 13:26 [PATCH v3] treewide: Fix probing of devices in DT overlays Geert Uytterhoeven
` (2 preceding siblings ...)
2023-04-05 14:27 ` Shawn Guo
@ 2023-04-05 20:42 ` Rob Herring
2023-04-06 5:01 ` Greg Kroah-Hartman
3 siblings, 1 reply; 6+ messages in thread
From: Rob Herring @ 2023-04-05 20:42 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Mark Brown, devicetree, Pengutronix Kernel Team, Saravana Kannan,
Ivan Bornyakov, Greg Kroah-Hartman, Fabio Estevam, linux-i2c,
linux-renesas-soc, linux-arm-kernel, Frank Rowand, Shawn Guo,
linux-kernel, linux-spi, Rob Herring, NXP Linux Team,
Sascha Hauer, Wolfram Sang
On Thu, 30 Mar 2023 15:26:13 +0200, Geert Uytterhoeven wrote:
> When loading a DT overlay that creates a device, the device is not
> probed, unless the DT overlay is unloaded and reloaded again.
>
> After the recent refactoring to improve fw_devlink, it no longer depends
> on the "compatible" property to identify which device tree nodes will
> become struct devices. fw_devlink now picks up dangling consumers
> (consumers pointing to descendent device tree nodes of a device that
> aren't converted to child devices) when a device is successfully bound
> to a driver. See __fw_devlink_pickup_dangling_consumers().
>
> However, during DT overlay, a device's device tree node can have
> sub-nodes added/removed without unbinding/rebinding the driver. This
> difference in behavior between the normal device instantiation and
> probing flow vs. the DT overlay flow has a bunch of implications that
> are pointed out elsewhere[1]. One of them is that the fw_devlink logic
> to pick up dangling consumers is never exercised.
>
> This patch solves the fw_devlink issue by marking all DT nodes added by
> DT overlays with FWNODE_FLAG_NOT_DEVICE (fwnode that won't become
> device), and by clearing the flag when a struct device is actually
> created for the DT node. This way, fw_devlink knows not to have
> consumers waiting on these newly added DT nodes, and to propagate the
> dependency to an ancestor DT node that has the corresponding struct
> device.
>
> Based on a patch by Saravana Kannan, which covered only platform and spi
> devices.
>
> [1] https://lore.kernel.org/r/CAGETcx_bkuFaLCiPrAWCPQz+w79ccDp6=9e881qmK=vx3hBMyg@mail.gmail.com
>
> Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()")
> Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Acked-by: Mark Brown <broonie@kernel.org>
> Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
> ---
> v3:
> - Add Acked-by,
> - s/instantiate/probe/,
> - Improve commit description,
> - Add comment before clearing FWNODE_FLAG_NOT_DEVICE,
>
> v2:
> - Add Acked-by,
> - Drop RFC.
> ---
> drivers/bus/imx-weim.c | 6 ++++++
> drivers/i2c/i2c-core-of.c | 5 +++++
> drivers/of/dynamic.c | 1 +
> drivers/of/platform.c | 5 +++++
> drivers/spi/spi.c | 5 +++++
> 5 files changed, 22 insertions(+)
>
Applied, thanks!
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v3] treewide: Fix probing of devices in DT overlays
2023-04-05 20:42 ` Rob Herring
@ 2023-04-06 5:01 ` Greg Kroah-Hartman
0 siblings, 0 replies; 6+ messages in thread
From: Greg Kroah-Hartman @ 2023-04-06 5:01 UTC (permalink / raw)
To: Rob Herring
Cc: Geert Uytterhoeven, Mark Brown, devicetree,
Pengutronix Kernel Team, Saravana Kannan, Ivan Bornyakov,
Fabio Estevam, linux-i2c, linux-renesas-soc, linux-arm-kernel,
Frank Rowand, Shawn Guo, linux-kernel, linux-spi, Rob Herring,
NXP Linux Team, Sascha Hauer, Wolfram Sang
On Wed, Apr 05, 2023 at 03:42:52PM -0500, Rob Herring wrote:
>
> On Thu, 30 Mar 2023 15:26:13 +0200, Geert Uytterhoeven wrote:
> > When loading a DT overlay that creates a device, the device is not
> > probed, unless the DT overlay is unloaded and reloaded again.
> >
> > After the recent refactoring to improve fw_devlink, it no longer depends
> > on the "compatible" property to identify which device tree nodes will
> > become struct devices. fw_devlink now picks up dangling consumers
> > (consumers pointing to descendent device tree nodes of a device that
> > aren't converted to child devices) when a device is successfully bound
> > to a driver. See __fw_devlink_pickup_dangling_consumers().
> >
> > However, during DT overlay, a device's device tree node can have
> > sub-nodes added/removed without unbinding/rebinding the driver. This
> > difference in behavior between the normal device instantiation and
> > probing flow vs. the DT overlay flow has a bunch of implications that
> > are pointed out elsewhere[1]. One of them is that the fw_devlink logic
> > to pick up dangling consumers is never exercised.
> >
> > This patch solves the fw_devlink issue by marking all DT nodes added by
> > DT overlays with FWNODE_FLAG_NOT_DEVICE (fwnode that won't become
> > device), and by clearing the flag when a struct device is actually
> > created for the DT node. This way, fw_devlink knows not to have
> > consumers waiting on these newly added DT nodes, and to propagate the
> > dependency to an ancestor DT node that has the corresponding struct
> > device.
> >
> > Based on a patch by Saravana Kannan, which covered only platform and spi
> > devices.
> >
> > [1] https://lore.kernel.org/r/CAGETcx_bkuFaLCiPrAWCPQz+w79ccDp6=9e881qmK=vx3hBMyg@mail.gmail.com
> >
> > Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()")
> > Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > Acked-by: Mark Brown <broonie@kernel.org>
> > Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
> > ---
> > v3:
> > - Add Acked-by,
> > - s/instantiate/probe/,
> > - Improve commit description,
> > - Add comment before clearing FWNODE_FLAG_NOT_DEVICE,
> >
> > v2:
> > - Add Acked-by,
> > - Drop RFC.
> > ---
> > drivers/bus/imx-weim.c | 6 ++++++
> > drivers/i2c/i2c-core-of.c | 5 +++++
> > drivers/of/dynamic.c | 1 +
> > drivers/of/platform.c | 5 +++++
> > drivers/spi/spi.c | 5 +++++
> > 5 files changed, 22 insertions(+)
> >
>
> Applied, thanks!
Oops, I thought I had to take this. I'll go drop it from my tree...
thanks,
greg k-h
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^ permalink raw reply [flat|nested] 6+ messages in thread