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authorGeert Uytterhoeven <geert+renesas@glider.be>2023-03-30 15:26:13 +0200
committerRob Herring <robh@kernel.org>2023-04-11 21:39:52 +0200
commit1a50d9403fb90cbe4dea0ec9fd0351d2ecbd8924 (patch)
tree28951664bc283d248bd30a565ddcba34f792034c /drivers/bus
parentdt-bindings: interrupt-controller: loongarch: Fix mismatched compatible (diff)
downloadlinux-1a50d9403fb90cbe4dea0ec9fd0351d2ecbd8924.tar.xz
linux-1a50d9403fb90cbe4dea0ec9fd0351d2ecbd8924.zip
treewide: Fix probing of devices in DT overlays
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 Acked-by: Shawn Guo <shawnguo@kernel.org> Acked-by: Saravana Kannan <saravanak@google.com> Tested-by: Ivan Bornyakov <i.bornyakov@metrotek.ru> Link: https://lore.kernel.org/r/e1fa546682ea4c8474ff997ab6244c5e11b6f8bc.1680182615.git.geert+renesas@glider.be Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers/bus')
-rw-r--r--drivers/bus/imx-weim.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index 828c66bbaa67..a8dfe94491fd 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -331,6 +331,12 @@ 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",