From 6468a6f45148fb5e95c86b4efebf63f9abcd2137 Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Tue, 4 Apr 2023 18:21:22 +0100 Subject: [PATCH] nvmem: core: handle the absence of expected layouts Make nvmem_layout_get() return -EPROBE_DEFER while the expected layout is not available. This condition cannot be triggered today as nvmem layout drivers are initialed as part of an early init call, but soon these drivers will be converted into modules and be initialized with a standard priority, so the unavailability of the drivers might become a reality that must be taken care of. Let's anticipate this by telling the caller the layout might not yet be available. A probe deferral is requested in this case. Please note this does not affect any nvmem device not using layouts, because an early check against the "nvmem-layout" container presence will return NULL in this case. Signed-off-by: Miquel Raynal Tested-by: Michael Walle Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-15-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -755,7 +755,7 @@ EXPORT_SYMBOL_GPL(nvmem_layout_unregiste static struct nvmem_layout *nvmem_layout_get(struct nvmem_device *nvmem) { struct device_node *layout_np, *np = nvmem->dev.of_node; - struct nvmem_layout *l, *layout = NULL; + struct nvmem_layout *l, *layout = ERR_PTR(-EPROBE_DEFER); layout_np = of_get_child_by_name(np, "nvmem-layout"); if (!layout_np) @@ -938,6 +938,13 @@ struct nvmem_device *nvmem_register(cons * pointer will be NULL and nvmem_layout_put() will be a noop. */ nvmem->layout = config->layout ?: nvmem_layout_get(nvmem); + if (IS_ERR(nvmem->layout)) { + rval = PTR_ERR(nvmem->layout); + nvmem->layout = NULL; + + if (rval == -EPROBE_DEFER) + goto err_teardown_compat; + } if (config->cells) { rval = nvmem_add_cells(nvmem, config->cells, config->ncells); @@ -970,6 +977,7 @@ struct nvmem_device *nvmem_register(cons err_remove_cells: nvmem_device_remove_all_cells(nvmem); nvmem_layout_put(nvmem->layout); +err_teardown_compat: if (config->compat) nvmem_sysfs_remove_compat(nvmem, config); err_put_device: