From b1c37bec1ccfe5ccab72bc0ddc0dfa45c43e2de2 Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Tue, 4 Apr 2023 18:21:23 +0100 Subject: [PATCH] nvmem: core: request layout modules loading When a storage device like an eeprom or an mtd device probes, it registers an nvmem device if the nvmem subsystem has been enabled (bool symbol). During nvmem registration, if the device is using layouts to expose dynamic nvmem cells, the core will first try to get a reference over the layout driver callbacks. In practice there is not relationship that can be described between the storage driver and the nvmem layout. So there is no way we can enforce both drivers will be built-in or both will be modules. If the storage device driver is built-in but the layout is built as a module, instead of badly failing with an endless probe deferral loop, lets just make a modprobe call in case the driver was made available in an initramfs with of_device_node_request_module(), and offer a fully functional system to the user. Signed-off-by: Miquel Raynal Tested-by: Michael Walle Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-16-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -17,6 +17,7 @@ #include #include #include +#include #include struct nvmem_device { @@ -761,6 +762,13 @@ static struct nvmem_layout *nvmem_layout if (!layout_np) return NULL; + /* + * In case the nvmem device was built-in while the layout was built as a + * module, we shall manually request the layout driver loading otherwise + * we'll never have any match. + */ + of_request_module(layout_np); + spin_lock(&nvmem_layout_lock); list_for_each_entry(l, &nvmem_layouts, node) {