From 824a6c4cdf73abdd188b5a1e55fba7c63e18ea81 Mon Sep 17 00:00:00 2001 From: Srinivas Kandagatla Date: Tue, 6 Nov 2018 15:41:41 +0000 Subject: [PATCH] BACKPORT: nvmem: core: fix regression in of_nvmem_cell_get() NVMEM DT support seems to be totally broken after commit e888d445ac33 ("nvmem: resolve cells from DT at registration time") Fix this! Index used in of_nvmem_cell_get() to find cell is specific to consumer, It can not be used for searching the cell in provider. Use device_node instead of this to find the matching cell in device tree case. Fixes: e888d445ac33 ("nvmem: resolve cells from DT at registration time") Reported-by: Niklas Cassel Signed-off-by: Srinivas Kandagatla Tested-by: Niklas Cassel Signed-off-by: Greg Kroah-Hartman Git-commit: 0749aa25af82c690395a96e799cd2c6e54c459cf Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git [gkohli@codeaurora: Resolve trivial merge conflicts] Signed-off-by: Gaurav Kohli (cherry picked from commit 0749aa25af82c690395a96e799cd2c6e54c459cf) Signed-off-by: Mark Salyzyn Bug: 150014847 Change-Id: I856c6f71c7da7ab50966dabd700ae1513ea16fa6 --- drivers/nvmem/core.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index aeab47404a8a..148f60eccfb7 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -51,6 +51,7 @@ struct nvmem_cell { int bytes; int bit_offset; int nbits; + struct device_node *np; struct nvmem_device *nvmem; struct list_head node; }; @@ -304,6 +305,7 @@ static void nvmem_cell_drop(struct nvmem_cell *cell) mutex_lock(&nvmem_cells_mutex); list_del(&cell->node); mutex_unlock(&nvmem_cells_mutex); + of_node_put(cell->np); kfree(cell); } @@ -468,6 +470,7 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem) return -ENOMEM; cell->nvmem = nvmem; + cell->np = of_node_get(child); cell->offset = be32_to_cpup(addr++); cell->bytes = be32_to_cpup(addr); cell->name = child->name; @@ -892,14 +895,13 @@ static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id) #if IS_ENABLED(CONFIG_OF) static struct nvmem_cell * -nvmem_find_cell_by_index(struct nvmem_device *nvmem, int index) +nvmem_find_cell_by_node(struct nvmem_device *nvmem, struct device_node *np) { struct nvmem_cell *cell = NULL; - int i = 0; mutex_lock(&nvmem_mutex); list_for_each_entry(cell, &nvmem_cells, node) { - if (index == i++) + if (np == cell->np) break; } mutex_unlock(&nvmem_mutex); @@ -944,7 +946,7 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, if (IS_ERR(nvmem)) return ERR_CAST(nvmem); - cell = nvmem_find_cell_by_index(nvmem, index); + cell = nvmem_find_cell_by_node(nvmem, cell_np); if (!cell) { __nvmem_device_put(nvmem); return ERR_PTR(-ENOENT);