4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mathieu Malaterre <malat@xxxxxxxxxx> [ Upstream commit 50808bfcc14b854775a9f1d0abe3dac2babcf5c3 ] Function nvmem_reg_read can return a non zero value indicating an error. This returned value must be read and error propagated to nvmem_cell_prepare_write_buffer. Silence the following gcc warning (W=1): drivers/nvmem/core.c:1093:9: warning: variable 'rc' set but not used [-Wunused-but-set-variable] Signed-off-by: Mathieu Malaterre <malat@xxxxxxxxxx> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/nvmem/core.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -1031,6 +1031,8 @@ static inline void *nvmem_cell_prepare_w /* setup the first byte with lsb bits from nvmem */ rc = nvmem_reg_read(nvmem, cell->offset, &v, 1); + if (rc) + goto err; *b++ |= GENMASK(bit_offset - 1, 0) & v; /* setup rest of the byte if any */ @@ -1049,11 +1051,16 @@ static inline void *nvmem_cell_prepare_w /* setup the last byte with msb bits from nvmem */ rc = nvmem_reg_read(nvmem, cell->offset + cell->bytes - 1, &v, 1); + if (rc) + goto err; *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v; } return buf; +err: + kfree(buf); + return ERR_PTR(rc); } /**