nvmem: properly handle returned value nvmem_reg_read

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@debian.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 3636104..b5b0cdc 100644 (file)
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -1119,6 +1119,8 @@ static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell,
 
                /* 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 */
@@ -1137,11 +1139,16 @@ static void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell,
                /* 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);
 }
 
 /**