From a45e47f4b342884dcf9e40a530033f64c379ffc7 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Mon, 27 Feb 2017 21:42:16 +0100 Subject: staging: fsl-mc: fix warning in DT ranges parser The fsl-mc-bus driver in staging contains a copy of the standard 'ranges' property parsing algorithm with a hack to treat a missing property the same way as an empty one. This code produces false-positive warnings for me in an allmodconfig build: drivers/staging/fsl-mc/bus/fsl-mc-bus.c: In function 'fsl_mc_bus_probe': drivers/staging/fsl-mc/bus/fsl-mc-bus.c:645:6: error: 'mc_size_cells' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/staging/fsl-mc/bus/fsl-mc-bus.c:682:8: error: 'mc_addr_cells' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/staging/fsl-mc/bus/fsl-mc-bus.c:644:6: note: 'mc_addr_cells' was declared here drivers/staging/fsl-mc/bus/fsl-mc-bus.c:684:8: error: 'paddr_cells' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/staging/fsl-mc/bus/fsl-mc-bus.c:643:6: note: 'paddr_cells' was declared here To avoid the warnings, I'm simplifying the argument handling to pass the number of valid ranges in the property as the function return code rather than passing it by reference. With this change, gcc can see that we don't evaluate the cell numbers for an missing ranges property. Signed-off-by: Arnd Bergmann Acked-by: Laurentiu Tudor Signed-off-by: Greg Kroah-Hartman --- drivers/staging/fsl-mc/bus/fsl-mc-bus.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) (limited to 'drivers/staging') diff --git a/drivers/staging/fsl-mc/bus/fsl-mc-bus.c b/drivers/staging/fsl-mc/bus/fsl-mc-bus.c index 47acb0a29842..3be5f25ff113 100644 --- a/drivers/staging/fsl-mc/bus/fsl-mc-bus.c +++ b/drivers/staging/fsl-mc/bus/fsl-mc-bus.c @@ -588,8 +588,7 @@ static int parse_mc_ranges(struct device *dev, int *paddr_cells, int *mc_addr_cells, int *mc_size_cells, - const __be32 **ranges_start, - u8 *num_ranges) + const __be32 **ranges_start) { const __be32 *prop; int range_tuple_cell_count; @@ -602,8 +601,6 @@ static int parse_mc_ranges(struct device *dev, dev_warn(dev, "missing or empty ranges property for device tree node '%s'\n", mc_node->name); - - *num_ranges = 0; return 0; } @@ -630,8 +627,7 @@ static int parse_mc_ranges(struct device *dev, return -EINVAL; } - *num_ranges = ranges_len / tuple_len; - return 0; + return ranges_len / tuple_len; } static int get_mc_addr_translation_ranges(struct device *dev, @@ -639,7 +635,7 @@ static int get_mc_addr_translation_ranges(struct device *dev, **ranges, u8 *num_ranges) { - int error; + int ret; int paddr_cells; int mc_addr_cells; int mc_size_cells; @@ -647,16 +643,16 @@ static int get_mc_addr_translation_ranges(struct device *dev, const __be32 *ranges_start; const __be32 *cell; - error = parse_mc_ranges(dev, + ret = parse_mc_ranges(dev, &paddr_cells, &mc_addr_cells, &mc_size_cells, - &ranges_start, - num_ranges); - if (error < 0) - return error; + &ranges_start); + if (ret < 0) + return ret; - if (!(*num_ranges)) { + *num_ranges = ret; + if (!ret) { /* * Missing or empty ranges property ("ranges;") for the * 'fsl,qoriq-mc' node. In this case, identity mapping -- cgit v1.2.3