[PATCH] spi: qup: hide warning for uninitialized variable

From: Arnd Bergmann
Date: Thu Aug 10 2017 - 08:13:26 EST


The added conditionals in this function apparently confused
gcc to the point that it no longer sees the code is safe and
instead shows a false-positive warning:

drivers/spi/spi-qup.c: In function 'spi_qup_transfer_one':
drivers/spi/spi-qup.c:507:28: error: 'tx_nents' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/spi/spi-qup.c:464:17: note: 'tx_nents' was declared here
drivers/spi/spi-qup.c:505:28: error: 'rx_nents' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/spi/spi-qup.c:464:7: note: 'rx_nents' was declared here

This moves the initialization to a place that makes it obvious
to the compiler.

Fixes: 5884e17ef3cb ("spi: qup: allow multiple DMA transactions per spi xfer")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
drivers/spi/spi-qup.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
index 1364516e87c2..e9ecd67cd817 100644
--- a/drivers/spi/spi-qup.c
+++ b/drivers/spi/spi-qup.c
@@ -427,8 +427,6 @@ static u32 spi_qup_sgl_get_nents_len(struct scatterlist *sgl, u32 max,
struct scatterlist *sg;
u32 total = 0;

- *nents = 0;
-
for (sg = sgl; sg; sg = sg_next(sg)) {
unsigned int len = sg_dma_len(sg);

@@ -461,7 +459,7 @@ static int spi_qup_do_dma(struct spi_device *spi, struct spi_transfer *xfer,
tx_sgl = xfer->tx_sg.sgl;

do {
- u32 rx_nents, tx_nents;
+ u32 rx_nents = 0, tx_nents = 0;

if (rx_sgl)
qup->n_words = spi_qup_sgl_get_nents_len(rx_sgl,
--
2.13.2