include/linux/dmaengine.h:1370:10: warning: 'caps.descriptor_reuse' is used uninitialized in this function

From: kbuild test robot
Date: Thu Dec 05 2019 - 03:25:49 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 2f13437b8917627119d163d62f73e7a78a92303a
commit: 8259bf667a0f9ea1a37bb71c7af9ebd550e9251d spi: bcm2835: Speed up TX-only DMA transfers by clearing RX FIFO
date: 3 months ago
config: x86_64-randconfig-s0-20191205 (attached as .config)
compiler: gcc-4.9 (Debian 4.9.2-10+deb8u1) 4.9.2
reproduce:
git checkout 8259bf667a0f9ea1a37bb71c7af9ebd550e9251d
# save the attached .config to linux build tree
make ARCH=x86_64

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

In file included from drivers/spi/spi-bcm2835.c:19:0:
drivers/spi/spi-bcm2835.c: In function 'dmaengine_desc_set_reuse':
>> include/linux/dmaengine.h:1370:10: warning: 'caps.descriptor_reuse' is used uninitialized in this function [-Wuninitialized]
if (caps.descriptor_reuse) {
^
--
In file included from drivers//spi/spi-bcm2835.c:19:0:
drivers//spi/spi-bcm2835.c: In function 'dmaengine_desc_set_reuse':
>> include/linux/dmaengine.h:1370:10: warning: 'caps.descriptor_reuse' is used uninitialized in this function [-Wuninitialized]
if (caps.descriptor_reuse) {
^

vim +1370 include/linux/dmaengine.h

a8135d0d79e9d0 Peter Ujfalusi 2015-12-14 1363
272420214d261e Vinod Koul 2015-08-05 1364 static inline int dmaengine_desc_set_reuse(struct dma_async_tx_descriptor *tx)
272420214d261e Vinod Koul 2015-08-05 1365 {
272420214d261e Vinod Koul 2015-08-05 1366 struct dma_slave_caps caps;
272420214d261e Vinod Koul 2015-08-05 1367
272420214d261e Vinod Koul 2015-08-05 1368 dma_get_slave_caps(tx->chan, &caps);
272420214d261e Vinod Koul 2015-08-05 1369
272420214d261e Vinod Koul 2015-08-05 @1370 if (caps.descriptor_reuse) {
272420214d261e Vinod Koul 2015-08-05 1371 tx->flags |= DMA_CTRL_REUSE;
272420214d261e Vinod Koul 2015-08-05 1372 return 0;
272420214d261e Vinod Koul 2015-08-05 1373 } else {
272420214d261e Vinod Koul 2015-08-05 1374 return -EPERM;
272420214d261e Vinod Koul 2015-08-05 1375 }
272420214d261e Vinod Koul 2015-08-05 1376 }
272420214d261e Vinod Koul 2015-08-05 1377

:::::: The code at line 1370 was first introduced by commit
:::::: 272420214d261e97f08a4c555defb3924de06ae8 dmaengine: Add DMA_CTRL_REUSE

:::::: TO: Vinod Koul <vinod.koul@xxxxxxxxx>
:::::: CC: Vinod Koul <vinod.koul@xxxxxxxxx>

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