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| author | Arnd Bergmann <arnd@arndb.de> | 2016-03-25 14:21:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-25 16:37:42 -0700 |
| commit | f419a08fb329e235df0cb8e329cff770e02d171a (patch) | |
| tree | 63947643cc8dae7f61f375478af28cb8dc960b3a /drivers/memstick | |
| parent | 102c2595aa193f598c0f4b1bf2037d168c80e551 (diff) | |
| download | lwn-f419a08fb329e235df0cb8e329cff770e02d171a.tar.gz lwn-f419a08fb329e235df0cb8e329cff770e02d171a.zip | |
drivers/memstick/host/r592.c: avoid gcc-6 warning
The r592 driver relies on behavior of the DMA mapping API that is
normally observed but not guaranteed by the API. Instead it uses a
runtime check to fail transfers if the API ever behaves
When CONFIG_NEED_SG_DMA_LENGTH is not set, one of the checks turns into a
comparison of a variable with itself, which gcc-6.0 now warns about:
drivers/memstick/host/r592.c: In function 'r592_transfer_fifo_dma':
drivers/memstick/host/r592.c:302:31: error: self-comparison always evaluates to false [-Werror=tautological-compare]
(sg_dma_len(&dev->req->sg) < dev->req->sg.length)) {
^
The check itself is not a problem, so this patch just rephrases the
condition in a way that gcc does not consider an indication of a mistake.
We already know that dev->req->sg.length was initially R592_LFIFO_SIZE, so
we can compare it to that constant again.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Quentin Lambert <lambert.quentin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/memstick')
| -rw-r--r-- | drivers/memstick/host/r592.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/memstick/host/r592.c b/drivers/memstick/host/r592.c index ef09ba0289d7..d5cfb503b9d6 100644 --- a/drivers/memstick/host/r592.c +++ b/drivers/memstick/host/r592.c @@ -298,8 +298,7 @@ static int r592_transfer_fifo_dma(struct r592_device *dev) sg_count = dma_map_sg(&dev->pci_dev->dev, &dev->req->sg, 1, is_write ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE); - if (sg_count != 1 || - (sg_dma_len(&dev->req->sg) < dev->req->sg.length)) { + if (sg_count != 1 || sg_dma_len(&dev->req->sg) < R592_LFIFO_SIZE) { message("problem in dma_map_sg"); return -EIO; } |