From f419a08fb329e235df0cb8e329cff770e02d171a Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 25 Mar 2016 14:21:47 -0700 Subject: [PATCH] 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 Cc: Maxim Levitsky Cc: Quentin Lambert Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/memstick/host/r592.c | 3 +-- 1 file changed, 1 insertion(+), 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; } -- 2.20.1