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From:   Miaoqian Lin <linmq006@gmail.com>
To:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Pratyush Yadav <p.yadav@ti.com>,
        Miaoqian Lin <linmq006@gmail.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Paul Cercueil <paul@crapouillou.net>,
        Guennadi Liakhovetski <g.liakhovetski@gmx.de>,
        Artem Bityutskiy <artem.bityutskiy@linux.intel.com>,
        Bastian Hecht <hechtb@googlemail.com>,
        linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] mtd: rawnand: Fix return value check of wait_for_completion_timeout
Date:   Tue, 12 Apr 2022 02:08:30 +0000
Message-Id: <20220412020834.7161-1-linmq006@gmail.com>
Precedence: bulk

wait_for_completion_timeout() returns unsigned long not int.
It returns 0 if timed out, and positive if completed.
The check for <= 0 is ambiguous and should be == 0 here
indicating timeout which is the only error case.

Fixes: 83738d87e3a0 ("mtd: sh_flctl: Add DMA capabilty")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
 drivers/mtd/nand/raw/sh_flctl.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/raw/sh_flctl.c b/drivers/mtd/nand/raw/sh_flctl.c
index b85b9c6fcc42..4f326a2dd170 100644
--- a/drivers/mtd/nand/raw/sh_flctl.c
+++ b/drivers/mtd/nand/raw/sh_flctl.c
@@ -385,6 +385,7 @@ static int flctl_dma_fifo0_transfer(struct sh_flctl *flctl, unsigned long *buf,
 	dma_cookie_t cookie;
 	uint32_t reg;
 	int ret;
+	unsigned long time_left;
 
 	if (dir == DMA_FROM_DEVICE) {
 		chan = flctl->chan_fifo0_rx;
@@ -425,13 +426,14 @@ static int flctl_dma_fifo0_transfer(struct sh_flctl *flctl, unsigned long *buf,
 		goto out;
 	}
 
-	ret =
+	time_left =
 	wait_for_completion_timeout(&flctl->dma_complete,
 				msecs_to_jiffies(3000));
 
-	if (ret <= 0) {
+	if (time_left == 0) {
 		dmaengine_terminate_all(chan);
 		dev_err(&flctl->pdev->dev, "wait_for_completion_timeout\n");
+		ret = -ETIMEDOUT;
 	}
 
 out:
-- 
2.17.1