From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailout4.samsung.com ([203.254.224.34]) by bombadil.infradead.org with esmtp (Exim 4.72 #1 (Red Hat Linux)) id 1P0837-00033G-K8 for linux-mtd@lists.infradead.org; Mon, 27 Sep 2010 07:22:58 +0000 Received: from epmmp1 (mailout4.samsung.com [203.254.224.34]) by mailout4.samsung.com (Sun Java(tm) System Messaging Server 7u3-15.01 64bit (built Feb 12 2010)) with ESMTP id <0L9E00IXM9U8TPB0@mailout4.samsung.com> for linux-mtd@lists.infradead.org; Mon, 27 Sep 2010 16:22:56 +0900 (KST) Received: from TNRNDGASPAPP1.tn.corp.samsungelectronics.net ([165.213.149.150]) by mmp1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0L9E00HJS9U8O2@mmp1.samsung.com> for linux-mtd@lists.infradead.org; Mon, 27 Sep 2010 16:22:56 +0900 (KST) Date: Mon, 27 Sep 2010 16:25:17 +0900 From: Kyungmin Park Subject: [PATCH 4/4] MTD: OneNAND: S5PC110: Add timeout to prevent the endless loop To: linux-mtd@lists.infradead.org Message-id: <20100927072517.GA32095@july> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT Content-disposition: inline Cc: Artem.Bityutskiy@nokia.com, dwmw2@infradead.org List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Kyungmin Park There's no case timeout but add it for some H/W problem or wrong codes implementation Signed-off-by: Kyungmin Park --- drivers/mtd/onenand/samsung.c | 11 ++++++++++- 1 files changed, 10 insertions(+), 1 deletions(-) diff --git a/drivers/mtd/onenand/samsung.c b/drivers/mtd/onenand/samsung.c index 30eccd7..afdb4c5 100644 --- a/drivers/mtd/onenand/samsung.c +++ b/drivers/mtd/onenand/samsung.c @@ -535,6 +535,7 @@ static int s5pc110_dma_ops(void *dst, void *src, size_t count, int direction) { void __iomem *base = onenand->dma_addr; int status; + unsigned long timeout; writel(src, base + S5PC110_DMA_SRC_ADDR); writel(dst, base + S5PC110_DMA_DST_ADDR); @@ -552,6 +553,13 @@ static int s5pc110_dma_ops(void *dst, void *src, size_t count, int direction) writel(S5PC110_DMA_TRANS_CMD_TR, base + S5PC110_DMA_TRANS_CMD); + /* + * There's no exact timeout values at Spec. + * In real case it takes under 1 msec. + * So 20 msecs are enough. + */ + timeout = jiffies + msecs_to_jiffies(20); + do { status = readl(base + S5PC110_DMA_TRANS_STATUS); if (status & S5PC110_DMA_TRANS_STATUS_TE) { @@ -559,7 +567,8 @@ static int s5pc110_dma_ops(void *dst, void *src, size_t count, int direction) base + S5PC110_DMA_TRANS_CMD); return -EIO; } - } while (!(status & S5PC110_DMA_TRANS_STATUS_TD)); + } while (!(status & S5PC110_DMA_TRANS_STATUS_TD) && + time_before(jiffies, timeout)); writel(S5PC110_DMA_TRANS_CMD_TDC, base + S5PC110_DMA_TRANS_CMD); -- 1.5.3.3