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From d8d9b9055d704d6f84ef6346d6826b8a9640f209 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Mon, 22 Oct 2012 10:25:39 +0200
Subject: [PATCH 112/123] MTD: lantiq: xway: fix NAND reset timeout handling
Fixes a possible deadlock in the code that resets the NAND flash.
http://lists.infradead.org/pipermail/linux-mtd/2012-September/044240.html
Signed-off-by: John Crispin <blogic@openwrt.org>
---
drivers/mtd/nand/xway_nand.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
--- a/drivers/mtd/nand/xway_nand.c
+++ b/drivers/mtd/nand/xway_nand.c
@@ -58,15 +58,23 @@ static void xway_reset_chip(struct nand_
{
unsigned long nandaddr = (unsigned long) chip->IO_ADDR_W;
unsigned long flags;
+ unsigned long timeout;
nandaddr &= ~NAND_WRITE_ADDR;
nandaddr |= NAND_WRITE_CMD;
/* finish with a reset */
+ timeout = jiffies + msecs_to_jiffies(200);
+
spin_lock_irqsave(&ebu_lock, flags);
+
writeb(NAND_WRITE_CMD_RESET, (void __iomem *) nandaddr);
- while ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
- ;
+ do {
+ if ((ltq_ebu_r32(EBU_NAND_WAIT) & NAND_WAIT_WR_C) == 0)
+ break;
+ cond_resched();
+ } while (!time_after_eq(jiffies, timeout));
+
spin_unlock_irqrestore(&ebu_lock, flags);
}
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