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From: Christian Pellegrin <chripell@fsfe.org>
To: ben-linux@fluff.org, linux-samsung-soc@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: Christian Pellegrin <chripell@fsfe.org>
Subject: [PATCH v2.6.34-rc2] s3c: Fix CONFIG_MTD_NAND_S3C2410_CLKSTOP
Date: Tue, 30 Mar 2010 10:22:03 +0200	[thread overview]
Message-ID: <1269937323-7541-1-git-send-email-chripell@fsfe.org> (raw)

Option CONFIG_MTD_NAND_S3C2410_CLKSTOP was broken by higher MTD layers
calling select_chip with -1 twice in a row. This patch fixes the problem
by making sure that clk_disable is not called too many times.

Signed-off-by: Christian Pellegrin <chripell@fsfe.org>
---
 drivers/mtd/nand/s3c2410.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index fa6e9c7..9adecc6 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -37,6 +37,7 @@
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/cpufreq.h>
+#include <linux/bitops.h>
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
@@ -135,6 +136,9 @@ struct s3c2410_nand_info {
 #ifdef CONFIG_CPU_FREQ
 	struct notifier_block	freq_transition;
 #endif
+#ifdef CONFIG_MTD_NAND_S3C2410_CLKSTOP
+	unsigned long                   clk_running;
+#endif
 };
 
 /* conversion functions */
@@ -333,7 +337,8 @@ static void s3c2410_nand_select_chip(struct mtd_info *mtd, int chip)
 	nmtd = this->priv;
 	info = nmtd->info;
 
-	if (chip != -1 && allow_clk_stop(info))
+	if (chip != -1 && allow_clk_stop(info) &&
+	    !test_and_set_bit(0, &info->clk_running))
 		clk_enable(info->clk);
 
 	cur = readl(info->sel_reg);
@@ -356,7 +361,8 @@ static void s3c2410_nand_select_chip(struct mtd_info *mtd, int chip)
 
 	writel(cur, info->sel_reg);
 
-	if (chip == -1 && allow_clk_stop(info))
+	if (chip == -1 && allow_clk_stop(info) &&
+	    test_and_clear_bit(0, &info->clk_running))
 		clk_disable(info->clk);
 }
 
-- 
1.5.6.5

WARNING: multiple messages have this Message-ID (diff)
From: chripell@fsfe.org (Christian Pellegrin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2.6.34-rc2] s3c: Fix CONFIG_MTD_NAND_S3C2410_CLKSTOP
Date: Tue, 30 Mar 2010 10:22:03 +0200	[thread overview]
Message-ID: <1269937323-7541-1-git-send-email-chripell@fsfe.org> (raw)

Option CONFIG_MTD_NAND_S3C2410_CLKSTOP was broken by higher MTD layers
calling select_chip with -1 twice in a row. This patch fixes the problem
by making sure that clk_disable is not called too many times.

Signed-off-by: Christian Pellegrin <chripell@fsfe.org>
---
 drivers/mtd/nand/s3c2410.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
index fa6e9c7..9adecc6 100644
--- a/drivers/mtd/nand/s3c2410.c
+++ b/drivers/mtd/nand/s3c2410.c
@@ -37,6 +37,7 @@
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/cpufreq.h>
+#include <linux/bitops.h>
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/nand.h>
@@ -135,6 +136,9 @@ struct s3c2410_nand_info {
 #ifdef CONFIG_CPU_FREQ
 	struct notifier_block	freq_transition;
 #endif
+#ifdef CONFIG_MTD_NAND_S3C2410_CLKSTOP
+	unsigned long                   clk_running;
+#endif
 };
 
 /* conversion functions */
@@ -333,7 +337,8 @@ static void s3c2410_nand_select_chip(struct mtd_info *mtd, int chip)
 	nmtd = this->priv;
 	info = nmtd->info;
 
-	if (chip != -1 && allow_clk_stop(info))
+	if (chip != -1 && allow_clk_stop(info) &&
+	    !test_and_set_bit(0, &info->clk_running))
 		clk_enable(info->clk);
 
 	cur = readl(info->sel_reg);
@@ -356,7 +361,8 @@ static void s3c2410_nand_select_chip(struct mtd_info *mtd, int chip)
 
 	writel(cur, info->sel_reg);
 
-	if (chip == -1 && allow_clk_stop(info))
+	if (chip == -1 && allow_clk_stop(info) &&
+	    test_and_clear_bit(0, &info->clk_running))
 		clk_disable(info->clk);
 }
 
-- 
1.5.6.5

             reply	other threads:[~2010-03-30  8:24 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-30  8:22 Christian Pellegrin [this message]
2010-03-30  8:22 ` [PATCH v2.6.34-rc2] s3c: Fix CONFIG_MTD_NAND_S3C2410_CLKSTOP Christian Pellegrin
2010-05-04  6:57 ` Ben Dooks
2010-05-04  6:57   ` Ben Dooks
2010-05-04  7:13   ` christian pellegrin
2010-05-04  7:13     ` christian pellegrin
2010-05-06  5:53     ` Ben Dooks
2010-05-06  5:53       ` Ben Dooks

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