107 lines
3.1 KiB
Diff
Executable File
107 lines
3.1 KiB
Diff
Executable File
From eb5cadc7ff0e6c3aedfec3323146d7bb6bdfe0f0 Mon Sep 17 00:00:00 2001
|
|
From: mokopatches <mokopatches@openmoko.org>
|
|
Date: Wed, 16 Jul 2008 14:44:10 +0100
|
|
Subject: [PATCH] fix-i2c-s3c2410-resume-race.patch
|
|
fix-i2c-s3c2410-resume-race.patch
|
|
|
|
There is a nasty race between i2c-s3c2410 resume and resume of I2C
|
|
driver and the client drivers -- the watchdog device actually gets to
|
|
use the dead I2C bus before it is reinitialized by the I2C driver
|
|
resume! This patch makes sure any customers get turned away until
|
|
the shopkeeper has woken up.
|
|
|
|
Signed-off-by: Andy Green <andy@openmoko.com>
|
|
---
|
|
drivers/i2c/busses/i2c-s3c2410.c | 33 +++++++++++++++++++++++++++++++++
|
|
1 files changed, 33 insertions(+), 0 deletions(-)
|
|
|
|
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
|
|
index 9e8c875..02459d7 100644
|
|
--- a/drivers/i2c/busses/i2c-s3c2410.c
|
|
+++ b/drivers/i2c/busses/i2c-s3c2410.c
|
|
@@ -71,6 +71,8 @@ struct s3c24xx_i2c {
|
|
struct resource *irq;
|
|
struct resource *ioarea;
|
|
struct i2c_adapter adap;
|
|
+
|
|
+ int suspended;
|
|
};
|
|
|
|
/* default platform data to use if not supplied in the platform_device
|
|
@@ -156,6 +158,14 @@ static inline void s3c24xx_i2c_disable_irq(struct s3c24xx_i2c *i2c)
|
|
unsigned long tmp;
|
|
|
|
tmp = readl(i2c->regs + S3C2410_IICCON);
|
|
+
|
|
+/* S3c2442 datasheet
|
|
+ *
|
|
+ * If the IICCON[5]=0, IICCON[4] does not operate correctly.
|
|
+ * So, It is recommended that you should set IICCON[5]=1,
|
|
+ * although you does not use the IIC interrupt.
|
|
+ */
|
|
+
|
|
writel(tmp & ~S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
|
|
}
|
|
|
|
@@ -501,6 +511,14 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int
|
|
unsigned long timeout;
|
|
int ret;
|
|
|
|
+ if (i2c->suspended) {
|
|
+ dev_err(i2c->dev,
|
|
+ "Hey I am still asleep (suspended: %d), retry later\n",
|
|
+ i2c->suspended);
|
|
+ ret = -EAGAIN;
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
ret = s3c24xx_i2c_set_master(i2c);
|
|
if (ret != 0) {
|
|
dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
|
|
@@ -885,6 +903,17 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev)
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
+
|
|
+static int s3c24xx_i2c_suspend(struct platform_device *dev, pm_message_t state)
|
|
+{
|
|
+ struct s3c24xx_i2c *i2c = platform_get_drvdata(dev);
|
|
+
|
|
+ if (i2c != NULL)
|
|
+ i2c->suspended++;
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
static int s3c24xx_i2c_resume(struct platform_device *dev)
|
|
{
|
|
struct s3c24xx_i2c *i2c = platform_get_drvdata(dev);
|
|
@@ -892,6 +921,8 @@ static int s3c24xx_i2c_resume(struct platform_device *dev)
|
|
if (i2c != NULL)
|
|
s3c24xx_i2c_init(i2c);
|
|
|
|
+ i2c->suspended--;
|
|
+
|
|
return 0;
|
|
}
|
|
|
|
@@ -904,6 +935,7 @@ static int s3c24xx_i2c_resume(struct platform_device *dev)
|
|
static struct platform_driver s3c2410_i2c_driver = {
|
|
.probe = s3c24xx_i2c_probe,
|
|
.remove = s3c24xx_i2c_remove,
|
|
+ .suspend = s3c24xx_i2c_suspend,
|
|
.resume = s3c24xx_i2c_resume,
|
|
.driver = {
|
|
.owner = THIS_MODULE,
|
|
@@ -914,6 +946,7 @@ static struct platform_driver s3c2410_i2c_driver = {
|
|
static struct platform_driver s3c2440_i2c_driver = {
|
|
.probe = s3c24xx_i2c_probe,
|
|
.remove = s3c24xx_i2c_remove,
|
|
+ .suspend = s3c24xx_i2c_suspend,
|
|
.resume = s3c24xx_i2c_resume,
|
|
.driver = {
|
|
.owner = THIS_MODULE,
|
|
--
|
|
1.5.6.3
|
|
|