diff options
Diffstat (limited to 'target/linux/s3c24xx/patches-2.6.24/1006-fix-i2c-s3c2410-resume-race.patch.patch')
| -rw-r--r-- | target/linux/s3c24xx/patches-2.6.24/1006-fix-i2c-s3c2410-resume-race.patch.patch | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/target/linux/s3c24xx/patches-2.6.24/1006-fix-i2c-s3c2410-resume-race.patch.patch b/target/linux/s3c24xx/patches-2.6.24/1006-fix-i2c-s3c2410-resume-race.patch.patch new file mode 100644 index 0000000000..720608ea93 --- /dev/null +++ b/target/linux/s3c24xx/patches-2.6.24/1006-fix-i2c-s3c2410-resume-race.patch.patch @@ -0,0 +1,115 @@ +From d3063c1ec65b37b45e808313133196185ea4901f Mon Sep 17 00:00:00 2001 +From: mokopatches <mokopatches@openmoko.org> +Date: Fri, 4 Apr 2008 11:30:03 +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 | 35 ++++++++++++++++++++++++++++++++++- + 1 files changed, 34 insertions(+), 1 deletions(-) + +diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c +index c44ada5..5ac8309 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); + } + +@@ -282,7 +292,7 @@ static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat) + + case STATE_STOP: + dev_err(i2c->dev, "%s: called in STATE_STOP\n", __FUNCTION__); +- s3c24xx_i2c_disable_irq(i2c); ++ s3c24xx_i2c_disable_irq(i2c); + goto out_ack; + + case STATE_START: +@@ -502,6 +512,14 @@ 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); +@@ -886,6 +904,17 @@ 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); +@@ -893,6 +922,8 @@ static int s3c24xx_i2c_resume(struct platform_device *dev) + if (i2c != NULL) + s3c24xx_i2c_init(i2c); + ++ i2c->suspended--; ++ + return 0; + } + +@@ -905,6 +936,7 @@ 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, +@@ -915,6 +947,7 @@ 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, +-- +1.5.6.5 + |