diff options
| author | mokopatches <mokopatches@openmoko.org> | 2008-11-19 17:03:09 +0000 |
|---|---|---|
| committer | warmcat <andy@warmcat.com> | 2008-11-19 17:03:09 +0000 |
| commit | 22eed212f2eb365f1a99b2fbad1ad35379623ec0 (patch) | |
| tree | 0d5ec2e4ab161216e5c0796c3a15b9cc74c85fbb | |
| parent | 6f9153da18b2f9180b4381cff3785e3dba01c7e7 (diff) | |
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>
| -rw-r--r-- | drivers/i2c/busses/i2c-s3c2410.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index ba0006666b3..3a86f23cf44 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -76,6 +76,8 @@ struct s3c24xx_i2c { #ifdef CONFIG_CPU_FREQ struct notifier_block freq_transition; #endif + + int suspended; }; /* default platform data removed, dev should always carry data. */ @@ -135,6 +137,14 @@ 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); } @@ -480,6 +490,14 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, if (i2c->suspended) return -EIO; + 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); @@ -973,6 +991,8 @@ static int s3c24xx_i2c_resume(struct platform_device *dev) i2c->suspended = 0; s3c24xx_i2c_init(i2c); + i2c->suspended--; + return 0; } |