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| author | Jean Delvare <khali@linux-fr.org> | 2007-11-15 19:24:01 +0100 |
|---|---|---|
| committer | Jean Delvare <khali@hyperion.delvare> | 2007-11-15 19:24:01 +0100 |
| commit | bd4217d8c6ef48425c8d6b28d2e089a83e01af04 (patch) | |
| tree | 0c399bdc4497ced5f168fa224a2c4c5ca63cfb5e /drivers/i2c/i2c-dev.c | |
| parent | i2c-dev: "how does it work" comments (diff) | |
| download | linux-bd4217d8c6ef48425c8d6b28d2e089a83e01af04.tar.xz linux-bd4217d8c6ef48425c8d6b28d2e089a83e01af04.zip | |
i2c-dev: Unbound new-style i2c clients aren't busy
Let i2c-dev deal properly with new-style i2c clients. Instead of
considering them always busy, it needs to check wether a driver is
bound to them or not.
This is still not completely correct, as the client could become
busy later, but the same problem already existed before new-style
clients were introduced. We'll want to fix it someday.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Diffstat (limited to 'drivers/i2c/i2c-dev.c')
| -rw-r--r-- | drivers/i2c/i2c-dev.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index 7360f9c37256..c21ae20ae362 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -182,6 +182,29 @@ static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t c return ret; } +/* This address checking function differs from the one in i2c-core + in that it considers an address with a registered device, but no + bounded driver, as NOT busy. */ +static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) +{ + struct list_head *item; + struct i2c_client *client; + int res = 0; + + mutex_lock(&adapter->clist_lock); + list_for_each(item, &adapter->clients) { + client = list_entry(item, struct i2c_client, list); + if (client->addr == addr) { + if (client->driver) + res = -EBUSY; + break; + } + } + mutex_unlock(&adapter->clist_lock); + + return res; +} + static int i2cdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { @@ -213,8 +236,9 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, if ((arg > 0x3ff) || (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) return -EINVAL; - if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg)) + if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) return -EBUSY; + /* REVISIT: address could become busy later */ client->addr = arg; return 0; case I2C_TENBIT: |