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authorJean Delvare <khali@linux-fr.org>2007-11-15 19:24:01 +0100
committerJean Delvare <khali@hyperion.delvare>2007-11-15 19:24:01 +0100
commitbd4217d8c6ef48425c8d6b28d2e089a83e01af04 (patch)
tree0c399bdc4497ced5f168fa224a2c4c5ca63cfb5e
parent907135aaa0cc120a347222c8f274ecc5ca0db641 (diff)
downloadlinux-stericsson-bd4217d8c6ef48425c8d6b28d2e089a83e01af04.tar.gz
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>
-rw-r--r--drivers/i2c/i2c-dev.c26
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: