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authorOlof Johansson <olof@lixom.net>2012-09-20 19:57:38 -0700
committerOlof Johansson <olof@lixom.net>2012-09-20 19:57:38 -0700
commit32dec75349da4e68b53f099ce3a96469cdc334d6 (patch)
tree96aca7914b07697668ec716a3f80fb8c82e7a971 /drivers/i2c/i2c-core.c
parent740418ef19fd7def7b9c333435d4ca1dce28cc42 (diff)
parent9891e3240543c45176b1298164418b61e8909ed0 (diff)
downloadlinux-32dec75349da4e68b53f099ce3a96469cdc334d6.tar.bz2
Merge tag 'tegra-for-3.7-dmaengine' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra into next/cleanup
ARM: tegra: switch to dmaengine The Tegra code-base has contained both a legacy DMA and a dmaengine driver since v3.6-rcX. This series flips Tegra's defconfig to enable dmaengine rather than the legacy driver, and removes the legacy driver and all client code. * tag 'tegra-for-3.7-dmaengine' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra: ASoC: tegra: remove support of legacy DMA driver based access spi: tegra: remove support of legacy DMA driver based access ARM: tegra: apbio: remove support of legacy DMA driver based access ARM: tegra: dma: remove legacy APB DMA driver ARM: tegra: config: enable dmaengine based APB DMA driver + sync to 3.6-rc6
Diffstat (limited to 'drivers/i2c/i2c-core.c')
-rw-r--r--drivers/i2c/i2c-core.c22
1 files changed, 20 insertions, 2 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 2efa56c5ff2c..2091ae8f539a 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -637,6 +637,22 @@ static void i2c_adapter_dev_release(struct device *dev)
}
/*
+ * This function is only needed for mutex_lock_nested, so it is never
+ * called unless locking correctness checking is enabled. Thus we
+ * make it inline to avoid a compiler warning. That's what gcc ends up
+ * doing anyway.
+ */
+static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
+{
+ unsigned int depth = 0;
+
+ while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
+ depth++;
+
+ return depth;
+}
+
+/*
* Let users instantiate I2C devices through sysfs. This can be used when
* platform initialization code doesn't contain the proper data for
* whatever reason. Also useful for drivers that do device detection and
@@ -726,7 +742,8 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
/* Make sure the device was added through sysfs */
res = -ENOENT;
- mutex_lock(&adap->userspace_clients_lock);
+ mutex_lock_nested(&adap->userspace_clients_lock,
+ i2c_adapter_depth(adap));
list_for_each_entry_safe(client, next, &adap->userspace_clients,
detected) {
if (client->addr == addr) {
@@ -1073,7 +1090,8 @@ int i2c_del_adapter(struct i2c_adapter *adap)
return res;
/* Remove devices instantiated from sysfs */
- mutex_lock(&adap->userspace_clients_lock);
+ mutex_lock_nested(&adap->userspace_clients_lock,
+ i2c_adapter_depth(adap));
list_for_each_entry_safe(client, next, &adap->userspace_clients,
detected) {
dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,