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path: root/drivers/i2c/i2c-core.c
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Diffstat (limited to 'drivers/i2c/i2c-core.c')
-rw-r--r--drivers/i2c/i2c-core.c43
1 files changed, 27 insertions, 16 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 85e2e919d1c..5ed622ee65c 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -29,7 +29,6 @@
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/idr.h>
-#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/completion.h>
#include <linux/hardirq.h>
@@ -451,16 +450,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
mutex_lock(&core_lock);
- /* Add the adapter to the driver core.
- * If the parent pointer is not set up,
- * we add this adapter to the host bus.
- */
- if (adap->dev.parent == NULL) {
- adap->dev.parent = &platform_bus;
- pr_debug("I2C adapter driver [%s] forgot to specify "
- "physical device\n", adap->name);
- }
-
/* Set default timeout to 1 second if not already set */
if (adap->timeout == 0)
adap->timeout = HZ;
@@ -1022,7 +1011,8 @@ module_exit(i2c_exit);
*/
int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
- int ret;
+ unsigned long orig_jiffies;
+ int ret, try;
/* REVISIT the fault reporting model here is weak:
*
@@ -1060,7 +1050,15 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
mutex_lock_nested(&adap->bus_lock, adap->level);
}
- ret = adap->algo->master_xfer(adap,msgs,num);
+ /* Retry automatically on arbitration loss */
+ orig_jiffies = jiffies;
+ for (ret = 0, try = 0; try <= adap->retries; try++) {
+ ret = adap->algo->master_xfer(adap, msgs, num);
+ if (ret != -EAGAIN)
+ break;
+ if (time_after(jiffies, orig_jiffies + adap->timeout))
+ break;
+ }
mutex_unlock(&adap->bus_lock);
return ret;
@@ -1509,7 +1507,7 @@ struct i2c_adapter* i2c_get_adapter(int id)
struct i2c_adapter *adapter;
mutex_lock(&core_lock);
- adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id);
+ adapter = idr_find(&i2c_adapter_idr, id);
if (adapter && !try_module_get(adapter->owner))
adapter = NULL;
@@ -1995,14 +1993,27 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
char read_write, u8 command, int protocol,
union i2c_smbus_data *data)
{
+ unsigned long orig_jiffies;
+ int try;
s32 res;
flags &= I2C_M_TEN | I2C_CLIENT_PEC;
if (adapter->algo->smbus_xfer) {
mutex_lock(&adapter->bus_lock);
- res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
- command, protocol, data);
+
+ /* Retry automatically on arbitration loss */
+ orig_jiffies = jiffies;
+ for (res = 0, try = 0; try <= adapter->retries; try++) {
+ res = adapter->algo->smbus_xfer(adapter, addr, flags,
+ read_write, command,
+ protocol, data);
+ if (res != -EAGAIN)
+ break;
+ if (time_after(jiffies,
+ orig_jiffies + adapter->timeout))
+ break;
+ }
mutex_unlock(&adapter->bus_lock);
} else
res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,