i2c: core: use I2C locking behaviour also for SMBUS

If I2C transfers are executed in atomic contexts, trylock is used
instead of lock. This behaviour was missing for SMBUS, although a lot of
transfers are of SMBUS type, either emulated or direct. So, factor out
the locking routine into a helper and use it for I2C and SMBUS.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index f8502064cd6b4450c0948e0cab8600f5618d8b68..ad14f38a67e4ac91862948c1ae5ae9ab1d835de2 100644 (file)
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1946,14 +1946,9 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
         *    one (discarding status on the second message) or errno
         *    (discarding status on the first one).
         */
-       if (i2c_in_atomic_xfer_mode()) {
-               ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT);
-               if (!ret)
-                       /* I2C activity is ongoing. */
-                       return -EAGAIN;
-       } else {
-               i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
-       }
+       ret = __i2c_lock_bus_helper(adap);
+       if (ret)
+               return ret;
 
        ret = __i2c_transfer(adap, msgs, num);
        i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);

diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index 1321191125965a9f5ef6c1b684ff29641a24496a..357e083e8f450cec0fbe27636676f1c80a97dec5 100644 (file)
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -20,6 +20,8 @@
 #include <linux/i2c-smbus.h>
 #include <linux/slab.h>
 
+#include "i2c-core.h"
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/smbus.h>
 
@@ -530,7 +532,10 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 {
        s32 res;
 
-       i2c_lock_bus(adapter, I2C_LOCK_SEGMENT);
+       res = __i2c_lock_bus_helper(adapter);
+       if (res)
+               return res;
+
        res = __i2c_smbus_xfer(adapter, addr, flags, read_write,
                               command, protocol, data);
        i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT);

diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
index 9d8526415b2649728e3d86d39682ba1c36fb53a4..deea47c576e50c7ca6107f632bd215d564d376b2 100644 (file)
--- a/drivers/i2c/i2c-core.h
+++ b/drivers/i2c/i2c-core.h
@@ -39,6 +39,18 @@ static inline bool i2c_in_atomic_xfer_mode(void)
        return system_state > SYSTEM_RUNNING && irqs_disabled();
 }
 
+static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
+{
+       int ret = 0;
+
+       if (i2c_in_atomic_xfer_mode())
+               ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
+       else
+               i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
+
+       return ret;
+}
+
 #ifdef CONFIG_ACPI
 const struct acpi_device_id *
 i2c_acpi_match_device(const struct acpi_device_id *matches,