[PATCHv2] mfd: twl4030: clarify the return value for read and write

From: Amit Kucheria
Date: Wed Dec 02 2009 - 09:01:21 EST


Infact, we can just return -1 so that caller knows for sure that all messages
were not tranferred. Please consider fixed patch instead.

We should be checking if all the messages were tranferred or not. And return
-1 for failure. Currently we return success (0) even if none of messages were
transferred successfully.

Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxxxxx>
---
drivers/mfd/twl4030-core.c | 25 +++++++++++++++++--------
1 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/drivers/mfd/twl4030-core.c b/drivers/mfd/twl4030-core.c
index 56f1de5..8f9ba79 100644
--- a/drivers/mfd/twl4030-core.c
+++ b/drivers/mfd/twl4030-core.c
@@ -292,10 +292,14 @@ int twl4030_i2c_write(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes)
ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 1);
mutex_unlock(&twl->xfer_lock);

- /* i2cTransfer returns num messages.translate it pls.. */
- if (ret >= 0)
- ret = 0;
- return ret;
+ /* i2c_transfer returns number of messages transferred */
+ if (ret != 1) {
+ pr_err("%s: i2c_write failed to transfer all messages\n",
+ DRIVER_NAME);
+ return -1;
+ } else {
+ return 0;
+ }
}
EXPORT_SYMBOL(twl4030_i2c_write);

@@ -344,10 +348,15 @@ int twl4030_i2c_read(u8 mod_no, u8 *value, u8 reg, unsigned num_bytes)
ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 2);
mutex_unlock(&twl->xfer_lock);

- /* i2cTransfer returns num messages.translate it pls.. */
- if (ret >= 0)
- ret = 0;
- return ret;
+ /* i2c_transfer returns number of messages transferred */
+ if (ret != 2) {
+ pr_err("%s: i2c_read failed to transfer all messages\n",
+ DRIVER_NAME);
+ return -1;
+ }
+ else {
+ return 0;
+ }
}
EXPORT_SYMBOL(twl4030_i2c_read);

--
1.6.3.3

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