On Fri, Dec 11, 2009 at 12:53:45PM +0200, Eduardo Valentin wrote:
> On Fri, Dec 11, 2009 at 11:36:10AM +0100, ext Samuel Ortiz wrote:
> > Hi Amit,
> >
> > On Mon, Dec 07, 2009 at 03:53:09PM +0200, Eduardo Valentin wrote:
> > > On Mon, Dec 07, 2009 at 01:17:29PM +0100, ext Amit Kucheria wrote:
> > > > Infact, we can just return -EIO 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 | 24 ++++++++++++++++--------
> > > > 1 files changed, 16 insertions(+), 8 deletions(-)
> > > >
> > > > diff --git a/drivers/mfd/twl4030-core.c b/drivers/mfd/twl4030-core.c
> > > > index 56f1de5..3d2c413 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 -EIO;
> > >
> > > How about reporting the actual error that has occurred and reported by i2c_transfer?
> > > Instead of just masking it as EIO? If i2c_transfer returns something > 0 then EIO should be right.
> > > But if returns and error code, then that error code must be reported to upper layers.
> > >
> > So, I applied a modified version of this patch, see below. If you disagree
> > with it, please let me know and I wont push it upstream.
> >
>
> OK.
>
> >
> > commit 8aa7cfd5732dee80aaaf3caa0a1d2f9621126315
> > Author: Amit Kucheria <amit.kucheria@xxxxxxxxxxxxx>
> > Date: Fri Dec 11 11:31:11 2009 +0100
> >
> > mfd: Clarify twl4030 return value for read and write
> >
> > We should be checking if all the messages were tranferred. If not, then we
> > should propagate the i2c core error code.
> > Currently we return success (0) even if none of messages were transferred
> > successfully.
> >
> > Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxxxxx>
> > Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>
> >
> > diff --git a/drivers/mfd/twl4030-core.c b/drivers/mfd/twl4030-core.c
> > index e4a5d48..8add16c 100644
> > --- a/drivers/mfd/twl4030-core.c
> > +++ b/drivers/mfd/twl4030-core.c
> > @@ -306,10 +306,14 @@ 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 ret;
>
> For this case we will be returning success if i2c_transfer fails to transfer the one message.
> I guess we should return ret only if ret < 0 ? otherwise -EIO.
Yes, that's correct, fixed now.
Cheers,
Samuel.
> > + } else {
> > + return 0;
> > + }
> > }
> > EXPORT_SYMBOL(twl4030_i2c_write);
> >
> > @@ -358,10 +362,14 @@ 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 ret;
>
> Same case here, we will be returning success if i2c_transfer fails to transfer any of those messages.
> I guess we should return ret only if ret < 0 ? otherwise -EIO.
>
>
> > + } else {
> > + return 0;
> > + }
> > }
> > EXPORT_SYMBOL(twl4030_i2c_read);
> >
> > --
> > Intel Open Source Technology Centre
> > http://oss.intel.com/
>
> --
> Eduardo Valentin
--
Intel Open Source Technology Centre
http://oss.intel.com/
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