Hi Graham,
while trying to understand why i2c is not working I think there is
something wrong with both my original - and probably with your patch.
For example
http://tomoyo.sourceforge.jp/cgi-bin/lxr/source/drivers/i2c/busses/i2c-at91.c
uses the if(ret) return ret; variant like the original. But their
xfer_read() and xfer_write() functions have a different return value
semantics. They either return 0 if transfer is complete or -ETIMEDOUT.
Nothing else.
The JZ version (at least the one I have in my project):
- returns -ENODEV on timeout
- otherwise returns how many bytes have NOT been transferred (is 0 if
ok but positive else)
So your condition can never be true but the original one also returns
a bad value from i2c_jz_xfer (if # of bytes remaining is > 0). It
should just return the number of successful messages.
Maybe
if (i2c_get_data(buf, 0) < 0)
break;
should better be a
if (i2c_get_data(buf, 0) < 0)
goto L_timeout;
What do you think?
Nikolaus
Am 04.05.2010 um 08:31 schrieb Graham Gower:
ret = xfer_write(pmsg->addr, pmsg->buf,
pmsg->len);
}
- if (ret)
- return ret;
+ if (ret != pmsg->len)
+ return -1;
/* Wait until transfer is finished */
}
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