[FE training-materials-updates] Clarify SMBus explanation

[Michael Opdenacker]

Repository : git://git.free-electrons.com/training-materials.git

On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=b0771676e651ddc33ab26e24679adb334cba85a0

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commit b0771676e651ddc33ab26e24679adb334cba85a0
Author: Michael Opdenacker <michael.opdenacker at free-electrons.com>
Date:   Wed Apr 1 07:12:00 2015 +0200

    Clarify SMBus explanation
    
    Signed-off-by: Michael Opdenacker <michael.opdenacker at free-electrons.com>


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b0771676e651ddc33ab26e24679adb334cba85a0
 slides/kernel-i2c/kernel-i2c.tex | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/slides/kernel-i2c/kernel-i2c.tex b/slides/kernel-i2c/kernel-i2c.tex
index aae2c08..48efab7 100644
--- a/slides/kernel-i2c/kernel-i2c.tex
+++ b/slides/kernel-i2c/kernel-i2c.tex
@@ -310,9 +310,10 @@ error = i2c_transfer(client->adapter, msg, 2);
   \item SMBus is a subset of the I2C protocol.
   \item It defines a standard set of transactions, for example to read
     or write a register into a device.
-  \item Linux provides SMBus functions that {\em should be used} when
-    possible instead of the raw API, if the I2C device uses this
-    standard type of transactions.
+  \item Linux provides SMBus functions that {\em should be used}
+    instead of the raw API, if the I2C device supports this
+    standard type of transactions. The driver can then be used on both
+    SMBus and I2C adapters (can't use I2C commands on SMBus adapters).
   \item Example: the \kfunc{i2c_smbus_read_byte_data} function allows
     to read one byte of data from a device register.
     \begin{itemize}