[U-Boot] [PATCH RFC 3/4] ARMV7: OMAP: I2C driver: Restructure i2c_write_byte function

[Heiko Schocher <hs@denx.de>]

Hello Steve,

Steve Sakoman wrote:
> On Wed, 2010-10-20 at 08:08 +0200, Heiko Schocher wrote:
>> Hello Steve,
>>
>> Steve Sakoman wrote:
>>> This patch removes the "magic number" delays and instead
>>> monitors state changes in the status register bits.
>>>
>>> Signed-off-by: Steve Sakoman <steve.sakoman@linaro.org>
>>> ---
>>>  drivers/i2c/omap24xx_i2c.c |   76 +++++++++++++++++++++++--------------------
>>>  1 files changed, 41 insertions(+), 35 deletions(-)
>> After trying this for the omap3_beagle board, I get an
>> compiler warning:
>>
>> [hs at pollux u-boot]$ ./MAKEALL omap3_beagle
>> Configuring for omap3_beagle board...
>> omap24xx_i2c.c: In function 'i2c_write_byte':
>> omap24xx_i2c.c:221: warning: unused variable 'stat'
> 
> Hmm . . . I can swear I fixed that!  Must be getting old :-)

;-)

>>    text    data     bss     dec     hex filename
>>  218103   11412  202384  431899   6971b ./u-boot
>>
>> --------------------- SUMMARY ----------------------------
>> Boards compiled: 1
>> Boards with warnings or errors: 1 ( omap3_beagle )
>> ----------------------------------------------------------
>> [hs at pollux u-boot]$
>>
>> following patch fixes it.
>>
>> BTW:
>> Just for the record, your patchset works fine and faster
>> on the beagle board, for example:
>>
>>                  before your  after your
>>                  patchset     patchset
>> i2c probe        9s           0,4s
>> i2c md 48 0 100  17s          1s
> 
> I'm glad that you see the same speedups!
> 
> What tool do you use to measure the speedups?

You find it here:
ftp://ftp.denx.de/pub/tools/time_log

You can start this script for example with:

kermit -c 2>&1 | ./time_log "start"

and then measure with for example:

echo start;i2c md 48 0 100;echo stop

and you get the time the command(s) between start
and stop needed ...

>> would you post a v2 of this patch, and I add my
>> "Tested-by" to it, or is it OK, if I add my fix patch
>> to u-boot-i2c master?
> 
> I've posted v2 with your "Tested-by" and the warning fix.

Ok, thanks!

bye,
Heiko
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