[U-Boot] [PATCH] mx53loco: Remove unneeded 'retval' variable

[Stefano Babic]

On 27/12/2012 11:35, Wolfgang Denk wrote:
> Dear Fabio Estevam,
> 

Hi Wolfgang,

> In message <1356604017-9699-1-git-send-email-festevam at gmail.com> you wrote:
>> From: Fabio Estevam <fabio.estevam at freescale.com>
>>
>> commit c73368150 (pmic: Extend PMIC framework to support multiple instances 
>> of PMIC devices) introduced an extra 'retval' variable, but this is not 
>> necessary since we have already the variable 'ret' in place.
>>
>> So use 'ret' to store the return values from the pmic related calls and remove
>> 'retval'.
>>
>> Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
> 
> Hm...
> 
> I think the hole error code handling is borked in this function.
> 
> Assume you enter this branch:
> 
> 349
> 350         if (!i2c_probe(CONFIG_SYS_DIALOG_PMIC_I2C_ADDR)) {
> 
> This will set "ret":
> 
> 361                 ret = pmic_reg_write(p, DA9053_BUCKCORE_REG, val);
> 362
> 363                 ret |= pmic_reg_read(p, DA9053_SUPPLY_REG, &val);
> ...
> 365                 ret |= pmic_reg_write(p, DA9053_SUPPLY_REG, val);
> ...
> 368                 ret |= pmic_reg_write(p, DA9053_BUCKPRO_REG, 0x62);
> 369                 ret |= pmic_reg_write(p, DA9053_SUPPLY_REG, 0x62);
> 370         }
> 
> Assume any of these calls returns an error condition.
> 
> Now we enter the second branch:
> 
> 371
> 372         if (!i2c_probe(CONFIG_SYS_FSL_PMIC_I2C_ADDR)) {
> ...
> 

I think it relies on the fact that only one of the two PMICs is mounted
on the board. There are versions of the board with the Dialog PMIC, and
other versions with Frescale's. Worse it is, there is no easy way to
detect which version of the board is running.

However, only one of the two branch can run, because i2c_probe() fails
if the PMIC is not found.

> But here we will unconditionally set "ret", no matter what it
> contained before:
> 
> 384                 ret = pmic_reg_write(p, REG_SW_0, val);

Agree, but physically not possible, until Freescale decides to mount
both PMICs on the mx53loco...(but this is a nonsense)

Best regards,
Stefano Babic

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