Hi Jean -
Thanks for the new patches. I tested them and they appear to work.
However, the problem with dev_dbg message prefixes early in driver
initialisation is still there:
i2c-elektor: found cy82c693, config register 0x47 = 0xe1
i2c-elektor: found API UP2000 like board, will probe PCF8584 later
i2c-elektor: registers 0xe0000 remapped to fffffd00000e0000
: Write fffffd00000e0001 0x80
: Read fffffd00000e0001 0x00
: Write fffffd00000e0000 0x55
: Read fffffd00000e0000 0x55
: Write fffffd00000e0001 0xA0
: Read fffffd00000e0001 0x20
: Write fffffd00000e0000 0x18
: Read fffffd00000e0000 0xF8
: Write fffffd00000e0001 0xC1
: Read fffffd00000e0001 0x81
i2c-algo-pcf.o: deteted and initialized PCF8584.
i2c_adapter i2c-0: Registered as minor 0
i2c_adapter i2c-0: registered as adapter #0
i2c_adapter i2c-0: found device at 0xe0000
We don't get the driver name until we call i2c_add_adapter in
i2c-algo-pcf.c. Should we revert the dev_dbg statements to pr_debugs
for device byte read/writes? That doesn't sound very consistent
though...
>> * Jean: use of val & 255 in printk statement in pcf_isa_setbyte() - I
>> think this is actually required because parameter val is an integer
>> quantity and could have been sign-extended? I would prefer to change
>> the function parameter to u8, but this violates the types of struct
>> i2c_algo_pcf_data.
>
> The "& 255" is done in the debug printk only, iowrite8 is still called
> with val unmasked, so if the masking actually did something, something
> bas is happening, and the debug trace won't ever show it.
>
> Looking at i2c-algo-pcf, it's quite clear that val will always fit in
> an u8, so the masking is actually needless.
Perhaps the author's original intention would have been better
described by casting val as (u8)val. This avoids any sign-extended
mangling from implicit size conversions, like this one:
char val=0x80;
printf("Write 0x%02X\n", val);
As you say, it doesn't matter for this case because our only caller
(i2c-algo-pcf) does not generate arguments to pcf_isa_setbyte in this
way.
Best wishes,
Stig
