Re: [PATCH] i2c: change the id to let the i2c device work

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On 10/12/2012 13:14, Mark Brown wrote:
On Fri, Oct 12, 2012 at 12:57:34PM +0800, Bo Shen wrote:
On 10/12/2012 12:40, Mark Brown wrote:
On Fri, Oct 12, 2012 at 10:34:18AM +0800, Bo Shen wrote:

As the old method will use platform device id, change the id to
let the i2c device work

What are "the old method" and new method?  You're not explaining why
this is needed...

Maybe use the 'legacy method' will be better (I am not sure). Now,
the Linux kernel is transferring to device tree which doesn't use
platform device id. So, change the id to let the legacy code work.

May you understand.

No, this still makes no sense to me.  This is clearly a non-DT device
registration, what does DT have to do with anything here?  What is the

Yes, this is non-DT device registration.
As the Linux kernel code is transferring to DT which doesn't use platform device id. however here, modified unconsciously. So correct this error.

practical problem you are seeing in your system and how does this help
with it?

In non-DT kernel, we use platform device id to distinguish between each device.

For example,
if register i2c device on i2c bus 0, using:
  i2c_register_board_info(0, ...)
if register i2c device on i2c bus 1, using:
  i2c_register_board_info(1, ...)

So, in this case, if the id = -1, i2c core will dynamically assign a bus id to this bus when running, the dynamically assigned bus id is unknown when writing the code. So, when we use i2c_register_board_info(int busnum, ...) to register device on busnum. we don't know which value to be use.

So, this patch will fix this issue.


BRs,
Bo Shen
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