Re: [imx27 - mcp251x] MCP251x does not work in static ?

[Marc Kleine-Budde <mkl@pengutronix.de>]

[-- Attachment #1: Type: text/plain, Size: 1454 bytes --]

On 04/10/2013 04:11 PM, Mylene Josserand wrote:

>> If it's the first spi transfer in the driver that hangs and if the
>> mcp251x works if loaded as a module, there is probably some
>> initialisation missing. Look for stuff that gets initialized after the
>> mcp251x would have been loaded if compiled into the kernel. Make a
>> "diff" between the bootload with mcp251x compiled into the kernel and
>> without. Other usual suspects are: clocks, pinmux (spi _and_ the mcp251x
>> dedicated IRQ line), gpio setup.
> 
> Thanks for the advice and the ideas to look at ! I have already compared 
> the bootload and I have seen no differences (maybe I will check that 
> another time). I will search about clocks, pinmux and gpio setup and I 
> will update you if I found how to fix that.

Save the bootlog of a system start with the driver compiled as a module
into file bootlog-module.txt. Make a second bootlog with the driver
compiled into the kernel, save as bootlog-builtin.txt. Then:

    diff -u bootlog-module.txt bootlog-builtin.txt

Look for the stuff that would have been initialized _after_ the system
hangs. The diff should show you this.

Marc

-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 263 bytes --]