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

["Mylene Josserand" <Mylene.Josserand@navocap.com>]

Hi Marc Kleine-Budde,

It is again you who answers my questions :) Thank you again for your help.

Le 10/04/2013 15:39, Marc Kleine-Budde a écrit :
> On 04/10/2013 03:07 PM, Mylene Josserand wrote:
>> When I compile the driver in static, the kernel stopped booting. With
>> some printk, the driver is blocked at the function "spi_write" of the
>> function "mcp251x_hw_reset". The dmesg with my outputs :
>>
>> "
>> spi_imx imx27-cspi.0: master is unqueued, this is deprecated
>> spi_imx imx27-cspi.0: probed
>> CAN device driver interface
>> mcp251x_can_init
>> mcp251x_clean
>> mcp251x_can_probe
>> mcp251x_hw_probe
>> mcp251x_hw_reset
>> mcp251x_hw_reset : spi_write : start
>> "
>
> Does it hang here?
>
> http://lxr.linux.no/linux+v3.8.6/drivers/net/can/mcp251x.c#L624

Yes it hangs here. It did not print "reset failed: ret = X" or anything 
else.

>
> Is this the first spi transfer that occurs in the driver?

I think yes. It is the first time MCP251x uses spi transfer function.

>
>> I thought that it was a spi problem because of the warning "master is
>> unqueued, this is deprecated" but in fact the spi works.
>> One surprising thing (for me) is that the MCP251x compiled in module is
>> probed ! (I did not test it yet)
>
> 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.

>
> Marc
>

Best regards,


-- 
Mylène JOSSERAND
Navocap