On 3/8/2022 9:52 pm, Heinz Junkes wrote:
> We had a problem initialising the i2c devices on the MVME3100.
> Unfortunately, I still don't understand the order of initialisation.
>
> However, the direct driver initialisation from bspstart no longer worked as
> it did with older versions.
>
> My workaround therefore looks like this:
>
> rtems@rtems-dev:~/MVME3100/kernel$ git diff
> bsps/powerpc/mvme3100/start/bspstart.c
> diff --git a/bsps/powerpc/mvme3100/start/bspstart.c
> b/bsps/powerpc/mvme3100/start/bspstart.c
> index 0ec215e33b..96d6e2f9cd 100644
> --- a/bsps/powerpc/mvme3100/start/bspstart.c
> +++ b/bsps/powerpc/mvme3100/start/bspstart.c
> @@ -52,6 +52,8 @@
> extern unsigned long __rtems_end[];
> extern unsigned ppc_exc_lock_std, ppc_exc_gpr3_std;
>
> +extern bool _IO_All_drivers_initialized;
> +
> /*
> * Copy Additional boot param passed by boot loader
> */
> @@ -419,7 +421,14 @@ void bsp_start( void )
>
> static void mvme3100_i2c_initialize(void)
> {
> + printk("-------- call BSP_i2c_initialize() with
> _IO_All_drivers_initialized = true\n");
> + /*
> + * we need the drivers registered as they appear, due to get
> + * the i2c devices ready
> + */
> + _IO_All_drivers_initialized = true;
> BSP_i2c_initialize();
> + _IO_All_drivers_initialized = false;
> }
Where is this being called? I cannot see it in the patch. If it is BSP start I
think it is too early to make these calls.
> RTEMS_SYSINIT_ITEM(
>
>
> You can find this in cpukit/sapi/src/ioregisterdriver.c:
>
>
> if ( _IO_All_drivers_initialized ) {
> /* Other drivers have already been initialized, we initialize
> * the driver directly.
> */
> return rtems_io_initialize( major, 0, NULL );
> } else {
> /* The driver will be initialized together with all other drivers
> * in a later stage by _IO_Initialize_all_drivers().
> */
> return RTEMS_SUCCESSFUL;
> }
>
>
> I can imagine that this is not an elegant way, but it's the best I could do.
> Is there any idea how to do it "right"?
> Or should I submit this patch?
I suspect touching that internal variable is not great. That variable could go
away or be made static.
There maybe another BSP hook that could be used or a SYSINIT hook maybe be
needed.
Chris
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