Re: [PATCH] ARM: OMAP2+: hwmod: check for module address space during init

[Nishanth Menon <nm@ti.com>]

On 10/03/2013 11:59 AM, Suman Anna wrote:
> The hwmod init sequence involves initializing and idling all the
> hwmods during bootup. If a module class has sysconfig, the init
> sequence utilizes the module register base for performing any
> sysc configuration.
> 
> The module address space is being removed from hwmod database and
> retrieved from the <reg> property of the corresponding DT node.
> If a hwmod does not have its corresponding DT node defined and the
> memory address space is not defined in the corresponding
> omap_hwmod_ocp_if, then the module register target address space
> would be NULL and any sysc programming would result in a NULL
> pointer dereference and a kernel boot hang.
> 
> Handle this scenario by checking for a valid module address space
> during the _init of each hwmod, and leaving it in the registered
> state if no module register address base is defined in either of
> the hwmod data or the DT data.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
> This patch helps break the dependencies between hwmod entries and
> corresponding DT entries (especially on OMAP5, where most of the
> address spaces are already cleaned up and the current data files
> have minimal entries) and fixes any boot issues due to missing
> addresses. See for reference,
> http://marc.info/?t=138005421400003&r=1&w=2
> 
> Tested on BeagleXM, Panda4, BeagleBone Black and Panda5 using
> Tero's v7 clk DT patches and Benoit's for-3.13/dts on top of
> 3.12-rc3
> 
>  arch/arm/mach-omap2/omap_hwmod.c | 29 +++++++++++++++++++----------
>  1 file changed, 19 insertions(+), 10 deletions(-)

Mandatory to have this patch for OMAP5uEVM to boot after Tero's v7 [1]
series is merged else the delta between dts and hwmod entries cause
OMAP5 platforms to croak and die - at least worked around as seen in
[2] :(

Tested-by: Nishanth Menon <nm@ti.com>

[1] http://marc.info/?t=138009899400001&r=1&w=2
[2] OMAP5uEVM: http://pastebin.com/jtEMwTY5

-- 
Regards,
Nishanth Menon