[PATCH RFT 1/2] drivers: bus: check cci device tree node status
kesavan.abhilash at gmail.com
Tue Dec 9 20:25:53 PST 2014
On Wed, Dec 10, 2014 at 9:44 AM, Sudeep Holla <sudeep.holla at arm.com> wrote:
> Hi Abhilash,
> On Wednesday 10 December 2014 09:31 AM, Abhilash Kesavan wrote:
>> On Fri, Nov 28, 2014 at 8:20 PM, Abhilash Kesavan <a.kesavan at samsung.com>
>>> The arm-cci driver completes the probe sequence even if the cci node is
>>> marked as disabled. Add a check in the driver to honour the cci status
>>> in the device tree.
>>> Signed-off-by: Abhilash Kesavan <a.kesavan at samsung.com>
>> This patch helps disable CCI on the Arndale Octa board thus resolving
>> some imprecise aborts seen on that board. Kindly review.
>>> drivers/bus/arm-cci.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>> diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
>>> index 860da40..0ce5e2d 100644
>>> --- a/drivers/bus/arm-cci.c
>>> +++ b/drivers/bus/arm-cci.c
>>> @@ -1312,6 +1312,9 @@ static int cci_probe(void)
>>> if (!np)
>>> return -ENODEV;
>>> + if (!of_device_is_available(np))
>>> + return -ENODEV;
> IIUC, by this change you are disabling the MCPM boot protocol here.
> Is there any alternative boot protocol that works on this platform
> to boot all 8 cores ? Sorry by quick grep couldn't find one, hence
> so I am asking.
Thanks for the reply.
On disabling MCPM, we will default to platsmp.c/firmware.c which boots
4 cores as per Kevin's comment here. This was the original behavior
before MCPM was enabled for all 5420 based SoCs.
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