[PATCH 1/1 v2] ARM: coresight: fix system halt when etm enable and add nosmp to command line

[Zhi Li]

On Tue, Feb 24, 2015 at 4:00 PM, Mathieu Poirier
<mathieu.poirier at linaro.org> wrote:
> On 19 February 2015 at 06:57,  <Frank.Li at freescale.com> wrote:
>> From: Frank Li <Frank.Li at freescale.com>
>>
>> when nosmp set, only 1 core enabled. try to access disable core will halt.
>> dts need added arm,primecell-periphid =  <id> for none-boot core
>> otherwise amba_device_add will halt when read peripheral id.
>>
>> Signed-off-by: Frank Li <Frank.Li at freescale.com>
>> ---
>> Change from v1 to v2
>>         - fixed typo
>>
>>  drivers/coresight/coresight-etm3x.c | 4 ++++
>>  drivers/coresight/of_coresight.c    | 3 +--
>>  2 files changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/coresight/coresight-etm3x.c b/drivers/coresight/coresight-etm3x.c
>> index 73c3669..d312952 100644
>> --- a/drivers/coresight/coresight-etm3x.c
>> +++ b/drivers/coresight/coresight-etm3x.c
>> @@ -1829,6 +1829,10 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
>>                 return ret;
>>
>>         drvdata->cpu = pdata ? pdata->cpu : 0;
>> +       if (drvdata->cpu < 0) {
>> +               ret = -EINVAL;
>> +               goto err_arch_supported;
>> +       }
>>
>>         get_online_cpus();
>>         etmdrvdata[drvdata->cpu] = drvdata;
>> diff --git a/drivers/coresight/of_coresight.c b/drivers/coresight/of_coresight.c
>> index c3efa41..6804bbd 100644
>> --- a/drivers/coresight/of_coresight.c
>> +++ b/drivers/coresight/of_coresight.c
>> @@ -196,8 +196,7 @@ struct coresight_platform_data *of_get_coresight_platform_data(
>>                 if (cell) {
>>                         hwid = of_read_number(cell, of_n_addr_cells(dn));
>>                         index = get_logical_index(hwid);
>> -                       if (index != -EINVAL)
>> -                               pdata->cpu = index;
>> +                       pdata->cpu = index;
>>                 }
>>         }
>>
>> --
>> 1.9.1
>>
>
> Frank,
>
> Thanks for your submission - this is a valid scenario.  On the flip
> side things have changed in "of_get_coresight_platform_data()" and
> your patch's logic doesn't apply.  Go look at my next branch [1] - we
> are now using "of_get_cpu_node()" so that things work on 64-bit
> implementations.

Okay I will rebase to you next branch.

>
> Keep what you've done in "etm_probe()" but you will have to re-work
> the other part - meddling with "cpu_online()" would be my first
> choice...

of_get_cpu_node may return NULL if core is not exist. I will test it
when I get hardware.
pdata->cpu will always return 0 if nosmp.

>
> Lastly please improve the commit log.  Adding a peripheral ID in the
> DTS will indeed prevent AMBA from proving a non-responsive memory area
> but it is not the point of the patch itself.

Our imx7 just come out.  dts part have not upstream yet.
So I just sent out coresight part change.

>
> Thanks,
> Mathieu
>
> [1]. https://git.linaro.org/kernel/coresight.git/shortlog/refs/heads/next