Re: [PATCH v2 17/17] ARM: dts: tegra30: cardhu-a04: Add CPU Operating Performance Points

From: Jon Hunter
Date: Fri Nov 15 2019 - 07:52:18 EST


On 13/11/2019 13:57, Dmitry Osipenko wrote:
> Hello Jon,
>
> 13.11.2019 09:52, Jon Hunter ÐÐÑÐÑ:
>>
>> On 24/10/2019 23:14, Dmitry Osipenko wrote:
>>> Utilize common Tegra30 CPU OPP table. CPU DVFS is available now on
>>> cardhu-a04.
>>>
>>> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
>>> ---
>>> arch/arm/boot/dts/tegra30-cardhu-a04.dts | 24 ++++++++++++++++++++++++
>>> 1 file changed, 24 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/tegra30-cardhu-a04.dts b/arch/arm/boot/dts/tegra30-cardhu-a04.dts
>>> index 0d71925d4f0b..9234988624ec 100644
>>> --- a/arch/arm/boot/dts/tegra30-cardhu-a04.dts
>>> +++ b/arch/arm/boot/dts/tegra30-cardhu-a04.dts
>>> @@ -2,6 +2,8 @@
>>> /dts-v1/;
>>>
>>> #include "tegra30-cardhu.dtsi"
>>> +#include "tegra30-cpu-opp.dtsi"
>>> +#include "tegra30-cpu-opp-microvolt.dtsi"
>>>
>>> /* This dts file support the cardhu A04 and later versions of board */
>>>
>>> @@ -127,4 +129,26 @@
>>> nvidia,tegra-core-regulator;
>>> };
>>> };
>>> +
>>> + cpus {
>>> + cpu0: cpu@0 {
>>> + cpu-supply = <&vddctrl_reg>;
>>> + operating-points-v2 = <&cpu0_opp_table>;
>>> + };
>>> +
>>> + cpu@1 {
>>> + cpu-supply = <&vddctrl_reg>;
>>> + operating-points-v2 = <&cpu0_opp_table>;
>>> + };
>>> +
>>> + cpu@2 {
>>> + cpu-supply = <&vddctrl_reg>;
>>> + operating-points-v2 = <&cpu0_opp_table>;
>>> + };
>>> +
>>> + cpu@3 {
>>> + cpu-supply = <&vddctrl_reg>;
>>> + operating-points-v2 = <&cpu0_opp_table>;
>>> + };
>>> + };
>>> };
>>
>> Sorry for not testing this sooner, but this is generating the
>> following WARNING on boot ...
>>
>> [ 2.916019] ------------[ cut here ]------------
>> [ 2.920669] WARNING: CPU: 2 PID: 1 at /dvs/git/dirty/git-master_l4t-upstream/kernel/drivers/opp/of.c:688 _of_add_opp_table_v2.part.2+0x45c/0x4d4
>> [ 2.933713] Modules linked in:
>> [ 2.936785] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc7-next-20191112-gfc6d6db1df2c #1
>> [ 2.945403] Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
>> [ 2.951706] [<c0112924>] (unwind_backtrace) from [<c010c9d0>] (show_stack+0x10/0x14)
>> [ 2.959467] [<c010c9d0>] (show_stack) from [<c0aa4494>] (dump_stack+0xc0/0xd4)
>> [ 2.966707] [<c0aa4494>] (dump_stack) from [<c0124750>] (__warn+0xe0/0xf8)
>> [ 2.973593] [<c0124750>] (__warn) from [<c0124818>] (warn_slowpath_fmt+0xb0/0xb8)
>> [ 2.981090] [<c0124818>] (warn_slowpath_fmt) from [<c0754be0>] (_of_add_opp_table_v2.part.2+0x45c/0x4d4)
>> [ 2.990583] [<c0754be0>] (_of_add_opp_table_v2.part.2) from [<c0754c98>] (dev_pm_opp_of_add_table+0x40/0x15c)
>> [ 3.000508] [<c0754c98>] (dev_pm_opp_of_add_table) from [<c0754de8>] (dev_pm_opp_of_cpumask_add_table+0x34/0xb4)
>> [ 3.010704] [<c0754de8>] (dev_pm_opp_of_cpumask_add_table) from [<c075b058>] (cpufreq_init+0xf8/0x2cc)
>> [ 3.020024] [<c075b058>] (cpufreq_init) from [<c0758758>] (cpufreq_online+0x260/0x824)
>> [ 3.027953] [<c0758758>] (cpufreq_online) from [<c0758d98>] (cpufreq_add_dev+0x6c/0x78)
>> [ 3.035976] [<c0758d98>] (cpufreq_add_dev) from [<c05b3188>] (subsys_interface_register+0xa0/0xec)
>> [ 3.044951] [<c05b3188>] (subsys_interface_register) from [<c07574d4>] (cpufreq_register_driver+0x14c/0x20c)
>> [ 3.054792] [<c07574d4>] (cpufreq_register_driver) from [<c075aee0>] (dt_cpufreq_probe+0x94/0x114)
>> [ 3.063771] [<c075aee0>] (dt_cpufreq_probe) from [<c05b6a88>] (platform_drv_probe+0x48/0x98)
>> [ 3.072225] [<c05b6a88>] (platform_drv_probe) from [<c05b4a38>] (really_probe+0x234/0x34c)
>> [ 3.080502] [<c05b4a38>] (really_probe) from [<c05b4cc8>] (driver_probe_device+0x60/0x168)
>> [ 3.088780] [<c05b4cc8>] (driver_probe_device) from [<c05b4f78>] (device_driver_attach+0x58/0x60)
>> [ 3.097664] [<c05b4f78>] (device_driver_attach) from [<c05b5000>] (__driver_attach+0x80/0xbc)
>> [ 3.106200] [<c05b5000>] (__driver_attach) from [<c05b2db0>] (bus_for_each_dev+0x74/0xb4)
>> [ 3.114389] [<c05b2db0>] (bus_for_each_dev) from [<c05b3da4>] (bus_add_driver+0x164/0x1e8)
>> [ 3.122666] [<c05b3da4>] (bus_add_driver) from [<c05b5b54>] (driver_register+0x7c/0x114)
>> [ 3.130774] [<c05b5b54>] (driver_register) from [<c010306c>] (do_one_initcall+0x54/0x2a8)
>> [ 3.138974] [<c010306c>] (do_one_initcall) from [<c0f01040>] (kernel_init_freeable+0x14c/0x1e8)
>> [ 3.147695] [<c0f01040>] (kernel_init_freeable) from [<c0abbe88>] (kernel_init+0x8/0x10c)
>> [ 3.155887] [<c0abbe88>] (kernel_init) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
>> [ 3.163462] Exception stack(0xef0c9fb0 to 0xef0c9ff8)
>> [ 3.168519] 9fa0: 00000000 00000000 00000000 00000000
>> [ 3.176706] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
>> [ 3.184893] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
>> [ 3.191695] ---[ end trace a7dc36f7a4ddbdb2 ]---
>> [ 3.197855] ------------[ cut here ]------------
>>
>> Let me know if you can take a look at this.
>
> The warning happens because Cardhu now has CPU OPPs in the device-tree,
> but supported_hw isn't set for the OPPs and thus the count of available
> OPPs is 0.
>
> This is expected to happen because patch "cpufreq: tegra20: Use generic
> cpufreq-dt driver (Tegra30 supported now)" isn't applied yet.
>
> It is possible to factor out the blacklisting of Tegra SoCs in
> cpufreq_dt_platdev_init() into a separate patch and request backporting
> of that change in order to avoid the warning noise for older kernel
> versions + newer device-tree. Please let me know if you think that it's
> worth to do the separation.

Unfortunately, I think we are going to need to drop this patch. Booting
Tegra30-cardhu-a04 with Thierry's for-5.5/arm/dt branch does not even
boot. There is no crash log but it hangs on boot. This patch appears to
be the culprit. What is odd is that Tegra30-cardhu-a04 boots fine with
Thierry's for-next branch which includes this. However, this is causing
lots of bisect problems. Updating the DT shouldn't break the boot.

Jon

--
nvpublic