Re: [PATCH v9 5/8] soc/tegra: pmc: Implement get_performance_state() callback

[Dmitry Osipenko]

27.08.2021 06:47, Dmitry Osipenko пишет:
> 27.08.2021 06:28, Dmitry Osipenko пишет:
>> 27.08.2021 06:05, Viresh Kumar пишет:
>>> On 27-08-21, 04:34, Dmitry Osipenko wrote:
>>>> +	clk_opp_table = dev_pm_opp_set_clkname(dev, NULL);
>>>> +	if (IS_ERR(clk_opp_table)) {
>>>> +		dev_err(dev, "failed to set OPP clk: %pe\n", clk_opp_table);
>>>> +		ret = PTR_ERR(clk_opp_table);
>>>> +		goto put_hw;
>>>> +	}
>>>
>>> Why do you need to do it ? OPP core already does this automatically.
>>
>> Indeed, thanks.
>>
> 
> Actually, it doesn't work.
> 
> The devm_tegra_core_dev_init_opp_table() needs to set clk to support older device-tree and now OPP table already has clk being set.
> 
> WARNING: CPU: 2 PID: 92 at drivers/opp/core.c:2146 dev_pm_opp_set_clkname+0x97/0xb8
> Modules linked in:
> CPU: 2 PID: 92 Comm: kworker/u8:1 Tainted: G        W         5.14.0-rc7-next-20210826-00181-g6389463cbb0a #9318
> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
> Workqueue: events_unbound deferred_probe_work_func
> [<c010cc91>] (unwind_backtrace) from [<c0108d35>] (show_stack+0x11/0x14)
> [<c0108d35>] (show_stack) from [<c0a6c1bd>] (dump_stack_lvl+0x2b/0x34)
> [<c0a6c1bd>] (dump_stack_lvl) from [<c011fc47>] (__warn+0xbb/0x100)
> [<c011fc47>] (__warn) from [<c0a696e3>] (warn_slowpath_fmt+0x4b/0x80)
> [<c0a696e3>] (warn_slowpath_fmt) from [<c07407b3>] (dev_pm_opp_set_clkname+0x97/0xb8)
> [<c07407b3>] (dev_pm_opp_set_clkname) from [<c07407e3>] (devm_pm_opp_set_clkname+0xf/0x64)
> [<c07407e3>] (devm_pm_opp_set_clkname) from [<c050735b>] (devm_tegra_core_dev_init_opp_table+0x23/0x144)
> [<c050735b>] (devm_tegra_core_dev_init_opp_table) from [<c05aad09>] (gr3d_probe+0x111/0x348)
> [<c05aad09>] (gr3d_probe) from [<c05ba69b>] (platform_probe+0x43/0x84)
> [<c05ba69b>] (platform_probe) from [<c05b8c01>] (really_probe.part.0+0x69/0x200)
> [<c05b8c01>] (really_probe.part.0) from [<c05b8e0b>] (__driver_probe_device+0x73/0xd4)
> [<c05b8e0b>] (__driver_probe_device) from [<c05b8ea1>] (driver_probe_device+0x35/0xd0)
> [<c05b8ea1>] (driver_probe_device) from [<c05b92a9>] (__device_attach_driver+0x75/0x98)
> [<c05b92a9>] (__device_attach_driver) from [<c05b769d>] (bus_for_each_drv+0x51/0x7c)
> [<c05b769d>] (bus_for_each_drv) from [<c05b908f>] (__device_attach+0x8b/0x104)
> [<c05b908f>] (__device_attach) from [<c05b81b3>] (bus_probe_device+0x5b/0x60)
> [<c05b81b3>] (bus_probe_device) from [<c05b5d9f>] (device_add+0x293/0x65c)
> [<c05b5d9f>] (device_add) from [<c0777a4f>] (of_platform_device_create_pdata+0x63/0x88)
> [<c0777a4f>] (of_platform_device_create_pdata) from [<c0777b7d>] (of_platform_bus_create+0xfd/0x26c)
> [<c0777b7d>] (of_platform_bus_create) from [<c0777dc5>] (of_platform_populate+0x45/0x84)
> [<c0777dc5>] (of_platform_populate) from [<c0777e5d>] (devm_of_platform_populate+0x41/0x6c)
> [<c0777e5d>] (devm_of_platform_populate) from [<c05490f9>] (host1x_probe+0x1e9/0x2c8)
> [<c05490f9>] (host1x_probe) from [<c05ba69b>] (platform_probe+0x43/0x84)
> [<c05ba69b>] (platform_probe) from [<c05b8c01>] (really_probe.part.0+0x69/0x200)
> [<c05b8c01>] (really_probe.part.0) from [<c05b8e0b>] (__driver_probe_device+0x73/0xd4)
> [<c05b8e0b>] (__driver_probe_device) from [<c05b8ea1>] (driver_probe_device+0x35/0xd0)
> [<c05b8ea1>] (driver_probe_device) from [<c05b92a9>] (__device_attach_driver+0x75/0x98)
> [<c05b92a9>] (__device_attach_driver) from [<c05b769d>] (bus_for_each_drv+0x51/0x7c)
> [<c05b769d>] (bus_for_each_drv) from [<c05b908f>] (__device_attach+0x8b/0x104)
> [<c05b908f>] (__device_attach) from [<c05b81b3>] (bus_probe_device+0x5b/0x60)
> [<c05b81b3>] (bus_probe_device) from [<c05b8493>] (deferred_probe_work_func+0x57/0x78)
> [<c05b8493>] (deferred_probe_work_func) from [<c0136f73>] (process_one_work+0x147/0x3f8)
> [<c0136f73>] (process_one_work) from [<c0137759>] (worker_thread+0x21d/0x3f4)
> [<c0137759>] (worker_thread) from [<c013c10f>] (kthread+0x123/0x140)
> [<c013c10f>] (kthread) from [<c0100135>] (ret_from_fork+0x11/0x1c)
> ---[ end trace f68728a0d3053b54 ]---
> tegra-gr3d 54180000.gr3d: tegra-soc: failed to set OPP clk: -16
> 

That's because devm_pm_opp_attach_genpd() holds the reference to OPP
table on Tegra30 which uses multiple power domains. See
gr3d_init_power() of the GR3D patch.

It works in case of a single-domain hardware.