Re: [Letux-kernel] [RFC PATCH 0/3] Enable 1GHz support on omap36xx

[H. Nikolaus Schaller]

Hi Adam,

> Am 11.09.2019 um 02:41 schrieb Adam Ford <aford173@xxxxxxxxx>:
>>>> 

>>>> The error message looks as if we have to enable multi_regulator.

>>> 
>>> That will enable both vdd and vbb regulators from what I can tell in the driver.
>>> 
>>>> And that may need to rename cpu0-supply to vdd-supply (unless the
>>>> names can be configured).
>>> 
>>> That is consistent with what I found.  vdd-supply = <&vcc>; and
>>> vbb-supply = <&abb_mpu_iva>;
>>> I put them both under the cpu node.  Unfortunately, when I did that,
>>> my board crashed.
>>> 
>>> I am thinking it has something to do with the abb_mpu_iva driver
>>> because until this point, we've always operated at 800MHz or lower
>>> which all have the same behavior in abb_mpu_iva.
>>> 
>>> With the patch you posted for the regulator, without the update to
>>> cpufreq,  and with debugging enabled, I received the following in
>>> dmesg:
>>> 
>>> [    1.112518] ti_abb 483072f0.regulator-abb-mpu: Missing
>>> 'efuse-address' IO resource
>>> [    1.112579] ti_abb 483072f0.regulator-abb-mpu: [0]v=1012500 ABB=0
>>> ef=0x0 rbb=0x0 fbb=0x0 vset=0x0
>>> [    1.112609] ti_abb 483072f0.regulator-abb-mpu: [1]v=1200000 ABB=0
>>> ef=0x0 rbb=0x0 fbb=0x0 vset=0x0
>>> [    1.112609] ti_abb 483072f0.regulator-abb-mpu: [2]v=1325000 ABB=0
>>> ef=0x0 rbb=0x0 fbb=0x0 vset=0x0
>>> [    1.112640] ti_abb 483072f0.regulator-abb-mpu: [3]v=1375000 ABB=1
>>> ef=0x0 rbb=0x0 fbb=0x0 vset=0x0
>>> [    1.112731] ti_abb 483072f0.regulator-abb-mpu: ti_abb_init_timings:
>>> Clk_rate=13000000, sr2_cnt=0x00000032
>>> 
>> 
>> Using an unmodified kernel, I changed the device tree to make the abb
>> regulator power the cpu instead of vcc.  After doing so, I was able to
>> read the microvolt value, and it matched the processor's desired OPP
>> voltage, and the debug code showed the abb regulator was attempting to
>> set the various index based on the needed voltage.  I think the abb
>> driver is working correctly.
>> 
>> I think tomorrow, I will re-apply the patches and tweak it again to
>> support both vdd and vbb regulators.  If it crashes again, I'll look
>> more closely at the logs to see if I can determine why.  I think it's
>> pretty close.  I also need to go back and find the SmartReflex stuff
>> as well.
>> 
> Well, I couldn't give it up for the night, so I thought I'd show my data dump
> 
> [    9.807647] ------------[ cut here ]------------
> [    9.812469] WARNING: CPU: 0 PID: 68 at drivers/opp/core.c:630
> dev_pm_opp_set_rate+0x3cc/0x480
> [    9.821044] Modules linked in: sha256_generic sha256_arm cfg80211
> joydev mousedev evdev snd_soc_omap_twl4030(+) leds_gpio led_class
> panel_simple pwm_omap_dmtimer gpio_keys pwm_bl cpufreq_dt omap3_isp v
> ideobuf2_dma_contig videobuf2_memops videobuf2_v4l2 videobuf2_common
> bq27xxx_battery_hdq v4l2_fwnode snd_soc_omap_mcbsp bq27xxx_battery
> snd_soc_ti_sdma omap_wdt videodev mc omap_hdq wlcore_sdio wire cn ph
> y_twl4030_usb hwmon omap2430 musb_hdrc omap_mailbox twl4030_wdt
> watchdog udc_core rtc_twl snd_soc_twl4030 ohci_platform(+)
> snd_soc_core snd_pcm_dmaengine ohci_hcd snd_pcm ehci_omap(+)
> twl4030_pwrbutton sn
> d_timer twl4030_charger snd pwm_twl_led pwm_twl ehci_hcd industrialio
> soundcore twl4030_keypad matrix_keymap usbcore at24 tsc2004
> tsc200x_core usb_common omap_ssi hsi omapdss omapdss_base drm
> drm_panel_or
> ientation_quirks cec
> [    9.894470] CPU: 0 PID: 68 Comm: kworker/0:2 Not tainted
> 5.3.0-rc3-00785-gfdfc7f21c6b7-dirty #5
> [    9.903198] Hardware name: Generic OMAP36xx (Flattened Device Tree)
> [    9.909515] Workqueue: events dbs_work_handler
> [    9.914031] [<c01122d8>] (unwind_backtrace) from [<c010c8b8>]
> (show_stack+0x10/0x14)
> [    9.921813] [<c010c8b8>] (show_stack) from [<c089e858>]
> (dump_stack+0xb4/0xd4)
> [    9.929107] [<c089e858>] (dump_stack) from [<c0139eb0>]
> (__warn.part.3+0xa8/0xd4)
> [    9.936614] [<c0139eb0>] (__warn.part.3) from [<c013a034>]
> (warn_slowpath_null+0x40/0x4c)
> [    9.944854] [<c013a034>] (warn_slowpath_null) from [<c06d666c>]
> (dev_pm_opp_set_rate+0x3cc/0x480)
> [    9.953796] [<c06d666c>] (dev_pm_opp_set_rate) from [<bf1790ac>]
> (set_target+0x30/0x58 [cpufreq_dt])
> [    9.963012] [<bf1790ac>] (set_target [cpufreq_dt]) from
> [<c06db05c>] (__cpufreq_driver_target+0x188/0x514)
> [    9.972717] [<c06db05c>] (__cpufreq_driver_target) from
> [<c06de050>] (od_dbs_update+0x130/0x15c)
> [    9.981567] [<c06de050>] (od_dbs_update) from [<c06deb08>]
> (dbs_work_handler+0x28/0x58)
> [    9.989624] [<c06deb08>] (dbs_work_handler) from [<c0154ab0>]
> (process_one_work+0x20c/0x500)
> [    9.998107] [<c0154ab0>] (process_one_work) from [<c0155e8c>]
> (worker_thread+0x2c/0x5bc)
> [   10.006256] [<c0155e8c>] (worker_thread) from [<c015ab88>]
> (kthread+0x134/0x148)
> [   10.013702] [<c015ab88>] (kthread) from [<c01010e8>]
> (ret_from_fork+0x14/0x2c)
> [   10.020965] Exception stack(0xde63bfb0 to 0xde63bff8)
> [   10.026062] bfa0:                                     00000000
> 00000000 00000000 00000000
> [   10.034271] bfc0: 00000000 00000000 00000000 00000000 00000000
> 00000000 00000000 00000000
> [   10.042510] bfe0: 00000000 00000000 00000000 00000000 00000013 00000000
> [   10.049224] ---[ end trace cf0e15fa4bd57700 ]---
> [   10.053894] cpu cpu0: multiple regulators are not supported
> [   10.059509] cpufreq: __target_index: Failed to change cpu frequency: -22

I have the same:

[    4.701354] cpu cpu0: multiple regulators are not supported
[    4.707794] cpufreq: __target_index: Failed to change cpu frequency: -22

Comes from within dev_pm_opp_set_rate().

It appears that we also have to define opp_table->set_opp to make use
of _set_opp_custom(). And I am not sure which custom-opp-setter we should
use. Maybe ti_opp_supply_set_opp() is ok. Or not.

BR,
Nikolaus