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author | Hans de Goede <hdegoede@redhat.com> | 2020-11-09 11:57:26 +0100 |
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committer | Thierry Reding <thierry.reding@gmail.com> | 2020-12-17 14:18:49 +0100 |
commit | e3aa45f2f88b6779ab798c63a4deb7ddff949ac7 (patch) | |
tree | 78fa402da641839eb1d8d2d0b6ec64d8fb41baa1 /drivers | |
parent | b9c90f153d836522621b5504087cf83419886e30 (diff) | |
download | linux-e3aa45f2f88b6779ab798c63a4deb7ddff949ac7.tar.gz |
pwm: lpss: Set DPM_FLAG_SMART_SUSPEND on Cherry Trail devices
As the comment above the code setting the DPM_FLAG_NO_DIRECT_COMPLETE flag explains: /* * On Cherry Trail devices the GFX0._PS0 AML checks if the controller * is on and if it is not on it turns it on and restores what it * believes is the correct state to the PWM controller. * Because of this we must disallow direct-complete, which keeps the * controller (runtime)suspended, on resume to avoid 2 issues: * 1. The controller getting turned on without the linux-pm code * knowing about this. On devices where the controller is unused * this causes it to stay on during the next suspend causing high * battery drain (because S0i3 is not reached) * 2. The state restoring code unexpectedly messing with the controller */ The pm-core must not skip resume to avoid the GFX0._PS0 AML code messing with the PWM controller behind our back. But leaving the controller runtime-suspended (skipping runtime-resume + normal-suspend) during suspend is fine. Set the DPM_FLAG_SMART_SUSPEND flag to allow this. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/pwm/pwm-lpss-platform.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c index ac33861edb48..986786be1e49 100644 --- a/drivers/pwm/pwm-lpss-platform.c +++ b/drivers/pwm/pwm-lpss-platform.c @@ -69,9 +69,13 @@ static int pwm_lpss_probe_platform(struct platform_device *pdev) * this causes it to stay on during the next suspend causing high * battery drain (because S0i3 is not reached) * 2. The state restoring code unexpectedly messing with the controller + * + * Leaving the controller runtime-suspended (skipping runtime-resume + + * normal-suspend) during suspend is fine. */ if (info->other_devices_aml_touches_pwm_regs) - dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE); + dev_pm_set_driver_flags(&pdev->dev, DPM_FLAG_NO_DIRECT_COMPLETE| + DPM_FLAG_SMART_SUSPEND); pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); |