Re: [PATCH] HID: i2c-hid: Remove runtime power management

[Hans de Goede <hdegoede@xxxxxxxxxx>]

Hi,

On 08-10-2019 17:38, Kai-Heng Feng wrote:
> Runtime power management in i2c-hid brings lots of issues, such as:
> - When transitioning from display manager to desktop session, i2c-hid
> was closed and opened, so the device was set to SLEEP and ON in a short
> period. Vendors confirmed that their devices can't handle fast ON/SLEEP
> command because Windows doesn't have this behavior.
>
> - When rebooting, i2c-hid was closed, and the driver core put the device
> back to full power before shutdown. This behavior also triggers a quick
> SLEEP and ON commands that some devices can't handle, renders an
> unusable touchpad after reboot.
>
> - Runtime power management is only useful when i2c-hid isn't opened,
> i.e. a laptop without desktop session, which isn't that common.
>
> - Most importantly, my power meter reports little to none energy saving
> when i2c-hid is runtime suspended.
>
> So let's remove runtime power management since there is no actual
> benefit.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>

Given all the problems we've been seeing related to runtime pm I agree
that this is probably the best approach:

Acked-by: Hans de Goede <hdegoede@xxxxxxxxxx>

Regards,

Hans



> ---
>   drivers/hid/i2c-hid/i2c-hid-core.c | 111 ++---------------------------
>   1 file changed, 4 insertions(+), 107 deletions(-)
>
> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
> index 2a7c6e33bb1c..5ab4982b3a7b 100644
> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
> @@ -26,7 +26,6 @@
>   #include <linux/delay.h>
>   #include <linux/slab.h>
>   #include <linux/pm.h>
> -#include <linux/pm_runtime.h>
>   #include <linux/device.h>
>   #include <linux/wait.h>
>   #include <linux/err.h>
> @@ -48,8 +47,6 @@
>   /* quirks to control the device */
>   #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV	BIT(0)
>   #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET	BIT(1)
> -#define I2C_HID_QUIRK_NO_RUNTIME_PM		BIT(2)
> -#define I2C_HID_QUIRK_DELAY_AFTER_SLEEP		BIT(3)
>   #define I2C_HID_QUIRK_BOGUS_IRQ			BIT(4)
>   
>   /* flags */
> @@ -172,14 +169,7 @@ static const struct i2c_hid_quirks {
>   	{ USB_VENDOR_ID_WEIDA, HID_ANY_ID,
>   		I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
>   	{ I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
> -		I2C_HID_QUIRK_NO_IRQ_AFTER_RESET |
> -		I2C_HID_QUIRK_NO_RUNTIME_PM },
> -	{ I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_4B33,
> -		I2C_HID_QUIRK_DELAY_AFTER_SLEEP },
> -	{ USB_VENDOR_ID_LG, I2C_DEVICE_ID_LG_8001,
> -		I2C_HID_QUIRK_NO_RUNTIME_PM },
> -	{ I2C_VENDOR_ID_GOODIX, I2C_DEVICE_ID_GOODIX_01F0,
> -		I2C_HID_QUIRK_NO_RUNTIME_PM },
> +		I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
>   	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
>   		 I2C_HID_QUIRK_BOGUS_IRQ },
>   	{ 0, 0 }
> @@ -397,7 +387,6 @@ static int i2c_hid_set_power(struct i2c_client *client, int power_state)
>   {
>   	struct i2c_hid *ihid = i2c_get_clientdata(client);
>   	int ret;
> -	unsigned long now, delay;
>   
>   	i2c_hid_dbg(ihid, "%s\n", __func__);
>   
> @@ -415,22 +404,9 @@ static int i2c_hid_set_power(struct i2c_client *client, int power_state)
>   			goto set_pwr_exit;
>   	}
>   
> -	if (ihid->quirks & I2C_HID_QUIRK_DELAY_AFTER_SLEEP &&
> -	    power_state == I2C_HID_PWR_ON) {
> -		now = jiffies;
> -		if (time_after(ihid->sleep_delay, now)) {
> -			delay = jiffies_to_usecs(ihid->sleep_delay - now);
> -			usleep_range(delay, delay + 1);
> -		}
> -	}
> -
>   	ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
>   		0, NULL, 0, NULL, 0);
>   
> -	if (ihid->quirks & I2C_HID_QUIRK_DELAY_AFTER_SLEEP &&
> -	    power_state == I2C_HID_PWR_SLEEP)
> -		ihid->sleep_delay = jiffies + msecs_to_jiffies(20);
> -
>   	if (ret)
>   		dev_err(&client->dev, "failed to change power setting.\n");
>   
> @@ -791,11 +767,6 @@ static int i2c_hid_open(struct hid_device *hid)
>   {
>   	struct i2c_client *client = hid->driver_data;
>   	struct i2c_hid *ihid = i2c_get_clientdata(client);
> -	int ret = 0;
> -
> -	ret = pm_runtime_get_sync(&client->dev);
> -	if (ret < 0)
> -		return ret;
>   
>   	set_bit(I2C_HID_STARTED, &ihid->flags);
>   	return 0;
> @@ -807,27 +778,6 @@ static void i2c_hid_close(struct hid_device *hid)
>   	struct i2c_hid *ihid = i2c_get_clientdata(client);
>   
>   	clear_bit(I2C_HID_STARTED, &ihid->flags);
> -
> -	/* Save some power */
> -	pm_runtime_put(&client->dev);
> -}
> -
> -static int i2c_hid_power(struct hid_device *hid, int lvl)
> -{
> -	struct i2c_client *client = hid->driver_data;
> -	struct i2c_hid *ihid = i2c_get_clientdata(client);
> -
> -	i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
> -
> -	switch (lvl) {
> -	case PM_HINT_FULLON:
> -		pm_runtime_get_sync(&client->dev);
> -		break;
> -	case PM_HINT_NORMAL:
> -		pm_runtime_put(&client->dev);
> -		break;
> -	}
> -	return 0;
>   }
>   
>   struct hid_ll_driver i2c_hid_ll_driver = {
> @@ -836,7 +786,6 @@ struct hid_ll_driver i2c_hid_ll_driver = {
>   	.stop = i2c_hid_stop,
>   	.open = i2c_hid_open,
>   	.close = i2c_hid_close,
> -	.power = i2c_hid_power,
>   	.output_report = i2c_hid_output_report,
>   	.raw_request = i2c_hid_raw_request,
>   };
> @@ -1104,9 +1053,6 @@ static int i2c_hid_probe(struct i2c_client *client,
>   
>   	i2c_hid_acpi_fix_up_power(&client->dev);
>   
> -	pm_runtime_get_noresume(&client->dev);
> -	pm_runtime_set_active(&client->dev);
> -	pm_runtime_enable(&client->dev);
>   	device_enable_async_suspend(&client->dev);
>   
>   	/* Make sure there is something at this address */
> @@ -1154,9 +1100,6 @@ static int i2c_hid_probe(struct i2c_client *client,
>   		goto err_mem_free;
>   	}
>   
> -	if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM))
> -		pm_runtime_put(&client->dev);
> -
>   	return 0;
>   
>   err_mem_free:
> @@ -1166,9 +1109,6 @@ static int i2c_hid_probe(struct i2c_client *client,
>   	free_irq(client->irq, ihid);
>   
>   err_pm:
> -	pm_runtime_put_noidle(&client->dev);
> -	pm_runtime_disable(&client->dev);
> -
>   err_regulator:
>   	regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies),
>   			       ihid->pdata.supplies);
> @@ -1181,12 +1121,6 @@ static int i2c_hid_remove(struct i2c_client *client)
>   	struct i2c_hid *ihid = i2c_get_clientdata(client);
>   	struct hid_device *hid;
>   
> -	if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM))
> -		pm_runtime_get_sync(&client->dev);
> -	pm_runtime_disable(&client->dev);
> -	pm_runtime_set_suspended(&client->dev);
> -	pm_runtime_put_noidle(&client->dev);
> -
>   	hid = ihid->hid;
>   	hid_destroy_device(hid);
>   
> @@ -1219,25 +1153,15 @@ static int i2c_hid_suspend(struct device *dev)
>   	int wake_status;
>   
>   	if (hid->driver && hid->driver->suspend) {
> -		/*
> -		 * Wake up the device so that IO issues in
> -		 * HID driver's suspend code can succeed.
> -		 */
> -		ret = pm_runtime_resume(dev);
> -		if (ret < 0)
> -			return ret;
> -
>   		ret = hid->driver->suspend(hid, PMSG_SUSPEND);
>   		if (ret < 0)
>   			return ret;
>   	}
>   
> -	if (!pm_runtime_suspended(dev)) {
> -		/* Save some power */
> -		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
> +	/* Save some power */
> +	i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
>   
> -		disable_irq(client->irq);
> -	}
> +	disable_irq(client->irq);
>   
>   	if (device_may_wakeup(&client->dev)) {
>   		wake_status = enable_irq_wake(client->irq);
> @@ -1279,11 +1203,6 @@ static int i2c_hid_resume(struct device *dev)
>   				wake_status);
>   	}
>   
> -	/* We'll resume to full power */
> -	pm_runtime_disable(dev);
> -	pm_runtime_set_active(dev);
> -	pm_runtime_enable(dev);
> -
>   	enable_irq(client->irq);
>   
>   	/* Instead of resetting device, simply powers the device on. This
> @@ -1304,30 +1223,8 @@ static int i2c_hid_resume(struct device *dev)
>   }
>   #endif
>   
> -#ifdef CONFIG_PM
> -static int i2c_hid_runtime_suspend(struct device *dev)
> -{
> -	struct i2c_client *client = to_i2c_client(dev);
> -
> -	i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
> -	disable_irq(client->irq);
> -	return 0;
> -}
> -
> -static int i2c_hid_runtime_resume(struct device *dev)
> -{
> -	struct i2c_client *client = to_i2c_client(dev);
> -
> -	enable_irq(client->irq);
> -	i2c_hid_set_power(client, I2C_HID_PWR_ON);
> -	return 0;
> -}
> -#endif
> -
>   static const struct dev_pm_ops i2c_hid_pm = {
>   	SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
> -	SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
> -			   NULL)
>   };
>   
>   static const struct i2c_device_id i2c_hid_id_table[] = {