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Message-Id: <42A39804-8A92-4282-B4AC-BCF5BFC9F0DB@canonical.com>
Date: Wed, 16 Oct 2019 22:17:56 +0800
From: Kai-Heng Feng <kai.heng.feng@...onical.com>
To: Benjamin Tissoires <benjamin.tissoires@...hat.com>
Cc: Hans de Goede <hdegoede@...hat.com>,
Mika Westerberg <mika.westerberg@...ux.intel.com>,
Jiri Kosina <jikos@...nel.org>,
You-Sheng Yang <vicamo.yang@...onical.com>,
"open list:HID CORE LAYER" <linux-input@...r.kernel.org>,
lkml <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] HID: i2c-hid: Remove runtime power management
Hi Benjamin,
> On Oct 11, 2019, at 17:27, Benjamin Tissoires <benjamin.tissoires@...hat.com> wrote:
>
> Hi,
>
> [Adding Mika, who introduced runpm in i2c-hid]
>
> few questions, remarks:
>
> On Tue, Oct 8, 2019 at 10:26 PM Hans de Goede <hdegoede@...hat.com> wrote:
>>
>> 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.
>
> There is also one GPM-like driver that uses libinput (can't remember
> from the top of my head), but you can have the i2c-hid device opened
> on a vt too (with 2 finger gestures for scrolling and what not) :)
Ok, I'll remove it as it's actually a valid use case.
>
> And there is also the use case of a 2-in-1 when the laptop is in
> tablet mode. In some cases, the compositor will close the inputs to
> ignore the touchpad events.
Is it controlled by software? I thought the 2-in-1s handle this by firmware.
>
> Anyway, Mika, is there any drawbacks of not having runpm on i2c-hid
> devices? Maybe at the IRQ level?
>
>>>
>>> - Most importantly, my power meter reports little to none energy saving
>>> when i2c-hid is runtime suspended.
>
> Heh, that was the whole point of HID over I2C: the bus doesn't drain
> power when not in used, so we can have always on devices with little
> to no consumption of energy.
>
> Do you have any numbers, or is it in the noise range?
I think it's even below the noise range.
>
>>>
>>> So let's remove runtime power management since there is no actual
>>> benefit.
>>>
>>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@...onical.com>
>
> Thanks for the patch (one nitpick down below though).
>
>>
>> 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@...hat.com>
>
> Thanks Hans.
>
> You-Sheng, does this solve your issue with your touchpad? Do I have
> your acked-by or tested-by?
This is just a notify to let You-Sheng know that I removed lots of quirk entries. I believe it's a different issue.
>
> Cheers,
> Benjamin
>
>>
>> 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:
>
> shouldn't this label go away?
You are right, I'll send a v2 to address that.
Kai-Heng
>
>>> - 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[] = {
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