[PATCH] HID: i2c-hid: Send power-on command after reset

[PATCH] HID: i2c-hid: Send power-on command after reset

[Hans de Goede]

Before commit 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power
management"), any i2c-hid touchscreens would typically be runtime-suspended
between the driver loading and Xorg or a Wayland compositor opening it,
causing it to be resumed again. This means that before this change,
we would call i2c_hid_set_power(OFF), i2c_hid_set_power(ON) before the
graphical session would start listening to the touchscreen.

It turns out that at least some SIS touchscreens, such as the one found
on the Asus T100HA, need a power-on command after reset, otherwise they
will not send any events.

Fixes: 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/hid/i2c-hid/i2c-hid-core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index d9c55e30f986..04c088131e04 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -447,8 +447,12 @@ static int i2c_hid_hwreset(struct i2c_client *client)
 	if (ret) {
 		dev_err(&client->dev, "failed to reset device.\n");
 		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
+		goto out_unlock;
 	}
 
+	/* At least some SIS devices need this after reset */
+	ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
+
 out_unlock:
 	mutex_unlock(&ihid->reset_lock);
 	return ret;
-- 
2.23.0

Re: [PATCH] HID: i2c-hid: Send power-on command after reset

[Kai Heng Feng]

Hi Hans,

> On Oct 21, 2019, at 5:47 AM, Hans de Goede <hdegoede@redhat.com> wrote:
> 
> Before commit 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power
> management"), any i2c-hid touchscreens would typically be runtime-suspended
> between the driver loading and Xorg or a Wayland compositor opening it,
> causing it to be resumed again. This means that before this change,
> we would call i2c_hid_set_power(OFF), i2c_hid_set_power(ON) before the
> graphical session would start listening to the touchscreen.
> 
> It turns out that at least some SIS touchscreens, such as the one found
> on the Asus T100HA, need a power-on command after reset, otherwise they
> will not send any events.

As You-Sheng pointed out before, device may need a 60ms delay between ON and RESET command.
Does adding the delay help?

Kai-Heng

> 
> Fixes: 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> drivers/hid/i2c-hid/i2c-hid-core.c | 4 ++++
> 1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
> index d9c55e30f986..04c088131e04 100644
> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
> @@ -447,8 +447,12 @@ static int i2c_hid_hwreset(struct i2c_client *client)
> 	if (ret) {
> 		dev_err(&client->dev, "failed to reset device.\n");
> 		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
> +		goto out_unlock;
> 	}
> 
> +	/* At least some SIS devices need this after reset */
> +	ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
> +
> out_unlock:
> 	mutex_unlock(&ihid->reset_lock);
> 	return ret;
> -- 
> 2.23.0
> 

Re: [PATCH] HID: i2c-hid: Send power-on command after reset

[Hans de Goede]

Hi,

On 21-10-2019 09:17, Kai Heng Feng wrote:
> Hi Hans,
> 
>> On Oct 21, 2019, at 5:47 AM, Hans de Goede <hdegoede@redhat.com> wrote:
>>
>> Before commit 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power
>> management"), any i2c-hid touchscreens would typically be runtime-suspended
>> between the driver loading and Xorg or a Wayland compositor opening it,
>> causing it to be resumed again. This means that before this change,
>> we would call i2c_hid_set_power(OFF), i2c_hid_set_power(ON) before the
>> graphical session would start listening to the touchscreen.
>>
>> It turns out that at least some SIS touchscreens, such as the one found
>> on the Asus T100HA, need a power-on command after reset, otherwise they
>> will not send any events.
> 
> As You-Sheng pointed out before, device may need a 60ms delay between ON and RESET command.
> Does adding the delay help?

I just tried increasing the existing usleep between ON and RESET to:

         usleep_range(60000, 70000);

And this does not help. Note that before we had quirks for devices with a SIS
screen needed, where we avoided the reset on resume and instead did just an
i2c_hid_set_power(client, I2C_HID_PWR_ON) for these.

Which likely was to work around the same problem, these devices simply need a
i2c_hid_set_power(client, I2C_HID_PWR_ON) after rest to function.

Assuming other devices do come up in the "ON" state after reset then this
will be a no-op for them and this should thus not impact their operation.

Also I just noticed that 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
has been added to 5.4-rc# as a fix, so we really need to get this in place
to to not avoid regressing devices with a SIS touchscreen actually quite a
few devices including some quite popular ones uses a SIS touchscreen, here
is the list of devices I know about:

Asus T100HA
Asus T200TA
Peaq 10.1" C1010 2-in-1
Toshiba Click Mini L9W-B

Regards,

Hans



>> Fixes: 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
>> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>> drivers/hid/i2c-hid/i2c-hid-core.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
>> index d9c55e30f986..04c088131e04 100644
>> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
>> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
>> @@ -447,8 +447,12 @@ static int i2c_hid_hwreset(struct i2c_client *client)
>> 	if (ret) {
>> 		dev_err(&client->dev, "failed to reset device.\n");
>> 		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
>> +		goto out_unlock;
>> 	}
>>
>> +	/* At least some SIS devices need this after reset */
>> +	ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
>> +
>> out_unlock:
>> 	mutex_unlock(&ihid->reset_lock);
>> 	return ret;
>> -- 
>> 2.23.0
>>
> 

Re: [PATCH] HID: i2c-hid: Send power-on command after reset

[Kai-Heng Feng]

Hi Hans,

> On Oct 30, 2019, at 23:11, Hans de Goede <hdegoede@redhat.com> wrote:
> 
> Hi,
> 
> On 21-10-2019 09:17, Kai Heng Feng wrote:
>> Hi Hans,
>>> On Oct 21, 2019, at 5:47 AM, Hans de Goede <hdegoede@redhat.com> wrote:
>>> 
>>> Before commit 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power
>>> management"), any i2c-hid touchscreens would typically be runtime-suspended
>>> between the driver loading and Xorg or a Wayland compositor opening it,
>>> causing it to be resumed again. This means that before this change,
>>> we would call i2c_hid_set_power(OFF), i2c_hid_set_power(ON) before the
>>> graphical session would start listening to the touchscreen.
>>> 
>>> It turns out that at least some SIS touchscreens, such as the one found
>>> on the Asus T100HA, need a power-on command after reset, otherwise they
>>> will not send any events.
>> As You-Sheng pointed out before, device may need a 60ms delay between ON and RESET command.
>> Does adding the delay help?
> 
> I just tried increasing the existing usleep between ON and RESET to:
> 
>        usleep_range(60000, 70000);
> 
> And this does not help. Note that before we had quirks for devices with a SIS
> screen needed, where we avoided the reset on resume and instead did just an
> i2c_hid_set_power(client, I2C_HID_PWR_ON) for these.
> 
> Which likely was to work around the same problem, these devices simply need a
> i2c_hid_set_power(client, I2C_HID_PWR_ON) after rest to function.
> 
> Assuming other devices do come up in the "ON" state after reset then this
> will be a no-op for them and this should thus not impact their operation.
> 
> Also I just noticed that 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
> has been added to 5.4-rc# as a fix, so we really need to get this in place
> to to not avoid regressing devices with a SIS touchscreen actually quite a
> few devices including some quite popular ones uses a SIS touchscreen, here
> is the list of devices I know about:

I agree we should use this workaround since increasing delay doesn't work.

Kai-Heng

> 
> Asus T100HA
> Asus T200TA
> Peaq 10.1" C1010 2-in-1
> Toshiba Click Mini L9W-B
> 
> Regards,
> 
> Hans
> 
> 
> 
>>> Fixes: 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
>>> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>> ---
>>> drivers/hid/i2c-hid/i2c-hid-core.c | 4 ++++
>>> 1 file changed, 4 insertions(+)
>>> 
>>> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
>>> index d9c55e30f986..04c088131e04 100644
>>> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
>>> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
>>> @@ -447,8 +447,12 @@ static int i2c_hid_hwreset(struct i2c_client *client)
>>> 	if (ret) {
>>> 		dev_err(&client->dev, "failed to reset device.\n");
>>> 		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
>>> +		goto out_unlock;
>>> 	}
>>> 
>>> +	/* At least some SIS devices need this after reset */
>>> +	ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
>>> +
>>> out_unlock:
>>> 	mutex_unlock(&ihid->reset_lock);
>>> 	return ret;
>>> -- 
>>> 2.23.0

Re: [PATCH] HID: i2c-hid: Send power-on command after reset

[Kai-Heng Feng]

Hi Hans,

> On Oct 31, 2019, at 01:39, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote:
> 
> Hi Hans,
> 
>> On Oct 30, 2019, at 23:11, Hans de Goede <hdegoede@redhat.com> wrote:
>> 
>> Hi,
>> 
>> On 21-10-2019 09:17, Kai Heng Feng wrote:
>>> Hi Hans,
>>>> On Oct 21, 2019, at 5:47 AM, Hans de Goede <hdegoede@redhat.com> wrote:
>>>> 
>>>> Before commit 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power
>>>> management"), any i2c-hid touchscreens would typically be runtime-suspended
>>>> between the driver loading and Xorg or a Wayland compositor opening it,
>>>> causing it to be resumed again. This means that before this change,
>>>> we would call i2c_hid_set_power(OFF), i2c_hid_set_power(ON) before the
>>>> graphical session would start listening to the touchscreen.
>>>> 
>>>> It turns out that at least some SIS touchscreens, such as the one found
>>>> on the Asus T100HA, need a power-on command after reset, otherwise they
>>>> will not send any events.
>>> As You-Sheng pointed out before, device may need a 60ms delay between ON and RESET command.
>>> Does adding the delay help?
>> 
>> I just tried increasing the existing usleep between ON and RESET to:
>> 
>>       usleep_range(60000, 70000);
>> 
>> And this does not help. Note that before we had quirks for devices with a SIS
>> screen needed, where we avoided the reset on resume and instead did just an
>> i2c_hid_set_power(client, I2C_HID_PWR_ON) for these.
>> 
>> Which likely was to work around the same problem, these devices simply need a
>> i2c_hid_set_power(client, I2C_HID_PWR_ON) after rest to function.
>> 
>> Assuming other devices do come up in the "ON" state after reset then this
>> will be a no-op for them and this should thus not impact their operation.
>> 
>> Also I just noticed that 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
>> has been added to 5.4-rc# as a fix, so we really need to get this in place
>> to to not avoid regressing devices with a SIS touchscreen actually quite a
>> few devices including some quite popular ones uses a SIS touchscreen, here
>> is the list of devices I know about:
> 
> I agree we should use this workaround since increasing delay doesn't work.

I just checked the spec again, seems like ON before RESET in probe is unnecessary.
Does removing the ON command in probe help?

> 
> Kai-Heng
> 
>> 
>> Asus T100HA
>> Asus T200TA
>> Peaq 10.1" C1010 2-in-1
>> Toshiba Click Mini L9W-B
>> 
>> Regards,
>> 
>> Hans
>> 
>> 
>> 
>>>> Fixes: 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
>>>> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>> ---
>>>> drivers/hid/i2c-hid/i2c-hid-core.c | 4 ++++
>>>> 1 file changed, 4 insertions(+)
>>>> 
>>>> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
>>>> index d9c55e30f986..04c088131e04 100644
>>>> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
>>>> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
>>>> @@ -447,8 +447,12 @@ static int i2c_hid_hwreset(struct i2c_client *client)
>>>> 	if (ret) {
>>>> 		dev_err(&client->dev, "failed to reset device.\n");
>>>> 		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
>>>> +		goto out_unlock;
>>>> 	}
>>>> 
>>>> +	/* At least some SIS devices need this after reset */
>>>> +	ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
>>>> +
>>>> out_unlock:
>>>> 	mutex_unlock(&ihid->reset_lock);
>>>> 	return ret;
>>>> -- 
>>>> 2.23.0

Re: [PATCH] HID: i2c-hid: Send power-on command after reset

[Hans de Goede]

Hi,

On 31-10-2019 07:23, Kai-Heng Feng wrote:
> Hi Hans,
> 
>> On Oct 31, 2019, at 01:39, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote:
>>
>> Hi Hans,
>>
>>> On Oct 30, 2019, at 23:11, Hans de Goede <hdegoede@redhat.com> wrote:
>>>
>>> Hi,
>>>
>>> On 21-10-2019 09:17, Kai Heng Feng wrote:
>>>> Hi Hans,
>>>>> On Oct 21, 2019, at 5:47 AM, Hans de Goede <hdegoede@redhat.com> wrote:
>>>>>
>>>>> Before commit 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power
>>>>> management"), any i2c-hid touchscreens would typically be runtime-suspended
>>>>> between the driver loading and Xorg or a Wayland compositor opening it,
>>>>> causing it to be resumed again. This means that before this change,
>>>>> we would call i2c_hid_set_power(OFF), i2c_hid_set_power(ON) before the
>>>>> graphical session would start listening to the touchscreen.
>>>>>
>>>>> It turns out that at least some SIS touchscreens, such as the one found
>>>>> on the Asus T100HA, need a power-on command after reset, otherwise they
>>>>> will not send any events.
>>>> As You-Sheng pointed out before, device may need a 60ms delay between ON and RESET command.
>>>> Does adding the delay help?
>>>
>>> I just tried increasing the existing usleep between ON and RESET to:
>>>
>>>        usleep_range(60000, 70000);
>>>
>>> And this does not help. Note that before we had quirks for devices with a SIS
>>> screen needed, where we avoided the reset on resume and instead did just an
>>> i2c_hid_set_power(client, I2C_HID_PWR_ON) for these.
>>>
>>> Which likely was to work around the same problem, these devices simply need a
>>> i2c_hid_set_power(client, I2C_HID_PWR_ON) after rest to function.
>>>
>>> Assuming other devices do come up in the "ON" state after reset then this
>>> will be a no-op for them and this should thus not impact their operation.
>>>
>>> Also I just noticed that 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
>>> has been added to 5.4-rc# as a fix, so we really need to get this in place
>>> to to not avoid regressing devices with a SIS touchscreen actually quite a
>>> few devices including some quite popular ones uses a SIS touchscreen, here
>>> is the list of devices I know about:
>>
>> I agree we should use this workaround since increasing delay doesn't work.
> 
> I just checked the spec again, seems like ON before RESET in probe is unnecessary.
> Does removing the ON command in probe help?

I just tried, removing the ON command done before the RESET does not help.

Regards,

Hans

>>>>> Fixes: 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
>>>>> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
>>>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>>>>> ---
>>>>> drivers/hid/i2c-hid/i2c-hid-core.c | 4 ++++
>>>>> 1 file changed, 4 insertions(+)
>>>>>
>>>>> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
>>>>> index d9c55e30f986..04c088131e04 100644
>>>>> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
>>>>> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
>>>>> @@ -447,8 +447,12 @@ static int i2c_hid_hwreset(struct i2c_client *client)
>>>>> 	if (ret) {
>>>>> 		dev_err(&client->dev, "failed to reset device.\n");
>>>>> 		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
>>>>> +		goto out_unlock;
>>>>> 	}
>>>>>
>>>>> +	/* At least some SIS devices need this after reset */
>>>>> +	ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
>>>>> +
>>>>> out_unlock:
>>>>> 	mutex_unlock(&ihid->reset_lock);
>>>>> 	return ret;
>>>>> -- 
>>>>> 2.23.0
> 

Re: [PATCH] HID: i2c-hid: Send power-on command after reset

[Jiri Kosina]

On Sun, 20 Oct 2019, Hans de Goede wrote:

> Before commit 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power
> management"), any i2c-hid touchscreens would typically be runtime-suspended
> between the driver loading and Xorg or a Wayland compositor opening it,
> causing it to be resumed again. This means that before this change,
> we would call i2c_hid_set_power(OFF), i2c_hid_set_power(ON) before the
> graphical session would start listening to the touchscreen.
> 
> It turns out that at least some SIS touchscreens, such as the one found
> on the Asus T100HA, need a power-on command after reset, otherwise they
> will not send any events.
> 
> Fixes: 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Thanks a lot for debugging this.

I've queued this in for-5.4/upstream-fixes and will make sure it hits 
Linus' tree before 5.4 final.

-- 
Jiri Kosina
SUSE Labs