diff mbox series

HID: i2c-hid: Ignore input report if there's no data present on Elan touchpanels

Message ID 20181214090930.13386-1-kai.heng.feng@canonical.com
State Superseded
Delegated to: Jiri Kosina
Headers show
Series HID: i2c-hid: Ignore input report if there's no data present on Elan touchpanels | expand

Commit Message

Kai-Heng Feng Dec. 14, 2018, 9:09 a.m. UTC
While using Elan touchpads, the message floods:
[  136.138487] i2c_hid i2c-DELL08D6:00: i2c_hid_get_input: incomplete report (14/65535)

Though the message flood is annoying, the device it self works without
any issue. I suspect that the device in question takes too much time to
pull the IRQ back to high after I2C host has done reading its data.

Since the host receives all useful data, let's ignore the input report
when there's no data.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/hid/i2c-hid/i2c-hid-core.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Jiri Kosina Dec. 19, 2018, 1:09 p.m. UTC | #1
On Fri, 14 Dec 2018, Kai-Heng Feng wrote:

> While using Elan touchpads, the message floods:
> [  136.138487] i2c_hid i2c-DELL08D6:00: i2c_hid_get_input: incomplete report (14/65535)
> 
> Though the message flood is annoying, the device it self works without
> any issue. I suspect that the device in question takes too much time to
> pull the IRQ back to high after I2C host has done reading its data.
> 
> Since the host receives all useful data, let's ignore the input report
> when there's no data.

Interesting, never seen such a bug before.

> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
>  drivers/hid/i2c-hid/i2c-hid-core.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
> index 8555ce7e737b..1776afa6d69c 100644
> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
> @@ -50,6 +50,7 @@
>  #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 */
>  #define I2C_HID_STARTED		0
> @@ -179,6 +180,8 @@ static const struct i2c_hid_quirks {
>  		I2C_HID_QUIRK_DELAY_AFTER_SLEEP },
>  	{ USB_VENDOR_ID_LG, I2C_DEVICE_ID_LG_8001,
>  		I2C_HID_QUIRK_NO_RUNTIME_PM },
> +	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
> +		 I2C_HID_QUIRK_BOGUS_IRQ },
>  	{ 0, 0 }
>  };
>  
> @@ -503,6 +506,12 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
>  		return;
>  	}
>  
> +	if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
> +		dev_dbg(&ihid->client->dev,
> +			"%s: IRQ triggered but there's no data\n", __func__);
> +		return;
> +	}

Would it perhaps make sense to make this some sort of printk_once(), so 
that it's immediately apparent from dmesg that the system/device is 
suffering from this particular problem? Might potentially be helpful piece 
of information.

Thanks,
Kai-Heng Feng Dec. 28, 2018, 3:58 p.m. UTC | #2
> On Dec 19, 2018, at 21:09, Jiri Kosina <jikos@kernel.org> wrote:
> 
> On Fri, 14 Dec 2018, Kai-Heng Feng wrote:
> 
>> While using Elan touchpads, the message floods:
>> [  136.138487] i2c_hid i2c-DELL08D6:00: i2c_hid_get_input: incomplete report (14/65535)
>> 
>> Though the message flood is annoying, the device it self works without
>> any issue. I suspect that the device in question takes too much time to
>> pull the IRQ back to high after I2C host has done reading its data.
>> 
>> Since the host receives all useful data, let's ignore the input report
>> when there's no data.
> 
> Interesting, never seen such a bug before.
> 
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
>> ---
>> drivers/hid/i2c-hid/i2c-hid-core.c | 9 +++++++++
>> 1 file changed, 9 insertions(+)
>> 
>> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
>> index 8555ce7e737b..1776afa6d69c 100644
>> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
>> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
>> @@ -50,6 +50,7 @@
>> #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 */
>> #define I2C_HID_STARTED		0
>> @@ -179,6 +180,8 @@ static const struct i2c_hid_quirks {
>> 		I2C_HID_QUIRK_DELAY_AFTER_SLEEP },
>> 	{ USB_VENDOR_ID_LG, I2C_DEVICE_ID_LG_8001,
>> 		I2C_HID_QUIRK_NO_RUNTIME_PM },
>> +	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
>> +		 I2C_HID_QUIRK_BOGUS_IRQ },
>> 	{ 0, 0 }
>> };
>> 
>> @@ -503,6 +506,12 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
>> 		return;
>> 	}
>> 
>> +	if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
>> +		dev_dbg(&ihid->client->dev,
>> +			"%s: IRQ triggered but there's no data\n", __func__);
>> +		return;
>> +	}
> 
> Would it perhaps make sense to make this some sort of printk_once(), so 
> that it's immediately apparent from dmesg that the system/device is 
> suffering from this particular problem? Might potentially be helpful piece 
> of information.

Good advice, I’ll send a v2 patch to address this issue.

Kai-Heng

> 
> Thanks,
> 
> -- 
> Jiri Kosina
> SUSE Labs
>
diff mbox series

Patch

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 8555ce7e737b..1776afa6d69c 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -50,6 +50,7 @@ 
 #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 */
 #define I2C_HID_STARTED		0
@@ -179,6 +180,8 @@  static const struct i2c_hid_quirks {
 		I2C_HID_QUIRK_DELAY_AFTER_SLEEP },
 	{ USB_VENDOR_ID_LG, I2C_DEVICE_ID_LG_8001,
 		I2C_HID_QUIRK_NO_RUNTIME_PM },
+	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
+		 I2C_HID_QUIRK_BOGUS_IRQ },
 	{ 0, 0 }
 };
 
@@ -503,6 +506,12 @@  static void i2c_hid_get_input(struct i2c_hid *ihid)
 		return;
 	}
 
+	if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
+		dev_dbg(&ihid->client->dev,
+			"%s: IRQ triggered but there's no data\n", __func__);
+		return;
+	}
+
 	if ((ret_size > size) || (ret_size < 2)) {
 		dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
 			__func__, size, ret_size);