Re: [PATCH] Add an I2C HID quirk for incorrect input length.

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Wed, Nov 27, 2019 at 03:23:29AM +0000, admin@kryma.net wrote:
> From: Pavel Balan <admin@kryma.net>
> 
> Apply it to the Lenovo Y720 gaming laptop I2C peripheral then.
> 
> This fixes dmesg being flooded with errors visible on un-suspend
> in Linux Mint 19 Cinnamon.
> 
> Example of error log:
> 
> <...>
> [    4.326588] i2c_hid i2c-ITE33D1:00: i2c_hid_get_input: incomplete report (2/4)
> [    4.326845] i2c_hid i2c-ITE33D1:00: i2c_hid_get_input: incomplete report (2/4)
> [    4.327095] i2c_hid i2c-ITE33D1:00: i2c_hid_get_input: incomplete report (2/4)
> [    4.327341] i2c_hid i2c-ITE33D1:00: i2c_hid_get_input: incomplete report (2/4)
> [    4.327609] i2c_hid i2c-ITE33D1:00: i2c_hid_get_input: incomplete report (2/4)
> <...>
> 
> Example of fixed log (debug on)
> 
> <...>
> [ 3731.333183] i2c_hid i2c-ITE33D1:00: input: 02 00
> [ 3731.333581] i2c_hid i2c-ITE33D1:00: input: 02 00
> [ 3731.333842] i2c_hid i2c-ITE33D1:00: input: 02 00
> [ 3731.334107] i2c_hid i2c-ITE33D1:00: input: 02 00
> [ 3731.334367] i2c_hid i2c-ITE33D1:00: input: 02 00
> <...>

This should go to Jiri/Benjamin (CCed).

> 
> Signed-off-by: Pavel Balan <admin@kryma.net>
> ---
>  drivers/hid/hid-ids.h              |  1 +
>  drivers/hid/i2c-hid/i2c-hid-core.c | 15 ++++++++++++---
>  2 files changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
> index 76969a22b0f2..ea518daf7435 100644
> --- a/drivers/hid/hid-ids.h
> +++ b/drivers/hid/hid-ids.h
> @@ -628,6 +628,7 @@
>  #define USB_VENDOR_ID_ITE               0x048d
>  #define USB_DEVICE_ID_ITE_LENOVO_YOGA   0x8386
>  #define USB_DEVICE_ID_ITE_LENOVO_YOGA2  0x8350
> +#define I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720	0x837a
>  #define USB_DEVICE_ID_ITE_LENOVO_YOGA900	0x8396
>  #define USB_DEVICE_ID_ITE8595		0x8595
>  
> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
> index 2a7c6e33bb1c..14d964700a7c 100644
> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
> @@ -51,6 +51,7 @@
>  #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)
> +#define I2C_HID_QUIRK_BAD_INPUT_SIZE		BIT(5)
>  
>  /* flags */
>  #define I2C_HID_STARTED		0
> @@ -182,6 +183,8 @@ static const struct i2c_hid_quirks {
>  		I2C_HID_QUIRK_NO_RUNTIME_PM },
>  	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
>  		 I2C_HID_QUIRK_BOGUS_IRQ },
> +	{ USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
> +		I2C_HID_QUIRK_BAD_INPUT_SIZE },
>  	{ 0, 0 }
>  };
>  
> @@ -513,9 +516,15 @@ static void i2c_hid_get_input(struct i2c_hid *ihid)
>  	}
>  
>  	if ((ret_size > size) || (ret_size < 2)) {
> -		dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
> -			__func__, size, ret_size);
> -		return;
> +		if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
> +			ihid->inbuf[0] = size & 0xff;
> +			ihid->inbuf[1] = size >> 8;
> +			ret_size = size;
> +		} else {
> +			dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
> +				__func__, size, ret_size);
> +			return;
> +		}
>  	}
>  
>  	i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
> -- 
> 2.17.1
> 

-- 
Dmitry