linux-kernel - Re: [PATCH] Input: elan_i2c - only increment wakeup count on touch

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Message-ID: <20200630051619.GG248110@dtor-ws>
Date:   Mon, 29 Jun 2020 22:16:19 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Derek Basehore <dbasehore@...omium.org>
Cc:     jiada_wang@...tor.com, jeffrey.l.hugo@...il.com,
        benjamin.tissoires@...hat.com, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Input: elan_i2c - only increment wakeup count on touch

On Mon, Jun 29, 2020 at 05:57:07PM -0700, Derek Basehore wrote:
> This moves the wakeup increment for elan devices to the touch report.
> This prevents the drivers from incorrectly reporting a wakeup when the
> resume callback resets then device, which causes an interrupt to
> occur. This also avoids error messages when these interrupts occur,
> since this behavior is expected.
> 
> Signed-off-by: Derek Basehore <dbasehore@...omium.org>
> ---
>  drivers/input/mouse/elan_i2c_core.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c
> index cdbe6b38c73c1..6ad53a75f9807 100644
> --- a/drivers/input/mouse/elan_i2c_core.c
> +++ b/drivers/input/mouse/elan_i2c_core.c
> @@ -49,6 +49,7 @@
>  
>  #define ETP_MAX_FINGERS		5
>  #define ETP_FINGER_DATA_LEN	5
> +#define ETP_REPORT_LEN_OFFSET	0
>  #define ETP_REPORT_ID		0x5D
>  #define ETP_TP_REPORT_ID	0x5E
>  #define ETP_REPORT_ID_OFFSET	2
> @@ -1018,6 +1019,8 @@ static void elan_report_absolute(struct elan_tp_data *data, u8 *packet)
>  	u8 hover_info = packet[ETP_HOVER_INFO_OFFSET];
>  	bool contact_valid, hover_event;
>  
> +	pm_wakeup_event(&data->client->dev, 0);
> +
>  	hover_event = hover_info & 0x40;
>  	for (i = 0; i < ETP_MAX_FINGERS; i++) {
>  		contact_valid = tp_info & (1U << (3 + i));
> @@ -1041,6 +1044,8 @@ static void elan_report_trackpoint(struct elan_tp_data *data, u8 *report)
>  	u8 *packet = &report[ETP_REPORT_ID_OFFSET + 1];
>  	int x, y;
>  
> +	pm_wakeup_event(&data->client->dev, 0);
> +
>  	if (!data->tp_input) {
>  		dev_warn_once(&data->client->dev,
>  			      "received a trackpoint report while no trackpoint device has been created. Please report upstream.\n");
> @@ -1065,7 +1070,6 @@ static void elan_report_trackpoint(struct elan_tp_data *data, u8 *report)
>  static irqreturn_t elan_isr(int irq, void *dev_id)
>  {
>  	struct elan_tp_data *data = dev_id;
> -	struct device *dev = &data->client->dev;
>  	int error;
>  	u8 report[ETP_MAX_REPORT_LEN];
>  
> @@ -1083,7 +1087,13 @@ static irqreturn_t elan_isr(int irq, void *dev_id)
>  	if (error)
>  		goto out;
>  
> -	pm_wakeup_event(dev, 0);
> +	/*
> +	 * Controllers may send a full length report on power on and reset
> +	 * cases. There are only meaningless bytes in these reports except for
> +	 * report[ETP_REPORT_LEN_OFFSET], which is 0.
> +	 */

Is this true for all versions of firmware? Also, should we pay attention
to the value of this field for various types of reports?

> +	if (!report[ETP_REPORT_LEN_OFFSET])
> +		goto out;
>  
>  	switch (report[ETP_REPORT_ID_OFFSET]) {
>  	case ETP_REPORT_ID:
> @@ -1093,7 +1103,7 @@ static irqreturn_t elan_isr(int irq, void *dev_id)
>  		elan_report_trackpoint(data, report);
>  		break;
>  	default:
> -		dev_err(dev, "invalid report id data (%x)\n",
> +		dev_err(&data->client->dev, "invalid report id data (%x)\n",
>  			report[ETP_REPORT_ID_OFFSET]);
>  	}
>  
> -- 
> 2.27.0.212.ge8ba1cc988-goog
> 

Thanks.

-- 
Dmitry