linux-kernel - Re: [PATCH V2] HID: HID-rmi - ignore to rmi_hid_read

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Date:   Wed, 10 Aug 2022 12:11:47 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     margeyang <marge.yang@...aptics.corp-partner.google.com>,
        dmitry.torokhov@...il.com, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org, benjamin.tissoires@...hat.com
Cc:     marge.yang@...synaptics.com, derek.cheng@...synaptics.com,
        vincent.huang@...synaptics.com
Subject: Re: [PATCH V2] HID: HID-rmi - ignore to rmi_hid_read_block after
 system resumes.

Hi,

On 8/9/22 05:09, margeyang wrote:
> From: Marge Yang <marge.yang@...aptics.corp-partner.google.com>
> 
> The interrupt GPIO will be pulled down once
> after RMI driver reads this command(Report ID:0x0A).
> It will cause "Dark resume test fail" for chromebook device.
> Hence, TP driver will ignore rmi_hid_read_block function once
> after system resumes.
> 
> Signed-off-by: Marge Yang<marge.yang@...aptics.corp-partner.google.com>
> ---
>  drivers/hid/hid-rmi.c | 14 ++++++++++++--
>  include/linux/rmi.h   |  2 ++
>  2 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/hid/hid-rmi.c b/drivers/hid/hid-rmi.c
> index 311eee599ce9..b08b74b0c140 100644
> --- a/drivers/hid/hid-rmi.c
> +++ b/drivers/hid/hid-rmi.c
> @@ -203,7 +203,13 @@ static int rmi_hid_read_block(struct rmi_transport_dev *xport, u16 addr,
>  		if (ret < 0)
>  			goto exit;
>  	}
> -
> +	if ((!!xport) && (xport->ignoreonce == 1)) {

The top of this function has:

       struct rmi_data *data = container_of(xport, struct rmi_data, xport);

and data gets dereferenced unconditionally in various places,
so there is no need for the xport check, please change this to just:

	if (xport->ignoreonce == 1) {

Otherwise this looks good to me now.

Regards,

Hans


> +		dev_err(&hdev->dev,
> +			"ignoreonce (%d)\n",
> +			xport->ignoreonce);
> +		xport->ignoreonce = 0;
> +		goto exit;
> +	}
>  	for (retries = 5; retries > 0; retries--) {
>  		data->writeReport[0] = RMI_READ_ADDR_REPORT_ID;
>  		data->writeReport[1] = 0; /* old 1 byte read count */
> @@ -468,8 +474,12 @@ static int rmi_post_resume(struct hid_device *hdev)
>  	ret = hid_hw_open(hdev);
>  	if (ret)
>  		return ret;
> -
> +	// Avoid to read rmi_hid_read_block once after system resumes.
> +	// The interrupt will be pulled down
> +	// after RMI Read command(Report ID:0x0A).
> +	data->xport.ignoreonce = 1;
>  	ret = rmi_reset_attn_mode(hdev);
> +	data->xport.ignoreonce = 0;
>  	if (ret)
>  		goto out;
>  
> diff --git a/include/linux/rmi.h b/include/linux/rmi.h
> index ab7eea01ab42..24f63ad00970 100644
> --- a/include/linux/rmi.h
> +++ b/include/linux/rmi.h
> @@ -270,6 +270,8 @@ struct rmi_transport_dev {
>  	struct rmi_device_platform_data pdata;
>  
>  	struct input_dev *input;
> +
> +	int ignoreonce;
>  };
>  
>  /**