linux-kernel - Re: [PATCH v9 52/55] input: touchscreen: atmel_mxt_ts: Added sysfs entry for touchscreen status

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Date:   Fri, 27 Mar 2020 21:49:14 +0900
From:   "Wang, Jiada" <jiada_wang@...tor.com>
To:     Dmitry Osipenko <digetx@...il.com>, <nick@...anahar.org>,
        <dmitry.torokhov@...il.com>, <jikos@...nel.org>,
        <benjamin.tissoires@...hat.com>, <bsz@...ihalf.com>,
        <rydberg@...math.org>
CC:     <linux-input@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <erosca@...adit-jv.com>, <Andrew_Gabbasov@...tor.com>
Subject: Re: [PATCH v9 52/55] input: touchscreen: atmel_mxt_ts: Added sysfs
 entry for touchscreen status

Hi Dmitry

On 2020/03/26 4:35, Dmitry Osipenko wrote:
> 25.03.2020 16:33, Jiada Wang пишет:
>> From: Naveen Chakka <Naveen.Chakka@...bosch.com>
>>
>> To know the current communication status of the touch controller during
>> runtime, sysfs interface is added
>>
>> sysfs interface: /sys/class/i2c-dev/i2c-*/device/*/touch_dev_stat
>> Executing the above sysfs interface provides two output values
>>
>> 1)Status of the touch device
>> 	value 0 represents device is inactive
>> 	value 1 represents device is active
>> 2)Error counter
>> 	value represents the number of times device in inactive since last read
> 
> ...
>>   /* Each client has this additional data */
>>   struct mxt_data {
>>   	struct i2c_client *client;
>> @@ -372,6 +380,9 @@ struct mxt_data {
>>   	const char *pcfg_name;
>>   	const char *input_name;
>>   	struct mxt_flash *flash;
> 
>> +	struct work_struct watchdog_work;
>> +	struct timer_list watchdog_timer;
> 
> This should be replaced with a delayed_work.

will replace with delayer_work
> 
>> +	struct mxt_statusinfo mxt_status;
>>   
>>   	/* Cached parameters from object table */
>>   	u16 T5_address;
> 
> ...
>> +static void mxt_watchdog_work(struct work_struct *work)
>> +{
>> +	struct mxt_data *data =
>> +		container_of(work, struct mxt_data, watchdog_work);
>> +	u16 info_buf;
>> +	int ret = 0;
>> +	u8 size = 2;
> 
>> +	if (data->suspended || data->in_bootloader)
>> +		return;
>> +
>> +	ret = __mxt_read_reg(data->client, 0, size, &info_buf);
> 
> Looks like this need to be protected with a lock to not race with the
> suspending / bootloader states.
> 
right, I will add lock in next version

>> +	if (ret) {
>> +		data->mxt_status.error_count++;
>> +		data->mxt_status.dev_status = false;
>> +	} else {
>> +		data->mxt_status.dev_status = true;
>> +	}
>> +}
> 
> ...> @@ -4329,6 +4414,13 @@ static int mxt_probe(struct i2c_client
> *client, const struct i2c_device_id *id)
>>   		msleep(MXT_RESET_TIME);
>>   	}
>>   
>> +	INIT_WORK(&data->watchdog_work, mxt_watchdog_work);
>> +
>> +	/* setup watchdog timer */
>> +	timer_setup(&data->watchdog_timer, mxt_watchdog_timer, 0);
>> +
>> +	mxt_start_wd_timer(data);
> 
> I'd expect it to be optional and opt-in by either using #ifdef
> TOUCHSCREEN_ATMEL_MXT_DEBUG or having a new debugfs option to explicitly
> enable the "watchdog".
> 
Thanks for your suggestion, I will use module_param to enable/disable
watchdog

Thanks,
Jiada