linux-kernel - Re: [PATCH] usb: typec: tps6598x: Add support for polling interrupts status

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZCLwx8hU8V+nkzcS@kuha.fi.intel.com>
Date:   Tue, 28 Mar 2023 16:51:03 +0300
From:   Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To:     Roger Quadros <rogerq@...nel.org>
Cc:     gregkh@...uxfoundation.org, vigneshr@...com, srk@...com,
        r-gunasekaran@...com, linux-usb@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Aswath Govindraju <a-govindraju@...com>
Subject: Re: [PATCH] usb: typec: tps6598x: Add support for polling interrupts
 status

On Fri, Mar 24, 2023 at 03:18:53PM +0200, Roger Quadros wrote:
> From: Aswath Govindraju <a-govindraju@...com>
> 
> Some development boards don't have the interrupt line connected.
> 
> In such cases we can resort to polling the interrupt status.
> 
> Signed-off-by: Aswath Govindraju <a-govindraju@...com>
> Signed-off-by: Roger Quadros <rogerq@...nel.org>

Reviewed-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>

> ---
>  drivers/usb/typec/tipd/core.c | 41 ++++++++++++++++++++++++++++++-----
>  1 file changed, 36 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index 485b90c13078..d28ffa10a122 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -16,6 +16,7 @@
>  #include <linux/usb/typec.h>
>  #include <linux/usb/typec_altmode.h>
>  #include <linux/usb/role.h>
> +#include <linux/workqueue.h>
>  
>  #include "tps6598x.h"
>  #include "trace.h"
> @@ -97,6 +98,8 @@ struct tps6598x {
>  
>  	int wakeup;
>  	u16 pwr_status;
> +	struct delayed_work	wq_poll;
> +	irq_handler_t irq_handler;
>  };
>  
>  static enum power_supply_property tps6598x_psy_props[] = {
> @@ -568,6 +571,18 @@ static irqreturn_t tps6598x_interrupt(int irq, void *data)
>  	return IRQ_NONE;
>  }
>  
> +/* Time interval for Polling */
> +#define POLL_INTERVAL	500 /* msecs */
> +static void tps6598x_poll_work(struct work_struct *work)
> +{
> +	struct tps6598x *tps = container_of(to_delayed_work(work),
> +					    struct tps6598x, wq_poll);
> +
> +	tps->irq_handler(0, tps);
> +	queue_delayed_work(system_power_efficient_wq,
> +			   &tps->wq_poll, msecs_to_jiffies(POLL_INTERVAL));
> +}
> +
>  static int tps6598x_check_mode(struct tps6598x *tps)
>  {
>  	char mode[5] = { };
> @@ -746,6 +761,7 @@ static int tps6598x_probe(struct i2c_client *client)
>  			TPS_REG_INT_PLUG_EVENT;
>  	}
>  
> +	tps->irq_handler = irq_handler;
>  	/* Make sure the controller has application firmware running */
>  	ret = tps6598x_check_mode(tps);
>  	if (ret)
> @@ -837,10 +853,18 @@ static int tps6598x_probe(struct i2c_client *client)
>  			dev_err(&client->dev, "failed to register partner\n");
>  	}
>  
> -	ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> -					irq_handler,
> -					IRQF_SHARED | IRQF_ONESHOT,
> -					dev_name(&client->dev), tps);
> +	if (client->irq) {
> +		ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> +						irq_handler,
> +						IRQF_SHARED | IRQF_ONESHOT,
> +						dev_name(&client->dev), tps);
> +	} else {
> +		dev_warn(tps->dev, "Unable to find the interrupt, switching to polling\n");
> +		INIT_DELAYED_WORK(&tps->wq_poll, tps6598x_poll_work);
> +		queue_delayed_work(system_power_efficient_wq, &tps->wq_poll,
> +				   msecs_to_jiffies(POLL_INTERVAL));
> +	}
> +
>  	if (ret)
>  		goto err_disconnect;
>  
> @@ -848,7 +872,7 @@ static int tps6598x_probe(struct i2c_client *client)
>  	fwnode_handle_put(fwnode);
>  
>  	tps->wakeup = device_property_read_bool(tps->dev, "wakeup-source");
> -	if (tps->wakeup) {
> +	if (tps->wakeup && client->irq) {
>  		device_init_wakeup(&client->dev, true);
>  		enable_irq_wake(client->irq);
>  	}
> @@ -887,6 +911,9 @@ static int __maybe_unused tps6598x_suspend(struct device *dev)
>  		enable_irq_wake(client->irq);
>  	}
>  
> +	if (!client->irq)
> +		cancel_delayed_work_sync(&tps->wq_poll);
> +
>  	return 0;
>  }
>  
> @@ -900,6 +927,10 @@ static int __maybe_unused tps6598x_resume(struct device *dev)
>  		enable_irq(client->irq);
>  	}
>  
> +	if (client->irq)
> +		queue_delayed_work(system_power_efficient_wq, &tps->wq_poll,
> +				   msecs_to_jiffies(POLL_INTERVAL));
> +
>  	return 0;
>  }
>  
> -- 
> 2.34.1

-- 
heikki