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Commit 42ab31e8 authored by Anirudh Ghayal's avatar Anirudh Ghayal
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power: smb135x-charger: Perform I2C reads only after device resumes 



The I2C bus driver while suspended rejects all the I2C transactions.
In a scenario where the wakeup is from an SMB irq, the smb driver
fails to perform i2c reads from its stat interrupt handler which
is invoked while i2c bus is suspended. The SMB chip continuously
fires IRQs until the irq status registers are read leading to
interrupt storm.

To avoid this storm of interrupts, wait in the interrupt handler until
i2c bus resumes. The resume_noirq and resume callback are fair indications
of i2c bus resume completion. Use them in a flag to wait in the interrupt
handler.

Change-Id: I6bbc71a6d4a611556b8365f2b9cce077b8bde911
Signed-off-by: default avatarAnirudh Ghayal <aghayal@codeaurora.org>
parent 8e50e2a6

drivers/power/smb135x-charger.c

+25 −0
Original line number Original line Diff line number Diff line
@@ -256,6 +256,8 @@ struct smb135x_chg { 
	bool				batt_warm;

	bool				batt_warm;

	bool				batt_cool;

	bool				batt_cool;





	struct completion		resumed;

	bool				resume_completed;

	bool				usb_suspended;

	bool				usb_suspended;

	bool				dc_suspended;

	bool				dc_suspended;
@@ -1447,6 +1449,12 @@ static irqreturn_t smb135x_chg_stat_handler(int irq, void *dev_id) 
	int rc;

	int rc;

	int handler_count = 0;

	int handler_count = 0;





	init_completion(&chip->resumed);

	if (!chip->resume_completed) {

		dev_dbg(chip->dev, "IRQ triggered before device-resume\n");

		wait_for_completion_interruptible(&chip->resumed);

	}



	for (i = 0; i < ARRAY_SIZE(handlers); i++) {

	for (i = 0; i < ARRAY_SIZE(handlers); i++) {

		rc = smb135x_read(chip, handlers[i].stat_reg,

		rc = smb135x_read(chip, handlers[i].stat_reg,

						&handlers[i].val);

						&handlers[i].val);
@@ -2266,6 +2274,9 @@ static int smb135x_charger_probe(struct i2c_client *client, 
		}

		}

	}

	}





	chip->resume_completed = true;

	init_completion(&chip->resumed);



	/* STAT irq configuration */

	/* STAT irq configuration */

	if (client->irq) {

	if (client->irq) {

		rc = devm_request_threaded_irq(&client->dev, client->irq, NULL,

		rc = devm_request_threaded_irq(&client->dev, client->irq, NULL,
@@ -2442,6 +2453,16 @@ static int smb135x_suspend(struct device *dev) 
	return 0;

	return 0;

}

}





static int smb135x_resume_noirq(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct smb135x_chg *chip = i2c_get_clientdata(client);



	chip->resume_completed = false;



	return 0;

}



static int smb135x_resume(struct device *dev)

static int smb135x_resume(struct device *dev)

{

{

	struct i2c_client *client = to_i2c_client(dev);

	struct i2c_client *client = to_i2c_client(dev);
@@ -2457,10 +2478,14 @@ static int smb135x_resume(struct device *dev) 
				"Couldn't restore irq cfg regs rc=%d\n", rc);

				"Couldn't restore irq cfg regs rc=%d\n", rc);

	}

	}





	chip->resume_completed = true;

	complete(&chip->resumed);



	return 0;

	return 0;

}

}





static const struct dev_pm_ops smb135x_pm_ops = {

static const struct dev_pm_ops smb135x_pm_ops = {

	.resume_noirq	= smb135x_resume_noirq,

	.resume		= smb135x_resume,

	.resume		= smb135x_resume,

	.suspend	= smb135x_suspend,

	.suspend	= smb135x_suspend,

};

};