Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 061cfeb8 authored by Akshay Adiga's avatar Akshay Adiga
Browse files

sx150x-pinctrl: Avoid i2c transfer during kexec 



machine_crash_shutdown() calls irq_bus_sync_unlock() with local irq
disabled. sx150x_irq_bus_sync tries to transfer over i2c bus and hangs
because of disabled irqs.

Add panic handler, so that sx150x_irq_bus_sync_unlock can
return before write to iomap register. Mulitple instances of sx150x
device may be present, hence a global flag to indicate
machine_crash_shutdown() context.

Change-Id: If992f730ba36b81b2a231f3605673e8bae278d16
Signed-off-by: default avatarAkshay Adiga <aadiga@codeaurora.org>
parent 9499b3ff

drivers/pinctrl/pinctrl-sx150x.c

+26 −1
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2019, The Linux Foundation. All rights reserved.

 * Copyright (c) 2019-2020, The Linux Foundation. All rights reserved.

 *

 * Copyright (c) 2016, BayLibre, SAS. All rights reserved.

 * Author: Neil Armstrong <narmstrong@baylibre.com>
@@ -40,6 +40,9 @@ 
#include "pinconf.h"

#include "pinctrl-utils.h"



static bool in_kexec_panic;

static struct notifier_block *panic_block;



/* The chip models of sx150x */

enum {

	SX150X_123 = 0,
@@ -581,6 +584,14 @@ static void sx150x_irq_bus_sync_unlock(struct irq_data *d) 
	struct sx150x_pinctrl *pctl =

			gpiochip_get_data(irq_data_get_irq_chip_data(d));



	/* In crash kexec panic path interrupt is disabled.

	 * Writing to regmap will need interrupt/polling mode,

	 * as it goes though i2c.

	 */

	if (in_kexec_panic) {

		mutex_unlock(&pctl->lock);

		return;

	}

	regmap_write(pctl->regmap, pctl->data->reg_irq_mask, pctl->irq.masked);

	regmap_write(pctl->regmap, pctl->data->reg_sense, pctl->irq.sense);

	mutex_unlock(&pctl->lock);
@@ -1102,6 +1113,14 @@ const struct regmap_config sx150x_regmap_config = { 
	.volatile_reg = sx150x_reg_volatile,

};



static int sx150x_panic_handler(struct notifier_block *this,

				unsigned long event, void *ptr)

{

	if (crash_kexec_post_notifiers)

		in_kexec_panic = 1;

	return NOTIFY_DONE;

}



static int sx150x_probe(struct i2c_client *client,

			const struct i2c_device_id *id)

{
@@ -1301,6 +1320,12 @@ static struct i2c_driver sx150x_driver = { 


static int __init sx150x_init(void)

{

	panic_block = kzalloc(sizeof(*panic_block), GFP_KERNEL);

	if (!panic_block)

		return -ENOMEM;

	panic_block->notifier_call = sx150x_panic_handler;

	atomic_notifier_chain_register(&panic_notifier_list,

				       panic_block);

	return i2c_add_driver(&sx150x_driver);

}

subsys_initcall(sx150x_init);