Commit 6b27354c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 

Pull i2c fixes from Wolfram Sang:
 "An I2C core fix to prevent a use-after-free in a rare error path,
  and an I2C ACPI addition to work around broken HW/firmware related
  to touchscreens"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: core: fix use after free in of_i2c_notify
  i2c: acpi: Force bus speed to 400KHz if a Silead touchscreen is present
parents 1d4c79ed a4c2fec1

drivers/i2c/i2c-core-acpi.c

+27 −1
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ struct i2c_acpi_lookup { 
	int index;

	u32 speed;

	u32 min_speed;

	u32 force_speed;

};



/**
@@ -285,6 +286,19 @@ i2c_acpi_match_device(const struct acpi_device_id *matches, 
	return acpi_match_device(matches, &client->dev);

}



static const struct acpi_device_id i2c_acpi_force_400khz_device_ids[] = {

	/*

	 * These Silead touchscreen controllers only work at 400KHz, for

	 * some reason they do not work at 100KHz. On some devices the ACPI

	 * tables list another device at their bus as only being capable

	 * of 100KHz, testing has shown that these other devices work fine

	 * at 400KHz (as can be expected of any recent i2c hw) so we force

	 * the speed of the bus to 400 KHz if a Silead device is present.

	 */

	{ "MSSL1680", 0 },

	{}

};



static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level,

					   void *data, void **return_value)

{
@@ -303,6 +317,9 @@ static acpi_status i2c_acpi_lookup_speed(acpi_handle handle, u32 level, 
	if (lookup->speed <= lookup->min_speed)

		lookup->min_speed = lookup->speed;



	if (acpi_match_device_ids(adev, i2c_acpi_force_400khz_device_ids) == 0)

		lookup->force_speed = 400000;



	return AE_OK;

}
@@ -340,7 +357,16 @@ u32 i2c_acpi_find_bus_speed(struct device *dev) 
		return 0;

	}



	return lookup.min_speed != UINT_MAX ? lookup.min_speed : 0;

	if (lookup.force_speed) {

		if (lookup.force_speed != lookup.min_speed)

			dev_warn(dev, FW_BUG "DSDT uses known not-working I2C bus speed %d, forcing it to %d\n",

				 lookup.min_speed, lookup.force_speed);

		return lookup.force_speed;

	} else if (lookup.min_speed != UINT_MAX) {

		return lookup.min_speed;

	} else {

		return 0;

	}

}

EXPORT_SYMBOL_GPL(i2c_acpi_find_bus_speed);

drivers/i2c/i2c-core-of.c

+2 −2
Original line number Diff line number Diff line
@@ -245,14 +245,14 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action, 
		}



		client = of_i2c_register_device(adap, rd->dn);

		put_device(&adap->dev);



		if (IS_ERR(client)) {

			dev_err(&adap->dev, "failed to create client for '%pOF'\n",

				 rd->dn);

			put_device(&adap->dev);

			of_node_clear_flag(rd->dn, OF_POPULATED);

			return notifier_from_errno(PTR_ERR(client));

		}

		put_device(&adap->dev);

		break;

	case OF_RECONFIG_CHANGE_REMOVE:

		/* already depopulated? */

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