Commit 4e5418f7 authored Jun 05, 2021 by Madhava Reddy Siddareddygari Committed by Guenter Roeck Jun 17, 2021

hwmon: (pmbus_core) Check adapter PEC support



Currently, for Packet Error Checking (PEC) only the controller
is checked for support. This causes problems on the cisco-8000
platform where a SMBUS transaction errors are observed. This is
because PEC has to be enabled only if both controller and
adapter support it.

Added code to check PEC capability for adapter and enable it
only if both controller and adapter supports PEC.

Signed-off-by: Madhava Reddy Siddareddygari <msiddare@cisco.com>
[Upstream from SONiC https://github.com/Azure/sonic-linux-kernel/pull/215

]
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/r/20210605052700.541455-1-pmenzel@molgen.mpg.de


[groeck: Dropped unnecessary continuation line]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

parent 6b6af854

drivers/hwmon/pmbus/pmbus_core.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -2216,12 +2216,15 @@ static int pmbus_init_common(struct i2c_client client, struct pmbus_data data,
		data->has_status_word = true;
		}

		/* Enable PEC if the controller supports it */
		/* Enable PEC if the controller and bus supports it */
		if (!(data->flags & PMBUS_NO_CAPABILITY)) {
		ret = i2c_smbus_read_byte_data(client, PMBUS_CAPABILITY);
		if (ret >= 0 && (ret & PB_CAPABILITY_ERROR_CHECK))
		if (ret >= 0 && (ret & PB_CAPABILITY_ERROR_CHECK)) {
		if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_PEC)) {
		client->flags \|= I2C_CLIENT_PEC;
		}
		}
		}

		/*
		* Check if the chip is write protected. If it is, we can not clear