[PATCH linux dev-4.10 v4] hwmon (occ): Add sysfs_notify on error

Eddie James eajames at linux.vnet.ibm.com
Wed Aug 9 13:18:46 AEST 2017



On 08/08/2017 10:13 PM, Joel Stanley wrote:
> From: "Edward A. James" <eajames at us.ibm.com>
>
> For userspace polling, we need to notify sysfs that the state of our
> error entry has changed.
>
> Signed-off-by: Edward A. James <eajames at us.ibm.com>
> Tested-by: Lei YU <mine260309 at gmail.com>
> Signed-off-by: Joel Stanley <joel at jms.id.au>
>
> --
> Changes since v2:
>   * don't return empty sysfs file
> Changes since v3:
>   - remove hard-coded number of errors before reporting
>   - remove use of unusual error code

Looks good. Thanks!

Acked-by: Eddie James <eajames at linux.vnet.ibm.com>

>
> Signed-off-by: Joel Stanley <joel at jms.id.au>
> ---
>   drivers/hwmon/occ/common.c | 42 ++++++++++++++++++++++++++++--------------
>   drivers/hwmon/occ/common.h |  6 +++---
>   drivers/hwmon/occ/p8_i2c.c | 26 ++++++++++++--------------
>   drivers/hwmon/occ/p9_sbe.c | 32 ++++++++++++++------------------
>   4 files changed, 57 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
> index 8b0a00867cfa..a79383435ac9 100644
> --- a/drivers/hwmon/occ/common.c
> +++ b/drivers/hwmon/occ/common.c
> @@ -163,9 +163,21 @@ void occ_parse_poll_response(struct occ *occ)
>   	}
>   }
>
> +void occ_set_error(struct occ *occ, int error)
> +{
> +	occ->error_count++;
> +	occ->error = error;
> +}
> +
> +void occ_reset_error(struct occ *occ)
> +{
> +	occ->error_count = 0;
> +	occ->error = 0;
> +}
> +
>   int occ_poll(struct occ *occ)
>   {
> -	int rc;
> +	int rc, error = occ->error;
>   	struct occ_poll_response_header *header;
>   	u16 checksum = occ->poll_cmd_data + 1;
>   	u8 cmd[8];
> @@ -181,7 +193,7 @@ int occ_poll(struct occ *occ)
>
>   	rc = occ->send_cmd(occ, cmd);
>   	if (rc)
> -		return rc;
> +		goto done;
>
>   	header = (struct occ_poll_response_header *)occ->resp.data;
>
> @@ -197,19 +209,21 @@ int occ_poll(struct occ *occ)
>
>   	if (header->status & OCC_STAT_MASTER) {
>   		if (hweight8(header->occs_present) !=
> -		    atomic_read(&occ_num_occs)) {
> -			occ->error = -EXDEV;
> -			occ->bad_present_count++;
> -		} else
> -			occ->bad_present_count = 0;
> +		    atomic_read(&occ_num_occs))
> +			occ->error = -ENXIO;
>   	}
>
> +done:
> +	/* notify userspace if we change error state and have an error */
> +	if (occ->error != error && occ->error && occ->error_attr_name)
> +		sysfs_notify(&occ->bus_dev->kobj, NULL, occ->error_attr_name);
> +
>   	return rc;
>   }
>
>   int occ_set_user_power_cap(struct occ *occ, u16 user_power_cap)
>   {
> -	int rc;
> +	int rc, error = occ->error;
>   	u8 cmd[8];
>   	u16 checksum = 0x24;
>   	__be16 user_power_cap_be;
> @@ -239,6 +253,10 @@ int occ_set_user_power_cap(struct occ *occ, u16 user_power_cap)
>   	rc = occ->send_cmd(occ, cmd);
>   	mutex_unlock(&occ->lock);
>
> +	/* notify userspace if we change error state and have an error*/
> +	if (occ->error != error && occ->error && occ->error_attr_name)
> +		sysfs_notify(&occ->bus_dev->kobj, NULL, occ->error_attr_name);
> +
>   	return rc;
>   }
>
> @@ -260,14 +278,9 @@ int occ_update_response(struct occ *occ)
>   static ssize_t occ_show_error(struct device *dev,
>   			      struct device_attribute *attr, char *buf)
>   {
> -	int error = 0;
>   	struct occ *occ = dev_get_drvdata(dev);
>
> -	if (occ->error_count > OCC_ERROR_COUNT_THRESHOLD || occ->last_safe ||
> -	    occ->bad_present_count > OCC_ERROR_COUNT_THRESHOLD)
> -		error = occ->error;
> -
> -	return snprintf(buf, PAGE_SIZE - 1, "%d\n", error);
> +	return snprintf(buf, PAGE_SIZE - 1, "%d\n", occ->error);
>   }
>
>   static ssize_t occ_show_status(struct device *dev,
> @@ -1194,6 +1207,7 @@ int occ_create_status_attrs(struct occ *occ)
>   		(struct sensor_device_attribute)SENSOR_ATTR(occ_error, 0444,
>   							    occ_show_error,
>   							    NULL, 0);
> +	occ->error_attr_name = occ->status_attrs[7].dev_attr.attr.name;
>
>   	for (i = 0; i < OCC_NUM_STATUS_ATTRS; ++i) {
>   		rc = device_create_file(dev, &occ->status_attrs[i].dev_attr);
> diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h
> index a5f86c3175f9..ca5969c9df96 100644
> --- a/drivers/hwmon/occ/common.h
> +++ b/drivers/hwmon/occ/common.h
> @@ -13,8 +13,6 @@
>   #include <linux/hwmon-sysfs.h>
>   #include <linux/sysfs.h>
>
> -#define OCC_ERROR_COUNT_THRESHOLD	2
> -
>   #define OCC_UPDATE_FREQUENCY		msecs_to_jiffies(1000)
>   #define OCC_RESP_DATA_BYTES		4089
>
> @@ -103,7 +101,6 @@ struct occ {
>
>   	int error;
>   	unsigned int error_count;
> -	unsigned int bad_present_count;
>   	unsigned long last_safe;
>   	unsigned long last_update;
>   	struct mutex lock;
> @@ -116,6 +113,7 @@ struct occ {
>   	struct attribute_group group;
>   	const struct attribute_group *groups[2];
>   	struct sensor_device_attribute *status_attrs;
> +	const char *error_attr_name;
>
>   	u8 poll_cmd_data;
>   	int (*send_cmd)(struct occ *occ, u8 *cmd);
> @@ -143,6 +141,8 @@ struct occ {
>   extern atomic_t occ_num_occs;
>
>   void occ_parse_poll_response(struct occ *occ);
> +void occ_reset_error(struct occ *occ);
> +void occ_set_error(struct occ *occ, int error);
>   int occ_poll(struct occ *occ);
>   int occ_set_user_power_cap(struct occ *occ, u16 user_power_cap);
>   int occ_update_response(struct occ *occ);
> diff --git a/drivers/hwmon/occ/p8_i2c.c b/drivers/hwmon/occ/p8_i2c.c
> index 29233b473746..05af16b376bb 100644
> --- a/drivers/hwmon/occ/p8_i2c.c
> +++ b/drivers/hwmon/occ/p8_i2c.c
> @@ -98,7 +98,7 @@ static int p8_i2c_occ_putscom_be(struct i2c_client *client, u32 address,
>
>   static int p8_i2c_occ_send_cmd(struct occ *occ, u8 *cmd)
>   {
> -	int i, rc;
> +	int i, rc, error;
>   	unsigned long start;
>   	u16 data_length;
>   	struct p8_i2c_occ *p8_i2c_occ = to_p8_i2c_occ(occ);
> @@ -161,22 +161,18 @@ static int p8_i2c_occ_send_cmd(struct occ *occ, u8 *cmd)
>   		rc = -EFAULT;
>   	}
>
> -	occ->error = resp->return_status;
> -
>   	if (rc < 0) {
> -		occ->error_count++;
> -		dev_warn(&client->dev, "occ bad response:%d\n",
> -			 resp->return_status);
> -		return rc;
> +		error = resp->return_status;
> +		dev_warn(&client->dev, "occ bad response:%d\n", error);
> +		goto done;
>   	}
>
>   	data_length = get_unaligned_be16(&resp->data_length_be);
>   	if (data_length > OCC_RESP_DATA_BYTES) {
> -		occ->error_count++;
> -		occ->error = -EDOM;
> +		rc = -EIO;
>   		dev_warn(&client->dev, "occ bad data length:%d\n",
>   			 data_length);
> -		return occ->error;
> +		goto assign;
>   	}
>
>   	for (i = 8; i < data_length + 7; i += 8) {
> @@ -185,13 +181,15 @@ static int p8_i2c_occ_send_cmd(struct occ *occ, u8 *cmd)
>   			goto err;
>   	}
>
> -	occ->error_count = 0;
> -	return data_length + 7;
> +	occ_reset_error(occ);
> +	return 0;
>
>   err:
> -	occ->error_count++;
> -	occ->error = rc;
>   	dev_err(&client->dev, "i2c scom op failed rc:%d\n", rc);
> +assign:
> +	error = rc;
> +done:
> +	occ_set_error(occ, error);
>   	return rc;
>   }
>
> diff --git a/drivers/hwmon/occ/p9_sbe.c b/drivers/hwmon/occ/p9_sbe.c
> index c85f1339ec33..2d50a94150b1 100644
> --- a/drivers/hwmon/occ/p9_sbe.c
> +++ b/drivers/hwmon/occ/p9_sbe.c
> @@ -25,7 +25,7 @@ struct p9_sbe_occ {
>
>   static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd)
>   {
> -	int rc;
> +	int rc, error;
>   	unsigned long start;
>   	struct occ_client *client;
>   	struct occ_response *resp = &occ->resp;
> @@ -35,9 +35,10 @@ static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd)
>
>   retry:
>   	client = occ_drv_open(p9_sbe_occ->sbe, 0);
> -	if (!client)
> -		/* don't increment occ error counter */
> -		return -ENODEV;
> +	if (!client) {
> +		rc = -ENODEV;
> +		goto assign;
> +	}
>
>   	rc = occ_drv_write(client, (const char *)&cmd[1], 7);
>   	if (rc < 0)
> @@ -62,7 +63,8 @@ static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd)
>   		}
>   		break;
>   	case RESP_RETURN_SUCCESS:
> -		rc = 0;
> +		occ_reset_error(occ);
> +		return 0;
>   		break;
>   	case RESP_RETURN_CMD_INVAL:
>   	case RESP_RETURN_CMD_LEN:
> @@ -77,23 +79,17 @@ static int p9_sbe_occ_send_cmd(struct occ *occ, u8 *cmd)
>   		rc = -EFAULT;
>   	}
>
> -	occ->error = resp->return_status;
> -
> -	if (rc < 0) {
> -		occ->error_count++;
> -		dev_warn(occ->bus_dev, "occ bad response:%d\n",
> -			 resp->return_status);
> -		return rc;
> -	}
> -
> -	occ->error_count = 0;
> -	return 0;
> +	error = resp->return_status;
> +	dev_warn(occ->bus_dev, "occ bad response:%d\n", error);
> +	goto done;
>
>   err:
> -	occ->error_count++;
> -	occ->error = rc;
>   	occ_drv_release(client);
>   	dev_err(occ->bus_dev, "occ bus op failed rc:%d\n", rc);
> +assign:
> +	error = rc;
> +done:
> +	occ_set_error(occ, error);
>   	return rc;
>   }
>



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