[PATCH v2 1/1] hwmon (occ): Add temp sensor value check

[Andrew Jeffery]

On Thu, 18 Apr 2019, at 05:07, Guenter Roeck wrote:
> On Wed, Apr 17, 2019 at 01:35:41PM -0500, Eddie James wrote:
> > 
> > On 4/17/19 1:03 PM, Alexander Amelkin wrote:
> > >From: Alexander Soldatov <a.soldatov at yadro.com>
> > >
> > >The occ driver supports two formats for the temp sensor value.
> > >
> > >The OCC firmware for P8 supports only the first format, for which
> > >no range checking or error processing is performed in the driver.
> > >Inspecting the OCC sources for P8 reveals that OCC may send
> > >a special value 0xFFFF to indicate that a sensor read timeout
> > >has occurred, see
> > >
> > >https://github.com/open-power/occ/blob/master_p8/src/occ/cmdh/cmdh_fsp_cmds.c#L395
> > >
> > >That situation wasn't handled in the driver. This patch adds invalid
> > >temp value check for the sensor data format 1 and handles it the same
> > >way as it is done for the format 2, where EREMOTEIO is reported for
> > >this case.
> > 
> > 
> > Thanks Alexander and Guenter.
> > 
> > 
> > Reviewed-by: Eddie James <eajames at linux.ibm.com>
> > 
> 
> Applied.

I've backported and applied this to dev-5.0.

Cheers,

Andrew

> 
> Thanks,
> Guenter
> 
> > 
> > >
> > >Signed-off-by: Alexander Soldatov <a.soldatov at yadro.com>
> > >Signed-off-by: Alexander Amelkin <a.amelkin at yadro.com>
> > >Reviewed-by: Alexander Amelkin <a.amelkin at yadro.com>
> > >Cc: Edward A. James <eajames at us.ibm.com>
> > >Cc: Joel Stanley <joel at jms.id.au>
> > >---
> > >  drivers/hwmon/occ/common.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > >
> > >diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
> > >index 4679acb..825631c 100644
> > >--- a/drivers/hwmon/occ/common.c
> > >+++ b/drivers/hwmon/occ/common.c
> > >@@ -235,6 +235,12 @@ static ssize_t occ_show_temp_1(struct device *dev,
> > >  		val = get_unaligned_be16(&temp->sensor_id);
> > >  		break;
> > >  	case 1:
> > >+		/*
> > >+		 * If a sensor reading has expired and couldn't be refreshed,
> > >+		 * OCC returns 0xFFFF for that sensor.
> > >+		 */
> > >+		if (temp->value == 0xFFFF)
> > >+			return -EREMOTEIO;
> > >  		val = get_unaligned_be16(&temp->value) * 1000;
> > >  		break;
> > >  	default:
> > 
>