hwmon: (lm90) Re-enable interrupts after alert clears

BugLink: https://bugs.launchpad.net/bugs/1959879
[ Upstream commit bc341a1a98827925082e95db174734fc8bd68af6 ]

If alert handling is broken, interrupts are disabled after an alert and
re-enabled after the alert clears. However, if there is an interrupt
handler, this does not apply if alerts were originally disabled and enabled
when the driver was loaded. In that case, interrupts will stay disabled
after an alert was handled though the alert handler even after the alert
condition clears. Address the situation by always re-enabling interrupts
after the alert condition clears if there is an interrupt handler.

Fixes: 2abdc357c55d9 ("hwmon: (lm90) Unmask hardware interrupt")
Cc: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 12a8af36c201b9228ca345690c8bff2ac2ef9b23..09efdc45a6bba98be73eb530ddb25441958eb74e 100644 (file)
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -848,7 +848,7 @@ static int lm90_update_device(struct device *dev)
                 * Re-enable ALERT# output if it was originally enabled and
                 * relevant alarms are all clear
                 */
-               if (!(data->config_orig & 0x80) &&
+               if ((client->irq || !(data->config_orig & 0x80)) &&
                    !(data->alarms & data->alert_alarms)) {
                        if (data->config & 0x80) {
                                dev_dbg(&client->dev, "Re-enabling ALERT#\n");