---
Keijo: could you test this does it fix the issue you reported? This is
practically the same diff I sent earlier what you probably haven't tested yet.
I wanted to send a commitable fix in case it works since I'll be out of
office in a few coming days.
---
 drivers/i2c/i2c-core-base.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 38af18645133..8149c9e32b69 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c

@@ -327,6 +327,8 @@ static int i2c_device_probe(struct device *dev)

               if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
                       dev_dbg(dev, "Using Host Notify IRQ\n");
+                      /* Keep adapter active when Host Notify is required */
+                      pm_runtime_get_sync(&client->adapter->dev);
                       irq = i2c_smbus_host_notify_to_irq(client);
               } else if (dev->of_node) {
                       irq = of_irq_get_byname(dev->of_node, "irq");

@@ -431,6 +433,8 @@ static int i2c_device_remove(struct device *dev)
       device_init_wakeup(&client->dev, false);

       client->irq = client->init_irq;
+      if (client->flags & I2C_CLIENT_HOST_NOTIFY)
+              pm_runtime_put(&client->adapter->dev);

       return status;
 }
--

2.20.1