Merge tag 'i2c-for-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c fixes from Wolfram Sang:

 - Two fixes for SMBusAlert handling in the I2C core: one to avoid an
   endless loop when scanning for handlers and one to make sure handlers
   are always called even if HW has broken behaviour

 - I2C header build fix for when ACPI is enabled but I2C isn't

 - The testunit gets a rename in the code to match the documentation

 - Two fixes for the Qualcomm GENI I2C controller are cleaning up the
   error exit patch in the runtime_resume() function. The first is
   disabling the clock, the second disables the icc on the way out

* tag 'i2c-for-6.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: testunit: match HostNotify test name with docs
  i2c: qcom-geni: Add missing geni_icc_disable in geni_i2c_runtime_resume
  i2c: qcom-geni: Add missing clk_disable_unprepare in geni_i2c_runtime_resume
  i2c: Fix conditional for substituting empty ACPI functions
  i2c: smbus: Send alert notifications to all devices if source not found
  i2c: smbus: Improve handling of stuck alerts

Author: torvalds

drivers/i2c/busses/i2c-qcom-geni.c

@@ -990,8 +990,11 @@ static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
 		return ret;
 
 	ret = geni_se_resources_on(&gi2c->se);
-	if (ret)
+	if (ret) {
+		clk_disable_unprepare(gi2c->core_clk);
+		geni_icc_disable(&gi2c->se);
 		return ret;
+	}
 
 	enable_irq(gi2c->irq);
 	gi2c->suspended = 0;

drivers/i2c/i2c-slave-testunit.c

@@ -18,7 +18,7 @@
 
 enum testunit_cmds {
 	TU_CMD_READ_BYTES = 1,	/* save 0 for ABORT, RESET or similar */
-	TU_CMD_HOST_NOTIFY,
+	TU_CMD_SMBUS_HOST_NOTIFY,
 	TU_CMD_SMBUS_BLOCK_PROC_CALL,
 	TU_NUM_CMDS
 };
@@ -60,7 +60,7 @@ static void i2c_slave_testunit_work(struct work_struct *work)
 		msg.len = tu->regs[TU_REG_DATAH];
 		break;
 
-	case TU_CMD_HOST_NOTIFY:
+	case TU_CMD_SMBUS_HOST_NOTIFY:
 		msg.addr = 0x08;
 		msg.flags = 0;
 		msg.len = 3;

drivers/i2c/i2c-smbus.c

@@ -34,6 +34,7 @@ static int smbus_do_alert(struct device *dev, void *addrp)
 	struct i2c_client *client = i2c_verify_client(dev);
 	struct alert_data *data = addrp;
 	struct i2c_driver *driver;
+	int ret;
 
 	if (!client || client->addr != data->addr)
 		return 0;
@@ -47,16 +48,47 @@ static int smbus_do_alert(struct device *dev, void *addrp)
 	device_lock(dev);
 	if (client->dev.driver) {
 		driver = to_i2c_driver(client->dev.driver);
-		if (driver->alert)
+		if (driver->alert) {
+			/* Stop iterating after we find the device */
 			driver->alert(client, data->type, data->data);
-		else
+			ret = -EBUSY;
+		} else {
 			dev_warn(&client->dev, "no driver alert()!\n");
-	} else
+			ret = -EOPNOTSUPP;
+		}
+	} else {
 		dev_dbg(&client->dev, "alert with no driver\n");
+		ret = -ENODEV;
+	}
+	device_unlock(dev);
+
+	return ret;
+}
+
+/* Same as above, but call back all drivers with alert handler */
+
+static int smbus_do_alert_force(struct device *dev, void *addrp)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	struct alert_data *data = addrp;
+	struct i2c_driver *driver;
+
+	if (!client || (client->flags & I2C_CLIENT_TEN))
+		return 0;
+
+	/*
+	 * Drivers should either disable alerts, or provide at least
+	 * a minimal handler. Lock so the driver won't change.
+	 */
+	device_lock(dev);
+	if (client->dev.driver) {
+		driver = to_i2c_driver(client->dev.driver);
+		if (driver->alert)
+			driver->alert(client, data->type, data->data);
+	}
 	device_unlock(dev);
 
-	/* Stop iterating after we find the device */
-	return -EBUSY;
+	return 0;
 }
 
 /*
@@ -67,6 +99,7 @@ static irqreturn_t smbus_alert(int irq, void *d)
 {
 	struct i2c_smbus_alert *alert = d;
 	struct i2c_client *ara;
+	unsigned short prev_addr = I2C_CLIENT_END; /* Not a valid address */
 
 	ara = alert->ara;
 
@@ -94,8 +127,25 @@ static irqreturn_t smbus_alert(int irq, void *d)
 			data.addr, data.data);
 
 		/* Notify driver for the device which issued the alert */
-		device_for_each_child(&ara->adapter->dev, &data,
-				      smbus_do_alert);
+		status = device_for_each_child(&ara->adapter->dev, &data,
+					       smbus_do_alert);
+		/*
+		 * If we read the same address more than once, and the alert
+		 * was not handled by a driver, it won't do any good to repeat
+		 * the loop because it will never terminate. Try again, this
+		 * time calling the alert handlers of all devices connected to
+		 * the bus, and abort the loop afterwards. If this helps, we
+		 * are all set. If it doesn't, there is nothing else we can do,
+		 * so we might as well abort the loop.
+		 * Note: This assumes that a driver with alert handler handles
+		 * the alert properly and clears it if necessary.
+		 */
+		if (data.addr == prev_addr && status != -EBUSY) {
+			device_for_each_child(&ara->adapter->dev, &data,
+					      smbus_do_alert_force);
+			break;
+		}
+		prev_addr = data.addr;
 	}
 
 	return IRQ_HANDLED;

include/linux/i2c.h

@@ -1066,7 +1066,7 @@ static inline int of_i2c_get_board_info(struct device *dev,
 struct acpi_resource;
 struct acpi_resource_i2c_serialbus;
 
-#if IS_ENABLED(CONFIG_ACPI)
+#if IS_ENABLED(CONFIG_ACPI) && IS_ENABLED(CONFIG_I2C)
 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares,
 			       struct acpi_resource_i2c_serialbus **i2c);
 int i2c_acpi_client_count(struct acpi_device *adev);