[PATCH] i3c: master: fix for SETDASA and DAA process

[Parshuram Thombare]

This patch fix following issues.
1. Controller slots blocked for devices with static_addr
   but no init_dyn_addr may limit the number of I3C devices
   on the bus which gets dynamic address in DAA. So
   instead of attaching all the devices with static_addr,
   now we only attach the devices which successfully
   complete SETDASA. Remaining devices are handled in DAA.
2. Since we alreay handled devices with init_dyn_addr, removed
   it's handling from i3c_master_add_i3c_dev_locked().
   Now only case handled is devices already with dyn_addr
   participated in DAA, and again got new dyn_addr with an
   extra slot in the master controller.
3. Removed unnecessary i3c_master_reattach_i3c_dev() from
   i3c_master_add_i3c_dev_locked(), right away after finding
   if duplicate device exists in the I3C list.
   In case of different new and old dyn_addr
   i3c_master_reattach_i3c_dev() will fail which is wrong,
   and in case of same dyn_addr it doesn't add anything new.

Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>
---
 drivers/i3c/master.c | 111 ++++++++++++++++++-------------------------
 1 file changed, 46 insertions(+), 65 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 5f4bd52121fe..f1d929b58549 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1375,6 +1375,11 @@ static int i3c_master_reattach_i3c_dev(struct i3c_dev_desc *dev,
 		i3c_bus_set_addr_slot_status(&master->bus,
 					     dev->info.dyn_addr,
 					     I3C_ADDR_SLOT_I3C_DEV);
+
+		if (old_dyn_addr)
+			i3c_bus_set_addr_slot_status(&master->bus,
+						     old_dyn_addr,
+						     I3C_ADDR_SLOT_FREE);
 	}
 
 	if (master->ops->reattach_i3c_dev) {
@@ -1426,33 +1431,52 @@ static void i3c_master_detach_i2c_dev(struct i2c_dev_desc *dev)
 		master->ops->detach_i2c_dev(dev);
 }
 
-static void i3c_master_pre_assign_dyn_addr(struct i3c_dev_desc *dev)
+static void i3c_master_pre_assign_dyn_addr(struct i3c_master_controller *master,
+					   struct i3c_dev_boardinfo *boardinfo)
 {
-	struct i3c_master_controller *master = i3c_dev_get_master(dev);
+	struct i3c_device_info info = {
+		.static_addr = boardinfo->static_addr,
+	};
+	struct i3c_dev_desc *i3cdev;
 	int ret;
 
-	if (!dev->boardinfo || !dev->boardinfo->init_dyn_addr ||
-	    !dev->boardinfo->static_addr)
+	/*
+	 * We anyway don't attach devices which are not addressable
+	 * (no static_addr and dyn_addr) and devices with static_addr
+	 * but no init_dyn_addr will participate in DAA.
+	 */
+	if (!boardinfo->static_addr || !boardinfo->init_dyn_addr)
+		return;
+
+	i3cdev = i3c_master_alloc_i3c_dev(master, &info);
+	if (IS_ERR(i3cdev))
 		return;
 
-	ret = i3c_master_setdasa_locked(master, dev->info.static_addr,
-					dev->boardinfo->init_dyn_addr);
+	i3cdev->boardinfo = boardinfo;
+
+	ret = i3c_master_attach_i3c_dev(master, i3cdev);
 	if (ret)
 		return;
 
-	dev->info.dyn_addr = dev->boardinfo->init_dyn_addr;
-	ret = i3c_master_reattach_i3c_dev(dev, 0);
+	ret = i3c_master_setdasa_locked(master, i3cdev->info.static_addr,
+					i3cdev->boardinfo->init_dyn_addr);
 	if (ret)
-		goto err_rstdaa;
+		goto err_setdasa;
 
-	ret = i3c_master_retrieve_dev_info(dev);
+	i3cdev->info.dyn_addr = i3cdev->boardinfo->init_dyn_addr;
+	ret = i3c_master_reattach_i3c_dev(i3cdev, 0);
 	if (ret)
 		goto err_rstdaa;
 
-	return;
+	ret = i3c_master_retrieve_dev_info(i3cdev);
+	if (ret)
+		goto err_rstdaa;
 
 err_rstdaa:
-	i3c_master_rstdaa_locked(master, dev->boardinfo->init_dyn_addr);
+	i3c_master_rstdaa_locked(master, i3cdev->boardinfo->init_dyn_addr);
+err_setdasa:
+	i3c_master_detach_i3c_dev(i3cdev);
+	i3c_master_free_i3c_dev(i3cdev);
 }
 
 static void
@@ -1619,8 +1643,8 @@ static void i3c_master_detach_free_devs(struct i3c_master_controller *master)
  * This function is following all initialisation steps described in the I3C
  * specification:
  *
- * 1. Attach I2C and statically defined I3C devs to the master so that the
- *    master can fill its internal device table appropriately
+ * 1. Attach I2C devs to the master so that the master can fill its internal
+ *    device table appropriately
  *
  * 2. Call &i3c_master_controller_ops->bus_init() method to initialize
  *    the master controller. That's usually where the bus mode is selected
@@ -1647,7 +1671,6 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 	enum i3c_addr_slot_status status;
 	struct i2c_dev_boardinfo *i2cboardinfo;
 	struct i3c_dev_boardinfo *i3cboardinfo;
-	struct i3c_dev_desc *i3cdev;
 	struct i2c_dev_desc *i2cdev;
 	int ret;
 
@@ -1679,34 +1702,6 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 			goto err_detach_devs;
 		}
 	}
-	list_for_each_entry(i3cboardinfo, &master->boardinfo.i3c, node) {
-		struct i3c_device_info info = {
-			.static_addr = i3cboardinfo->static_addr,
-		};
-
-		if (i3cboardinfo->init_dyn_addr) {
-			status = i3c_bus_get_addr_slot_status(&master->bus,
-						i3cboardinfo->init_dyn_addr);
-			if (status != I3C_ADDR_SLOT_FREE) {
-				ret = -EBUSY;
-				goto err_detach_devs;
-			}
-		}
-
-		i3cdev = i3c_master_alloc_i3c_dev(master, &info);
-		if (IS_ERR(i3cdev)) {
-			ret = PTR_ERR(i3cdev);
-			goto err_detach_devs;
-		}
-
-		i3cdev->boardinfo = i3cboardinfo;
-
-		ret = i3c_master_attach_i3c_dev(master, i3cdev);
-		if (ret) {
-			i3c_master_free_i3c_dev(i3cdev);
-			goto err_detach_devs;
-		}
-	}
 
 	/*
 	 * Now execute the controller specific ->bus_init() routine, which
@@ -1746,8 +1741,8 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 	 * Pre-assign dynamic address and retrieve device information if
 	 * needed.
 	 */
-	i3c_bus_for_each_i3cdev(&master->bus, i3cdev)
-		i3c_master_pre_assign_dyn_addr(i3cdev);
+	list_for_each_entry(i3cboardinfo, &master->boardinfo.i3c, node)
+		i3c_master_pre_assign_dyn_addr(master, i3cboardinfo);
 
 	ret = i3c_master_do_daa(master);
 	if (ret)
@@ -1811,7 +1806,7 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master,
 {
 	struct i3c_device_info info = { .dyn_addr = addr };
 	struct i3c_dev_desc *newdev, *olddev;
-	u8 old_dyn_addr = addr, expected_dyn_addr;
+	u8 old_dyn_addr = addr;
 	struct i3c_ibi_setup ibireq = { };
 	bool enable_ibi = false;
 	int ret;
@@ -1866,39 +1861,25 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master,
 		i3c_master_free_i3c_dev(olddev);
 	}
 
-	ret = i3c_master_reattach_i3c_dev(newdev, old_dyn_addr);
-	if (ret)
-		goto err_detach_dev;
-
 	/*
 	 * Depending on our previous state, the expected dynamic address might
 	 * differ:
 	 * - if the device already had a dynamic address assigned, let's try to
-	 *   re-apply this one
-	 * - if the device did not have a dynamic address and the firmware
-	 *   requested a specific address, pick this one
+	 *   re-apply this one. Device with dyn_addr participated in DAA ?
 	 * - in any other case, keep the address automatically assigned by the
 	 *   master
 	 */
-	if (old_dyn_addr && old_dyn_addr != newdev->info.dyn_addr)
-		expected_dyn_addr = old_dyn_addr;
-	else if (newdev->boardinfo && newdev->boardinfo->init_dyn_addr)
-		expected_dyn_addr = newdev->boardinfo->init_dyn_addr;
-	else
-		expected_dyn_addr = newdev->info.dyn_addr;
-
-	if (newdev->info.dyn_addr != expected_dyn_addr) {
+	if (old_dyn_addr && old_dyn_addr != newdev->info.dyn_addr) {
 		/*
 		 * Try to apply the expected dynamic address. If it fails, keep
 		 * the address assigned by the master.
 		 */
 		ret = i3c_master_setnewda_locked(master,
 						 newdev->info.dyn_addr,
-						 expected_dyn_addr);
+						 old_dyn_addr);
 		if (!ret) {
-			old_dyn_addr = newdev->info.dyn_addr;
-			newdev->info.dyn_addr = expected_dyn_addr;
-			i3c_master_reattach_i3c_dev(newdev, old_dyn_addr);
+			newdev->info.dyn_addr = old_dyn_addr;
+			i3c_master_reattach_i3c_dev(newdev, addr);
 		} else {
 			dev_err(&master->dev,
 				"Failed to assign reserved/old address to device %d%llx",
-- 
2.17.1