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From:   Parshuram Raju Thombare <pthombar@cadence.com>
To:     Parshuram Raju Thombare <pthombar@cadence.com>,
        "bbrezillon@kernel.org" <bbrezillon@kernel.org>,
        "vitor.soares@synopsys.com" <vitor.soares@synopsys.com>
CC:     Przemyslaw Gaj <pgaj@cadence.com>,
        "linux-i3c@lists.infradead.org" <linux-i3c@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Milind Parab <mparab@cadence.com>,
        "praneeth@ti.com" <praneeth@ti.com>
Subject: RE: [PATCH v5] i3c: master: fix for SETDASA and DAA process
Thread-Topic: [PATCH v5] i3c: master: fix for SETDASA and DAA process
Thread-Index: AQHWeqfy8Aj90hsiv0WwsilA8lhg3qlIW8sQ
Date:   Tue, 25 Aug 2020 06:26:01 +0000
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Please ignore this patch.

Regards,
Parshuram Thombare

>-----Original Message-----
>From: Parshuram Thombare <pthombar@cadence.com>
>Sent: Tuesday, August 25, 2020 11:51 AM
>To: bbrezillon@kernel.org; vitor.soares@synopsys.com
>Cc: Przemyslaw Gaj <pgaj@cadence.com>; linux-i3c@lists.infradead.org; linu=
x-
>kernel@vger.kernel.org; Milind Parab <mparab@cadence.com>;
>praneeth@ti.com; Parshuram Raju Thombare <pthombar@cadence.com>
>Subject: [PATCH v5] i3c: master: fix for SETDASA and DAA process
>
>This patch fixes the following issue.
>Controller slots blocked for the devices with only static_addr
>or 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. Similarly, for the devices with only
>init_dyn_addr, init_dyn_addr are reserved, and after DAA
>i3c_master_add_i3c_dev_locked() will try to set the requested
>dynamic address.
>
>Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
>---
>Changes between v4 and v5 are:
>1. Modifications in comments and labels.
>
>Changes between v3 and v4 are:
>1. Code rectoring and removed Fixes tag.
>
>Changes between v2 and v3 are:
>1. Keeping init_dyn_addr reserved.
>2. Code refactoring and changes in comments.
>
>Changes between v1 and v2 are:
>1. Added boardinfo attach fix.
>2. Removed reattach issue related fix.
>3. Reserve init_dyn_addr initially, so that it will not
>   be used in DAA and  attempt can be made to set those
>   firmware requested dynamic address after DAA.
>---
> drivers/i3c/master.c |  128 +++++++++++++++++++++++++++++----------------=
----
> 1 files changed, 76 insertions(+), 52 deletions(-)
>
>diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
>index 3d995f2..ccf9b4e 100644
>--- a/drivers/i3c/master.c
>+++ b/drivers/i3c/master.c
>@@ -1367,7 +1367,9 @@ static int i3c_master_reattach_i3c_dev(struct
>i3c_dev_desc *dev,
> 	enum i3c_addr_slot_status status;
> 	int ret;
>
>-	if (dev->info.dyn_addr !=3D old_dyn_addr) {
>+	if (dev->info.dyn_addr !=3D old_dyn_addr &&
>+	    (!dev->boardinfo ||
>+	     dev->info.dyn_addr !=3D dev->boardinfo->init_dyn_addr)) {
> 		status =3D i3c_bus_get_addr_slot_status(&master->bus,
> 						      dev->info.dyn_addr);
> 		if (status !=3D I3C_ADDR_SLOT_FREE)
>@@ -1426,33 +1428,49 @@ 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 int i3c_master_early_i3c_dev_add(struct i3c_master_controller *mas=
ter,
>+					  struct i3c_dev_boardinfo *boardinfo)
> {
>-	struct i3c_master_controller *master =3D i3c_dev_get_master(dev);
>+	struct i3c_device_info info =3D {
>+		.static_addr =3D boardinfo->static_addr,
>+	};
>+	struct i3c_dev_desc *i3cdev;
> 	int ret;
>
>-	if (!dev->boardinfo || !dev->boardinfo->init_dyn_addr ||
>-	    !dev->boardinfo->static_addr)
>-		return;
>+	i3cdev =3D i3c_master_alloc_i3c_dev(master, &info);
>+	if (IS_ERR(i3cdev))
>+		return -ENOMEM;
>+
>+	i3cdev->boardinfo =3D boardinfo;
>
>-	ret =3D i3c_master_setdasa_locked(master, dev->info.static_addr,
>-					dev->boardinfo->init_dyn_addr);
>+	ret =3D i3c_master_attach_i3c_dev(master, i3cdev);
> 	if (ret)
>-		return;
>+		goto err_free_dev;
>+
>+	ret =3D i3c_master_setdasa_locked(master, i3cdev->info.static_addr,
>+					i3cdev->boardinfo->init_dyn_addr);
>+	if (ret)
>+		goto err_detach_dev;
>
>-	dev->info.dyn_addr =3D dev->boardinfo->init_dyn_addr;
>-	ret =3D i3c_master_reattach_i3c_dev(dev, 0);
>+	i3cdev->info.dyn_addr =3D i3cdev->boardinfo->init_dyn_addr;
>+	ret =3D i3c_master_reattach_i3c_dev(i3cdev, 0);
> 	if (ret)
> 		goto err_rstdaa;
>
>-	ret =3D i3c_master_retrieve_dev_info(dev);
>+	ret =3D i3c_master_retrieve_dev_info(i3cdev);
> 	if (ret)
> 		goto err_rstdaa;
>
>-	return;
>+	return 0;
>
> err_rstdaa:
>-	i3c_master_rstdaa_locked(master, dev->boardinfo->init_dyn_addr);
>+	i3c_master_rstdaa_locked(master, i3cdev->boardinfo->init_dyn_addr);
>+err_detach_dev:
>+	i3c_master_detach_i3c_dev(i3cdev);
>+err_free_dev:
>+	i3c_master_free_i3c_dev(i3cdev);
>+
>+	return ret;
> }
>
> static void
>@@ -1619,8 +1637,8 @@ static void i3c_master_detach_free_devs(struct
>i3c_master_controller *master)
>  * This function is following all initialisation steps described in the I=
3C
>  * specification:
>  *
>- * 1. Attach I2C and statically defined I3C devs to the master so that th=
e
>- *    master can fill its internal device table appropriately
>+ * 1. Attach I2C devs to the master so that the master can fill its inter=
nal
>+ *    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 selecte=
d
>@@ -1632,11 +1650,14 @@ static void i3c_master_detach_free_devs(struct
>i3c_master_controller *master)
>  *
>  * 4. Disable all slave events.
>  *
>- * 5. Pre-assign dynamic addresses requested by the FW with SETDASA for I=
3C
>- *    devices that have a static address
>+ * 5. Reserve address slots for I3C devices with init_dyn_addr. And if de=
vices
>+ *    also have static_addr, try to pre-assign dynamic addresses requeste=
d by
>+ *    the FW with SETDASA and attach corresponding statically defined I3C
>+ *    devices to the master.
>  *
>  * 6. Do a DAA (Dynamic Address Assignment) to assign dynamic addresses t=
o all
>- *    remaining I3C devices
>+ *    remaining I3C devices and attach them to the master if the dynamic =
address
>+ *    assignment succeeds
>  *
>  * Once this is done, all I3C and I2C devices should be usable.
>  *
>@@ -1647,7 +1668,6 @@ 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 +1699,6 @@ 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 =3D {
>-			.static_addr =3D i3cboardinfo->static_addr,
>-		};
>-
>-		if (i3cboardinfo->init_dyn_addr) {
>-			status =3D i3c_bus_get_addr_slot_status(&master->bus,
>-						i3cboardinfo->init_dyn_addr);
>-			if (status !=3D I3C_ADDR_SLOT_FREE) {
>-				ret =3D -EBUSY;
>-				goto err_detach_devs;
>-			}
>-		}
>-
>-		i3cdev =3D i3c_master_alloc_i3c_dev(master, &info);
>-		if (IS_ERR(i3cdev)) {
>-			ret =3D PTR_ERR(i3cdev);
>-			goto err_detach_devs;
>-		}
>-
>-		i3cdev->boardinfo =3D i3cboardinfo;
>-
>-		ret =3D 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
>@@ -1743,11 +1735,43 @@ static int i3c_master_bus_init(struct
>i3c_master_controller *master)
> 		goto err_bus_cleanup;
>
> 	/*
>-	 * Pre-assign dynamic address and retrieve device information if
>-	 * needed.
>+	 * Reserve init_dyn_addr first, and then try to pre-assign dynamic
>+	 * address and retrieve device information if needed.
>+	 * In case pre-assign dynamic address fails, setting dynamic address to
>+	 * the requested init_dyn_addr is retried after DAA is done in
>+	 * i3c_master_add_i3c_dev_locked().
> 	 */
>-	i3c_bus_for_each_i3cdev(&master->bus, i3cdev)
>-		i3c_master_pre_assign_dyn_addr(i3cdev);
>+	list_for_each_entry(i3cboardinfo, &master->boardinfo.i3c, node) {
>+
>+		/*
>+		 * We don't reserve a dynamic address for devices that
>+		 * don't explicitly request one.
>+		 */
>+		if (!i3cboardinfo->init_dyn_addr)
>+			continue;
>+
>+		ret =3D i3c_bus_get_addr_slot_status(&master->bus,
>+						   i3cboardinfo->init_dyn_addr);
>+		if (ret !=3D I3C_ADDR_SLOT_FREE) {
>+			ret =3D -EBUSY;
>+			goto err_rstdaa;
>+		}
>+
>+		i3c_bus_set_addr_slot_status(&master->bus,
>+					     i3cboardinfo->init_dyn_addr,
>+					     I3C_ADDR_SLOT_I3C_DEV);
>+
>+		/*
>+		 * Only try to create/attach devices that have a static
>+		 * address. Other devices will be created/attached when
>+		 * DAA happens, and the requested dynamic address will
>+		 * be set using SETNEWDA once those devices become
>+		 * addressable.
>+		 */
>+
>+		if (i3cboardinfo->static_addr)
>+			i3c_master_early_i3c_dev_add(master, i3cboardinfo);
>+	}
>
> 	ret =3D i3c_master_do_daa(master);
> 	if (ret)
>--
>1.7.1