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

Parshuram Thombare
2020-05-14T16:30:35Z

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@cadence.com>
---
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