Re: [PATCH 1/4] i3c: master: detach and free device if pre_assign_dyn_addr() fails

Boris Brezillon
2019-08-29T10:41:24Z

+Przemek

Please try to Cc active I3C contributors so they get a chance to
comment on your patches.

On Thu, 29 Aug 2019 12:19:32 +0200
Vitor Soares <Vitor.Soares@synopsys.com> wrote:

> On pre_assing_dyn_addr() the devices that fail:
> i3c_master_setdasa_locked()
> i3c_master_reattach_i3c_dev()
> i3c_master_retrieve_dev_info()
>
> are kept in memory and master->bus.devs list. This makes the i3c devices
> without a dynamic address are sent on DEFSLVS CCC command. Fix this by
> detaching and freeing the devices that fail on pre_assign_dyn_addr().

I don't think removing those entries is a good strategy, as one might
want to try to use a different dynamic address if the requested one
is not available. Why not simply skipping entries that have ->dyn_addr
set to 0 when preparing a DEFSLVS frame

>
> Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
> ---
> drivers/i3c/master.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 5f4bd52..4d29e1f 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -1438,7 +1438,7 @@ static void i3c_master_pre_assign_dyn_addr(struct i3c_dev_desc *dev)
> ret = i3c_master_setdasa_locked(master, dev->info.static_addr,
> dev->boardinfo->init_dyn_addr);
> if (ret)
> - return;
> + goto err_detach_dev;
>
> dev->info.dyn_addr = dev->boardinfo->init_dyn_addr;
> ret = i3c_master_reattach_i3c_dev(dev, 0);
> @@ -1453,6 +1453,10 @@ static void i3c_master_pre_assign_dyn_addr(struct i3c_dev_desc *dev)
>
> err_rstdaa:
> i3c_master_rstdaa_locked(master, dev->boardinfo->init_dyn_addr);
> +
> +err_detach_dev:
> + i3c_master_detach_i3c_dev(dev);
> + i3c_master_free_i3c_dev(dev);

We certainly shouldn't detach/free the i3c_dev_desc from here. If it
has to be done somewhere (which I'd like to avoid), it should be done
in i3c_master_bus_init() (i3c_master_pre_assign_dyn_addr() should be
converted to return an int in that case).

> }
>
> static void
> @@ -1647,7 +1651,7 @@ 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 i3c_dev_desc *i3cdev, *i3ctmp;
> struct i2c_dev_desc *i2cdev;
> int ret;
>
> @@ -1746,7 +1750,8 @@ 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)
> + list_for_each_entry_safe(i3cdev, i3ctmp, &master->bus.devs.i3c,
> + common.node)
> i3c_master_pre_assign_dyn_addr(i3cdev);
>
> ret = i3c_master_do_daa(master);