linux-kernel - Re: [PATCH v3 01/11] i3c: master: Remove i3c_dev_disable_ibi_locked(olddev) on device hotjoin

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Message-ID: <CAPwEoQOXme+GofEhpXaBBmsyGJP-QQtLMJG45PTdNsSqFn391w@mail.gmail.com>
Date: Tue, 20 Aug 2024 09:34:11 +0800
From: Stanley Chu <stanley.chuys@...il.com>
To: Frank Li <Frank.Li@....com>
Cc: Alexandre Belloni <alexandre.belloni@...tlin.com>, 
	Boris Brezillon <boris.brezillon@...labora.com>, Parshuram Thombare <pthombar@...ence.com>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Boris Brezillon <bbrezillon@...nel.org>, 
	Arnd Bergmann <arnd@...db.de>, Miquel Raynal <miquel.raynal@...tlin.com>, 
	Conor Culhane <conor.culhane@...vaco.com>, linux-i3c@...ts.infradead.org, 
	linux-kernel@...r.kernel.org, imx@...ts.linux.dev
Subject: Re: [PATCH v3 01/11] i3c: master: Remove i3c_dev_disable_ibi_locked(olddev)
 on device hotjoin

On Tue, Aug 20, 2024 at 12:02 AM Frank Li <Frank.Li@....com> wrote:
>
> When a new device hotjoins, a new dynamic address is assigned.
> i3c_master_add_i3c_dev_locked() identifies that the device was previously
> attached to the bus and locates the olddev.
>
> i3c_master_add_i3c_dev_locked()
> {
>     ...
>     olddev = i3c_master_search_i3c_dev_duplicate(newdev);
>     ...
>     if (olddev) {
>         ...
>         i3c_dev_disable_ibi_locked(olddev);
>         ^^^^^^
>         The olddev should not receive any commands on the i3c bus as it
>         does not exist and has been assigned a new address. This will
>         result in NACK or timeout. So remove it.
>     }
> }
>
> Fixes: 317bacf960a4 ("i3c: master: add enable(disable) hot join in sys entry")
> Signed-off-by: Frank Li <Frank.Li@....com>
> ---
>  drivers/i3c/master.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 7028f03c2c42e..852b32178b722 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -2039,10 +2039,8 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master,
>                         ibireq.max_payload_len = olddev->ibi->max_payload_len;
>                         ibireq.num_slots = olddev->ibi->num_slots;
>
> -                       if (olddev->ibi->enabled) {
> +                       if (olddev->ibi->enabled)
>                                 enable_ibi = true;
> -                               i3c_dev_disable_ibi_locked(olddev);
> -                       }
>
>                         i3c_dev_free_ibi_locked(olddev);

i3c_dev_free_ibi_locked will still encounter WARN_ON(dev->ibi->enabled).

Thanks,
Stanley

>                 }
>
> --
> 2.34.1
>
>
> --
> linux-i3c mailing list
> linux-i3c@...ts.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-i3c

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