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Date:   Mon, 31 Jul 2023 14:24:37 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Abhijit Gangurde <abhijit.gangurde@amd.com>
Cc:     masahiroy@kernel.org, linux-kernel@vger.kernel.org,
        michal.simek@amd.com, git@amd.com, nikhil.agarwal@amd.com,
        Nipun.Gupta@amd.com
Subject: Re: [PATCH v2 1/4] cdx: Introduce lock to protect controller ops and
 controller list
Message-ID: <2023073148-carried-unshaved-77e4@gregkh>
References: <20230731120813.123247-1-abhijit.gangurde@amd.com>
 <20230731120813.123247-2-abhijit.gangurde@amd.com>
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In-Reply-To: <20230731120813.123247-2-abhijit.gangurde@amd.com>
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On Mon, Jul 31, 2023 at 05:38:10PM +0530, Abhijit Gangurde wrote:
> Add a mutex lock to prevent race between controller ops initiated by
> the bus subsystem and the controller registration/unregistration.
> 
> Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
> ---
>  drivers/cdx/cdx.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
> index d2cad4c670a0..66797c8fe400 100644
> --- a/drivers/cdx/cdx.c
> +++ b/drivers/cdx/cdx.c
> @@ -72,6 +72,8 @@
>  
>  /* CDX controllers registered with the CDX bus */
>  static DEFINE_XARRAY_ALLOC(cdx_controllers);
> +/* Lock to protect controller ops and controller list */
> +static DEFINE_MUTEX(cdx_controller_lock);

Wait, why do you have a local list and not just rely on the list the
driver core has for you already?  Isn't this a duplicate list where you
have objects on two different lists with a lifespan controlled only by
one of them?

thanks,

greg k-h