Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 8 Sep 2022 13:54:29 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     "Isaac J. Manjarres" <isaacmanjarres@google.com>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Tomeu Vizoso <tomeu.vizoso@collabora.com>,
        Russell King <rmk+kernel@arm.linux.org.uk>,
        Ulf Hansson <ulf.hansson@linaro.org>, stable@vger.kernel.org,
        Saravana Kannan <saravanak@google.com>,
        Guenter Roeck <linux@roeck-us.net>,
        Linus Walleij <linus.walleij@linaro.org>,
        kernel-team@android.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH stable-4.19/4.14/4.9] driver core: Don't probe devices
 after bus_type.match() probe deferral
Message-ID: <YxnX9TsxuSi9L9GD@kroah.com>
References: <20220906172933.410698-1-isaacmanjarres@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220906172933.410698-1-isaacmanjarres@google.com>
Precedence: bulk

On Tue, Sep 06, 2022 at 10:29:33AM -0700, Isaac J. Manjarres wrote:
> commit 25e9fbf0fd38868a429feabc38abebfc6dbf6542 upstream.
> 
> Both __device_attach_driver() and __driver_attach() check the return
> code of the bus_type.match() function to see if the device needs to be
> added to the deferred probe list. After adding the device to the list,
> the logic attempts to bind the device to the driver anyway, as if the
> device had matched with the driver, which is not correct.
> 
> If __device_attach_driver() detects that the device in question is not
> ready to match with a driver on the bus, then it doesn't make sense for
> the device to attempt to bind with the current driver or continue
> attempting to match with any of the other drivers on the bus. So, update
> the logic in __device_attach_driver() to reflect this.
> 
> If __driver_attach() detects that a driver tried to match with a device
> that is not ready to match yet, then the driver should not attempt to bind
> with the device. However, the driver can still attempt to match and bind
> with other devices on the bus, as drivers can be bound to multiple
> devices. So, update the logic in __driver_attach() to reflect this.
> 
> Fixes: 656b8035b0ee ("ARM: 8524/1: driver cohandle -EPROBE_DEFER from bus_type.match()")
> Cc: stable@vger.kernel.org
> Cc: Saravana Kannan <saravanak@google.com>
> Reported-by: Guenter Roeck <linux@roeck-us.net>
> Tested-by: Guenter Roeck <linux@roeck-us.net>
> Tested-by: Linus Walleij <linus.walleij@linaro.org>
> Reviewed-by: Saravana Kannan <saravanak@google.com>
> Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
> ---
>  drivers/base/dd.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)

Applied to 4.19.y, but did not apply to 4.14.y or 4.9.y :(