Date: Thu, 6 Aug 2026 11:39:41 -0700
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: linux-input@vger.kernel.org
Cc: Andrew Duggan <aduggan@synaptics.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Input: synaptics-rmi4 - fix GPF in suspend and resume
 when unbound
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References: <anQe8UiyUR4x0flD@google.com>
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On Wed, Aug 05, 2026 at 10:44:23PM -0700, Dmitry Torokhov wrote:
> Transport drivers (such as rmi_i2c and rmi_spi) invoke
> rmi_driver_suspend() and rmi_driver_resume() on their child rmi_dev
> device during system power management events. However, transport drivers
> are fully registered and operational even if the physical RMI driver
> failed to bind or probe the rmi_dev device.
> 
> When rmi_driver_suspend() or rmi_driver_resume() is called on an unbound
> rmi_dev, dev_get_drvdata() returns NULL. Calling rmi_disable_irq() or
> rmi_enable_irq() without driver data attached causes a NULL pointer
> dereference and General Protection Fault when attempting to lock
> data->enabled_mutex.
> 
> Fix this by checking if driver data is attached to rmi_dev in
> rmi_driver_suspend() and rmi_driver_resume(), exiting early if
> no driver data is present.

Note that better fix would be to have RMI driver implement PM methods
(suspend, resume) but that requires more careful planning, especially
around RMI-HID.

Thanks.

-- 
Dmitry