Re: [PATCH v5] i2c: imx: mark I2C adapter when hardware is powered down

Andi Shyti <[email protected]> Tue, 28 Jul 2026 17:35:27 +0200
Newsgroups org.kernel.vger.linux-i2c,dev.linux.lists.imx,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel,org.kernel.vger.stable
Message-ID <[email protected]>
Hi Carlos,

On Mon, May 25, 2026 at 11:04:00AM +0800, Carlos Song (OSS) wrote:
> From: Carlos Song <[email protected]>
> 
> On some i.MX platforms, certain I2C client drivers keep a periodic
> workqueue which continues to trigger I2C transfers.
> 
> During system suspend/resume, there exists a time window between:
>   - suspend_noirq and the system entering suspend
>   - the system starting to resume and resume_noirq
> 
> In this window, the I2C controller resources such as clock and pinctrl
> may already be disabled or not yet restored.
> 
> If a workqueue triggers an I2C transfer in this period, the driver
> attempts to access I2C registers while the hardware resources are
> unavailable, which may lead to system hang.
> 
> Mark the I2C adapter as suspended during noirq suspend and block new
> transfers until resume, ensuring that I2C transfers are only issued
> when hardware resources are available.
> 
> Fixes: 358025ac091e ("i2c: imx: make controller available until system suspend_noirq() and from resume_noirq()")
> Cc: [email protected]
> Signed-off-by: Carlos Song <[email protected]>

merged to i2c/i2c-fixes.

Thanks,
Andi