From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Artem Shimko <a.shimko.dev@gmail.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>,
Jan Dabros <jsd@semihalf.com>, Andi Shyti <andi.shyti@kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i2c: designware: add reset control support in suspend/resume
Date: Tue, 10 Mar 2026 21:22:39 +0200 [thread overview]
Message-ID: <abBvf9HgLeCpjevu@ashevche-desk.local> (raw)
In-Reply-To: <20260310184046.2010403-1-a.shimko.dev@gmail.com>
On Tue, Mar 10, 2026 at 09:40:45PM +0300, Artem Shimko wrote:
> The driver currently acquires reset control during probe but does not
> manage it during system suspend/resume. This can leave the I2C controller
> in an undefined state after resume.
>
> Add reset control assertion during system suspend and deassertion during
> resume to ensure proper hardware initialization across power management
> transitions. Skip runtime suspend if the device is already suspended to
> avoid redundant operations.
...
> +#ifdef CONFIG_ACPI
Why?
> static int i2c_dw_prepare(struct device *device)
> {
> /*
> */
> return !has_acpi_companion(device);
> }
> +#endif
...
> EXPORT_GPL_DEV_PM_OPS(i2c_dw_dev_pm_ops) = {
> +#ifdef CONFIG_ACPI
> .prepare = pm_sleep_ptr(i2c_dw_prepare),
> LATE_SYSTEM_SLEEP_PM_OPS(i2c_dw_suspend, i2c_dw_resume)
> +#else
> + SYSTEM_SLEEP_PM_OPS(i2c_dw_suspend, i2c_dw_resume)
> +#endif
Why?
Usually we try to avoid _adding_ ugly ifdeffery. Can you elaborate why the
change is needed in the first place and why there is no better way to handle
it?
> RUNTIME_PM_OPS(i2c_dw_runtime_suspend, i2c_dw_runtime_resume, NULL)
> };
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2026-03-10 19:22 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-10 18:40 Artem Shimko
2026-03-10 19:22 ` Andy Shevchenko [this message]
2026-03-11 6:20 ` Artem Shimko
2026-03-11 12:10 ` Andy Shevchenko
2026-03-23 7:42 ` Artem Shimko
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