public inbox for linux-i2c@vger.kernel.org
 help / color / mirror / Atom feed
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: "William A. Kennington III" <william@wkennington.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>,
	Jan Dabros <jsd@semihalf.com>, Andi Shyti <andi.shyti@kernel.org>,
	linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 1/4] i2c: designware: Introduce shutdown exported function
Date: Tue, 5 May 2026 10:29:57 +0300	[thread overview]
Message-ID: <afmcdXJt9X0Y3mw3@ashevche-desk.local> (raw)
In-Reply-To: <20260504-dw-i2c-v3-1-57e56135d602@wkennington.com>

On Mon, May 04, 2026 at 08:15:02PM +0000, William A. Kennington III wrote:
> Introduce an exported shutdown function to safely shutdown the
> DesignWare I2C controller.
> 
> This shutdown hook gracefully sets the slave disable bit before disabling
> the controller. This guarantees that any incoming requests from the master
> are immediately NACKed during shutdown, preventing the bus from hanging.

...

> +void i2c_dw_shutdown(struct dw_i2c_dev *dev)
> +{
> +	unsigned int con;
> +
> +	/*
> +	 * We only need to handle shutdown for slave mode to ensure
> +	 * we NACK any incoming master requests. Master mode cleanup
> +	 * is handled after each transfer in i2c_dw_xfer.

i2c_dw_xfer()

> +	 */

Since it's a newly added comment, can you switch to use inclusive language?
Same for the whole series related to the commit messages, comments, and
documentation.

> +	if (dev->mode != DW_IC_SLAVE)
> +		return;
> +
> +	/*
> +	 * To quickly NACK the master during shutdown, we set the slave
> +	 * disable bit while the controller is still enabled.
> +	 */
> +	regmap_read(dev->map, DW_IC_CON, &con);
> +	con |= DW_IC_CON_SLAVE_DISABLE;
> +	regmap_write(dev->map, DW_IC_CON, con);
> +
> +	i2c_dw_disable(dev);
> +}

> +EXPORT_SYMBOL_GPL(i2c_dw_shutdown);

Can we use namespace?

...

>  void __i2c_dw_disable(struct dw_i2c_dev *dev);
>  void i2c_dw_disable(struct dw_i2c_dev *dev);

> +void i2c_dw_shutdown(struct dw_i2c_dev *dev);

Isn't more tighten to the probe/remove than this?

>  extern void i2c_dw_configure_master(struct dw_i2c_dev *dev);
>  extern int i2c_dw_probe_master(struct dw_i2c_dev *dev);

-- 
With Best Regards,
Andy Shevchenko



  reply	other threads:[~2026-05-05  7:30 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-04 20:15 [PATCH v3 0/4] i2c: designware: Improve device disable handling William A. Kennington III
2026-05-04 20:15 ` [PATCH v3 1/4] i2c: designware: Introduce shutdown exported function William A. Kennington III
2026-05-05  7:29   ` Andy Shevchenko [this message]
2026-05-04 20:15 ` [PATCH v3 2/4] i2c: designware: Convert PCI driver to use shutdown hook William A. Kennington III
2026-05-05  7:31   ` Andy Shevchenko
2026-05-04 20:15 ` [PATCH v3 3/4] i2c: designware: Convert platform " William A. Kennington III
2026-05-05  7:31   ` Andy Shevchenko
2026-05-04 20:15 ` [PATCH v3 4/4] i2c: designware: Handle active slave cleanly William A. Kennington III
2026-05-05  7:34   ` Andy Shevchenko
2026-05-05  7:35 ` [PATCH v3 0/4] i2c: designware: Improve device disable handling Andy Shevchenko

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=afmcdXJt9X0Y3mw3@ashevche-desk.local \
    --to=andriy.shevchenko@linux.intel.com \
    --cc=andi.shyti@kernel.org \
    --cc=jsd@semihalf.com \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mika.westerberg@linux.intel.com \
    --cc=william@wkennington.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox