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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 4/4] i2c: designware: Handle active slave cleanly
Date: Tue, 5 May 2026 10:34:46 +0300	[thread overview]
Message-ID: <afmdlt_AE1wb5wqx@ashevche-desk.local> (raw)
In-Reply-To: <20260504-dw-i2c-v3-4-57e56135d602@wkennington.com>

On Mon, May 04, 2026 at 08:15:05PM +0000, William A. Kennington III wrote:
> When the I2C master attempts a new transaction while the slave
> controller is shutting down or restarting, it can lead to bus lockups
> and system bootloops if the hardware enters an inconsistent state.
> 
> Address this by ensuring that the internal state machines are properly
> cleared when disabling the controller if slave activity is detected.
> 
> If the controller remains active after disabling, perform a bus recovery
> to reset it to a known good state.

...

>  #define DW_IC_STATUS_ACTIVITY			BIT(0)
>  #define DW_IC_STATUS_TFE			BIT(2)
>  #define DW_IC_STATUS_RFNE			BIT(3)
> -#define DW_IC_STATUS_MASTER_ACTIVITY		BIT(5)
> -#define DW_IC_STATUS_SLAVE_ACTIVITY		BIT(6)
> +#define DW_IC_STATUS_MASTER_ACTIVITY	BIT(5)
> +#define DW_IC_STATUS_SLAVE_ACTIVITY	BIT(6)

If you wish to fix some indentation issues, combine these with the one from the
second patch and make it a separate change (as a last patch in the series).

>  #define DW_IC_STATUS_MASTER_HOLD_TX_FIFO_EMPTY	BIT(7)

-- 
With Best Regards,
Andy Shevchenko



  reply	other threads:[~2026-05-05  7:34 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
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 [this message]
2026-05-05  7:35 ` [PATCH v3 0/4] i2c: designware: Improve device disable handling Andy Shevchenko

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