Linux GPIO subsystem development
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From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: Markus Stockhausen <markus.stockhausen@gmx.de>
Cc: andi.shyti@kernel.org, linusw@kernel.org, brgl@kernel.org,
	linux-i2c@vger.kernel.org, linux-gpio@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v7 1/2] i2c: algo: bit: Allow to skip bit test
Date: Wed, 15 Jul 2026 22:31:44 +0200	[thread overview]
Message-ID: <alfuMKlJqXD-YEMb@ninjato> (raw)
In-Reply-To: <20260714162915.3018703-2-markus.stockhausen@gmx.de>

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On Tue, Jul 14, 2026 at 06:29:14PM +0200, Markus Stockhausen wrote:
> An I2C bus can make use of shared resources. E.g. two GPIO based buses
> that share a single SCL line. To synchronize access to the bus the driver
> might use locking with the help of i2c_lock_operations(). While this
> works for normal transfers it is not available during initialization.
> 
> Especially if i2c-algo-bit module is loaded with parameter bit_test
> it will issue some basic sanity checks that will access the bus without
> locking. This might interfere badly with concurrent transfers. Even
> if these are well synchronized via locks.
> 
> Allow the consumer of an algorithm to override if the bit_test is allowed
> or not. For this add a new boolean attribute named skip_bit_test to
> i2c_algo_bit_data. If set the test is not run.
> 
> Signed-off-by: Markus Stockhausen <markus.stockhausen@gmx.de>

Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>


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  reply	other threads:[~2026-07-15 20:31 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-14 16:29 [PATCH v7 0/2] i2c: i2c-gpio: Enhance driver for buses with shared SCL Markus Stockhausen
2026-07-14 16:29 ` [PATCH v7 1/2] i2c: algo: bit: Allow to skip bit test Markus Stockhausen
2026-07-15 20:31   ` Wolfram Sang [this message]
2026-07-14 16:29 ` [PATCH v7 2/2] i2c: i2c-gpio: Enhance driver for buses with shared SCL Markus Stockhausen
2026-07-15 20:36   ` Wolfram Sang
2026-07-15  6:26 ` AW: [PATCH v7 0/2] " Markus Stockhausen
2026-07-15  6:44   ` Wolfram Sang

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