From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 85D058F6A; Fri, 13 Sep 2024 17:53:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726250025; cv=none; b=aKg4GwIDEo/BRsxa2d/La8D/9FNF3KMQ71QOuKaLZPKVtQPkpnpE380xVralv2wQmO99bY2ttFgm7yBl6SDVDo1MqR7YKTS6RzXtug8t5P6lwLZavzVTO8NQGow+fnx+hM8R2qV/8CMbU4BranOb3hsVbFTFl/iqwRZrlhLUWrw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726250025; c=relaxed/simple; bh=dF4UvyQtVTZgCLe2Wz+2rrKiqMSg3aXnfOSK2lhFzLo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NhO104YRmfw6PAd1z4LPdD8P/XnZRA1yMFkUvYPRi6f5fVNkL0i6Oz2Ycah0xe5nwsPda8GKJZYk+MQSi0goMW5sNSBg2IuzIZJe3bX+UA2pf1D4xUGQc8nyY13alc9k2O608QUt8cvnpiYb0knse9/7kjS+6OthTCZfFV0CApo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dgMo7YC2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dgMo7YC2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B6911C4CEC0; Fri, 13 Sep 2024 17:53:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726250025; bh=dF4UvyQtVTZgCLe2Wz+2rrKiqMSg3aXnfOSK2lhFzLo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dgMo7YC2ckDMwBZsN3oddaGz9KR+HcOXi8HK3oNr1dxTF1SGa6aW+xoKdJ2k8Gkid Dq80SdmiO2UtCC9QVDjmGPGdkajjvU2MPNUhB6Wj3o9owrc1GjskuzEY+sAeXwjk7A sxEIWE7Id/hVdchsuME6TJSrVlYm55gBViZhhtwGlJ64x9lyON5rnjfdKz8gvd184L gGrw5KB3RppdTPQQ0SuOIEi5EDhZuZmIfEo7Vru39ZqrmELuhQ+NFbzBPzvfIFu8wZ Y6p5sEWniX9ar8pP8nA8Rau94TiKoDEMOICTtFhXLRzrvPx5jyCkX3axfQvCUaJsgV dTs+eJ+LsH7PQ== Date: Fri, 13 Sep 2024 18:53:41 +0100 From: Conor Dooley To: "Wojciech Siudy (Nokia)" Cc: "linux-i2c@vger.kernel.org" , "devicetree@vger.kernel.org" , Peter Rosin , Andi Shyti , "laurent.pinchart@ideasonboard.com" Subject: Re: [PATCH v4 0/2] pca954x: Add DT bindings and driver changes for reset after timeout Message-ID: <20240913-retaining-require-59ff15d696e9@spud> References: Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="lzmOt9CzUvTyDX9b" Content-Disposition: inline In-Reply-To: --lzmOt9CzUvTyDX9b Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Sep 13, 2024 at 10:36:43AM +0000, Wojciech Siudy (Nokia) wrote: > From: Wojciech Siudy >=20 > The pca954x mux might not respond under certain cicumstances, like device= behind > it holding SDA after recovery loop or some internal issue in mux itself. = Those > situations are indicated by ETIMEDOUT returned from I2C transaction attem= pting > selecting or deselecting the channel. According to device documentation t= he > reset pulse restores I2C subsystem of the mux and deselects the channel. >=20 > Since the mux switches using transistors, the failure of line behind mux = that > is currently conneted prevents sending commands to mux itself, so externa= l reset > signal is required.=20 >=20 > The following series of patches implements the reset functionality if it = was > selected in devicetree, beceuse the reset line might not be dedivated in = some > applications and such reset pulse would break other chips. FYI, something went a bit wrong with this series, and it has not been threaded correctly. How did you send it? --lzmOt9CzUvTyDX9b Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZuR8JQAKCRB4tDGHoIJi 0qTxAQDbx1zjAQv/JN4Izv5B70lr4crUplxACCkqRG1gud1MeQEAjE2GTx90mYoZ CAGT2YZ9m5GmcooJKoRcKROtgL4tAQE= =wwuu -----END PGP SIGNATURE----- --lzmOt9CzUvTyDX9b--