From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH 07/10] i2c: Add driver for AD242x bus controller Date: Thu, 12 Dec 2019 17:33:15 +0100 Message-ID: <20191212163315.GA3932@kunai> References: <20191209183511.3576038-1-daniel@zonque.org> <20191209183511.3576038-9-daniel@zonque.org> <64adf5d7-754a-f1da-aa9b-11579c5a2780@lucaceresoli.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="x+6KMIRAuhnl3hBn" Return-path: Content-Disposition: inline In-Reply-To: <64adf5d7-754a-f1da-aa9b-11579c5a2780@lucaceresoli.net> Sender: linux-kernel-owner@vger.kernel.org To: Luca Ceresoli Cc: Daniel Mack , linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-clk@vger.kernel.org, mturquette@baylibre.com, sboyd@kernel.org, robh+dt@kernel.org, broonie@kernel.org, lee.jones@linaro.org, lars@metafoo.de, pascal.huerst@gmail.com List-Id: linux-i2c@vger.kernel.org --x+6KMIRAuhnl3hBn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi Luca, thanks for the review! > good, but I think there's a problem in this function. A "normal" > master_xfer function issues a repeated start between one msg and the > next one, at least in the typical case where all msgs have the same > slave address. Your implementation breaks repeated start. At first sight > we might need more complex code here to coalesce all consecutive msgs > with the same address into a single i2c_transfer() call. Note that it is by far the standard case that all messages in a transfer have the same client address (99,999%?). But technically, this is not a requirement and the repeated start on the bus is totally independent of the addresses used. It is just a master wanting to send without being interrupted by another master. Wolfram --x+6KMIRAuhnl3hBn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl3ya8cACgkQFA3kzBSg KbZBdQ/6ApPjJEPmloupECtcOPxRdHIBMJSbDi9HpBk6QSvFwtknvv6ybcJHJ3Dc 2GkbUK4EAcDvvDx4mTqhw7t8JPay3Bu3O13a/wXP5PDb7DeHJ5xDaBsEYVLC9id2 E1I5aEfdrrxsL1HFUZn86BmmthMuupvelZAyfL7pXDT3AU5oNkPipfKzoiC0EiBP MPu2HN8BIX7l1ECvOL9j0pZYCfz00UHA4PtWHwz7zjiCG7RmY3qlm6xw5l6XFeq3 wbcmTXcLr8OIG/8sw0PMJjJFqHfH9Vlj8aYcRrsgjDEHQbSTKAQ/RTDw9rcmAktW /1u6RUea0ckwX6rhKWZSXVktPzCV5LWaywD6lsMGXxhF/0T2tvKRqV6+xIngUY3n 8KnzpK2i3gvLmP9BYYxa/BM8qiuR4SimZi35lmofttUzXUs/5fgJwxFg2UuJqpPD Ex/lyLc1AUbRRp8mDsSMsGg7Ku6WUt5T7OxmVjzvIYPLJ84GlTvZLA4WIskzWFVw aZ2+E4YZq35snfMfawdrDmTOOmNOEPfVuT5Cm2ul1HVTprAgF/DVkQHVWPzNtOo9 xxwPgX9lrN0I+Ek2F1kSJguphMzVjIFRvFCl77TJUQ7qvBEWYDLQs1hBdmXieBxA bNZoxeVI6DmFF5qTxkQ3Qh9NUGWkPKuslRF2Fh7dWQIoS9FauJo= =Gmcp -----END PGP SIGNATURE----- --x+6KMIRAuhnl3hBn--