From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH v1] i2c: designware: save the preset value of DW_IC_SDA_HOLD Date: Tue, 30 Aug 2016 22:59:40 +0200 Message-ID: <20160830205939.GF3645@katana> References: <1472283570-31471-1-git-send-email-zhuo-hao.lee@intel.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Pgaa2uWPnPrfixyx" Return-path: Received: from sauhun.de ([89.238.76.85]:41651 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751515AbcH3U7x (ORCPT ); Tue, 30 Aug 2016 16:59:53 -0400 Content-Disposition: inline In-Reply-To: <1472283570-31471-1-git-send-email-zhuo-hao.lee@intel.com> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: Zhuo-hao Lee Cc: jarkko.nikula@linux.intel.com, andriy.shevchenko@linux.intel.com, mika.westerberg@linux.intel.com, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org --Pgaa2uWPnPrfixyx Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Aug 27, 2016 at 03:39:30PM +0800, Zhuo-hao Lee wrote: > There are several ways to set the SDA hold time for i2c controller, > including: Device Tree, built-in device properties and ACPI. However, > if the SDA hold time is not specified by above method, we should > read the value, where it is preset by firmware, and save it to > sda_hold_time. This is needed because when i2c controller enters > runtime suspend, the DW_IC_SDA_HOLD value will be reset to chipset > default value. And during runtime resume, i2c_dw_init will be called > to reconfigure i2c controller. If sda_hold_time is zero, the chipset > default hold time will be used, that will be too short for some > platforms. Therefore, to have a better tolerance, the DW_IC_SDA_HOLD > value should be kept by sda_hold_time. >=20 > Signed-off-by: Zhuo-hao Lee Looks good. But is it a bugfix? Looks more like for-next material to me, but not sure... --Pgaa2uWPnPrfixyx Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJXxfO7AAoJEBQN5MwUoCm2lN4P/R2w8U5NAhEMccMGWaWTpesO XH24cJ8ZfKtUYVJmU9SF+lQT6/B4FhqBe2XHEC2I1wpLHCXmAkAtDx8pEdIW/Hi7 X0LXlk665u50FaTfWazB8LtW+GEgVWDvAisR3PxgxhT/8+7g5S0SRtGAT5NDRLS0 +LBWlpMUI0X9yaUevhEYlVBIDANtXa2/ZKcgiRErYKHhL1orSmEj+gexTF92zOLn pTU4Tr4mT3jdFp7qBc7ZmpyzP2A8qx9vf/PeF0ZL9ncWa2nG4TOTTzilpMHpnuMV G7abg5F/IHuc5QAyp1d0aG9nzMbmPj62UtVpXyLl5b9CI3vm3//46bSS777RcbO6 ccME1mHQ+6FAOK3OdOxftw4P4ZZCSWBcorTtpPyRhjlXt9Kx71rznXQOL72/eBsS avpaGb0TDyC+p3ZHBxkwP/w3XM6K259sIo3TBJRcLkFqsVCSFWdgr4zOlXvi+Ya4 NzTxtCj3vXnlLCWjXD0+G6Ehe+Q2GCpfZ1yN0CWmWVT7P0Vq2fFCaYI/DGbLIqs2 rURNwtKRqvPkxaWfuBtUCaeqq65aEztKanSLNpYmZVEItnsbCLXTuDxy7sn5jYEk /F+gT4440BdGcWDEiptf3PrwFjq5kterLgTPW0r25ac4WIeNaSqMibLC7g+hnCU2 1CbBvi86bgjQiuyn/2DR =WcG1 -----END PGP SIGNATURE----- --Pgaa2uWPnPrfixyx--