From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Nikula Subject: Re: [BUG] i2c-hid: ELAN Touchpad does not work on ASUS X580GD Date: Thu, 17 May 2018 10:48:14 +0300 Message-ID: References: <7728da79-8a7a-b87d-d09c-b36978b3032e@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <7728da79-8a7a-b87d-d09c-b36978b3032e@linux.intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Chris Chiu Cc: Daniel Drake , Jian-Hong Pan , Jiri Kosina , Benjamin Tissoires , Jani Nikula , Hans de Goede , Dmitry Torokhov , Adrian Salido , Jason Gerecke , linux-input , Andy Shevchenko , Mika Westerberg , Wolfram Sang , linux-i2c@vger.kernel.org, Linux Kernel , Linux Upstreaming Team List-Id: linux-input@vger.kernel.org Hi On 05/15/2018 01:20 PM, Jarkko Nikula wrote: > On 05/15/2018 06:22 AM, Chris Chiu wrote: >> What if I change the 120MHz to 180MHz and then make sure that the I2C >> operates >> in target FS mode frequency 400kHz via scope? Would there be any side >> effect? >> Maybe some other busses frequency could be also affected and causing >> some other >> component malfunction? >> > Should be safe. It is only clock rate information when registering a > fixed clock with known rate in intel-lpss.c and i2c-designware uses that > info when calculating the timing parameters. I.e. it doesn't change any > internal clocks. > > I'm trying to find a contact who can confirm what is the expected rate > of I2C input clock and is it common to all Cannon Lake HW. > I got confirmation that input clock is actually even higher 216 Mhz. While checking does it cover all of those CNL CNL-LP and CNL-H PCI IDs may I add your Jian-Hong, Chris and Daniel email addresses to Repored-by tags in a fix patch? -- Jarkko