From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: Regression: bd698d24b1b57: i2c: designware: Get selected speed mode sda-hold-time via ACPI Date: Tue, 09 May 2017 17:54:11 +0300 Message-ID: <1494341651.30052.82.camel@linux.intel.com> References: <20170509140720.GA21122@red-moon> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20170509140720.GA21122@red-moon> Sender: linux-acpi-owner@vger.kernel.org To: Lorenzo Pieralisi , chin.yew.tan@intel.com, mika.westerberg@linux.intel.com, jarkko.nikula@linux.intel.com Cc: wsa@the-dreams.de, linux-acpi@vger.kernel.org, linux-i2c@vger.kernel.org, Ard Biesheuvel List-Id: linux-i2c@vger.kernel.org On Tue, 2017-05-09 at 15:07 +0100, Lorenzo Pieralisi wrote: > Hi guys, > > as a heads-up, with today mainline (commit 2868b2513aa7) I get the > following splat on AMD Seattle, reverting the $SUBJECT commit "solves" > the problem. > > My I2C knowledge is a bit limited but I am not sure I understand why > we should be reading eg ss_hcnt/ss_lcnt depending on the dev->clk_freq > but then i2c_dw_init() _always_ requires those values to be set for > a given device. Again, I have no insights into I2C inner workings > so apologies for the silly assumption/question. > > Please have a look into this, thanks. Since there is no clock defined you got a warning. It means either ID is not added to drivers/acpi/acpi_apd.c or platform has wrong values and thus dw_i2c_no_acpi_params should be expanded. I have no such platform, so I can't tell which one is the right fix. But it's not a revert by my opinion. > [    1.160597] ------------[ cut here ]------------ > [    1.165207] WARNING: CPU: 0 PID: 1 at drivers/i2c/busses/i2c- > designware-core.c:293 i2c_dw_clk_rate+0x20/0x30 > -- Andy Shevchenko Intel Finland Oy