On Fri, 2018-05-18 at 11:37 +0300, Andy Shevchenko wrote: > On Fri, 2018-05-18 at 09:48 +0200, Hans de Goede wrote: > > > > Could it be the i2c input clock definition in drivers/mfd/intel- > > lpss- > > pci.c > > is also wrong for Apollo Lake (N3450) ? There are lots of people > > having > > various issues with i2c attached touchpads on Apollo Lake devices, > > this bug: > > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1728244 > > > > Is sort of a collection bug for these. Various models laptops, lots > > of > > reporters. Note not sure thie is an i2c-designware issue, but it > > would > > be good to double check the input clock on Apollo Lake. > > > > I've checked the datasheet and the datasheet mentions 133MHz as > > "serial input clk" in the lpio_bxt_regs Registers Summary, which is > > also part of the LPSS, no clk is mentioned in the "Summary of > > DW_apb_i2c_mem_map_DW_apb_i2c_addr_block1 Registers". > > The internal datasheet we have access to mentioned in this case for > Broxton and Cannonlake together. So, your assumption might be quite > close to the truth and the issue is inherited from Broxton. > Hans, can your reporters try the following patch? Depending on the result I may send it out ASAP. --- a/drivers/mfd/intel-lpss-pci.c +++ b/drivers/mfd/intel-lpss-pci.c @@ -120,7 +120,7 @@ static struct property_entry apl_i2c_properties[] = { }; static const struct intel_lpss_platform_info apl_i2c_info = { - .clk_rate = 133000000, + .clk_rate = 216000000, .properties = apl_i2c_properties, }; -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy
