On Fri, 18 May 2018, Jarkko Nikula wrote:
Intel Cannon Lake PCH has much higher 216 MHz input clock to LPSS I2C than Sunrisepoint which uses 120 MHz. Preliminary information was that both share the same clock rate but actual silicon implements elevated rate for better support for 3.4 MHz high-speed I2C.
This incorrect input clock rate results too high I2C bus clock in case ACPI doesn't provide tuned I2C timing parameters since I2C host controller driver calculates them from input clock rate.
Fix this by using the correct rate. We still share the same 230 ns SDA hold time value than Sunrisepoint.
Cc: stable@vger.kernel.org Fixes: b418bbff36dd ("mfd: intel-lpss: Add Intel Cannonlake PCI IDs") Reported-by: Jian-Hong Pan jian-hong@endlessm.com Reported-by: Chris Chiu chiu@endlessm.com Reported-by: Daniel Drake drake@endlessm.com Signed-off-by: Jarkko Nikula jarkko.nikula@linux.intel.com
Hi Jian-Hong, Chris and Daniel. Could you test does this fix your touchpad issue?
drivers/mfd/intel-lpss-pci.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-)
Applied, thanks.