On Mon, 2017-02-13 at 11:33 +0200, Jarkko Nikula wrote: > On 13.02.2017 10:41, Tan, Chin Yew wrote: > > > > > On Fri, 2017-02-10 at 19:28 +0800, chin.yew.tan@xxxxxxxxx wrote: > > > > From: Tan Chin Yew <chin.yew.tan@xxxxxxxxx> > > > > > > > > Sda-hold-time is an important parameter for tuning i2c to meet > > > > the > > > > electrical specification especially for high speed. I2C with > > > > incorrect > > > > sda-hold-time may cause lost arbitration error. Now, the driver > > > > is > > > > able to get sda-hold-time for all the speed supported. > > > > + case 1000000: > > > > + dw_i2c_acpi_params(pdev, "FPCN", &dev->fp_hcnt, > > > > &dev- > > > > > fp_lcnt, > > > > > > > > + &dev->sda_hold_time); > > > > + break; > > > > + case 3400000: > > > > + dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, > > > > &dev- > > > > > hs_lcnt, > > > > > > > > + &dev->sda_hold_time); > > > > + break; > > > > > > Can we prepend default with > > > > > > case 400000: > > > > > > here? > > > > > > > Yes, you are right, it is best not to load settings for speed mode > > that is > > not supported. > > > > Andy: I guess you were looking for adding "case 400000:" for > readability > rather than removing the default case? Correct. To explicitly show that default we rather assume 400000, but if it's not, still go that branch. > > I think it's best to keep fall back to 400 kHz speed that has been > the > default in this driver in case we get some not supported speed from > ACPI. -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
