Hi Allen, On Thu, 21 Jan 2010, Pais, Allen wrote: > This patch disables GAIA I2C1 adn I2C4(SR) internal pull-up, to > use only the external HW resistor >=470 Ohm for the assured > functionality in HS mode. > > While testing the I2C in High Speed mode, it was discovered that > without a proper pull-up resistor, there is data corruption during > multi-byte transfer. RTC(time_set) test case was used for testing. > > >From the analysis done, it was concluded that ideally we need a > pull-up of 1.6k Ohm(recomended) or atleast 470 Ohm or greater for > assured performance in HS mode. A few more questions. 1. Does this patch also apply to other TI PMICs, e.g., Triton2, Reno, etc? 2. It sounds like, from the patch description, that HS I2C mode is not reliable on boards without external pullups. Shouldn't this patch (or one in the same series) provide some way for mach-omap2/board-*.c files to indicate this to the I2C code, such that HS I2C can be disallowed on those boards? Similarly, for SmartReflex, which has an internal I2C controller but does not use the OMAP I2C driver code, shouldn't there be a similar mechanism for that code? - Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
