Hi, a few quick comments, possibly nit-picking...
On Wed, 31 Dec 2008, Woodruff, Richard wrote: > Actually, the functional spec for timer says max re-sync time is: > 3 OCP clock + 2.5 TIMER clock > 3(1/83MHz) + 76uS = ~76uS The OCP clock rate is dependent on the timer's interface clock clockdomain. On OMAP3, GPTIMER1 uses sys_clk as the OCP interface clock, so the interface portion of this delay could be as slow as 3 periods/12MHz periods = 250 ns. For GPTIMERs in CORE_L4 or PER_L4, the choice of CORE OPP will also change the OCP delay portion. The L4 bus clock rate could be as low as 20.75MHz in 34xx VDD2 OPP1; resulting in a 145 ns delay for that portion. These factors are noise with the 32KiHz timer source, but we are overusing it. In the case of Beagle, the HF clk source can't be disabled, so we should be able to use sys_ck. Same for other boards when AUTOEXTCLKMODE is disabled. In those situations we should probably take the OCP-related delay into account. - Paul -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
