> -----Original Message----- > From: johnstul.lkml@xxxxxxxxx [mailto:johnstul.lkml@xxxxxxxxx] On Behalf Of john stultz > Sent: Tuesday, December 28, 2010 5:27 AM > To: Guan Xuetao > Cc: linux-arch@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCHv1 09/12] unicore32 core architecture: timer and time > > 2010/12/25 Guan Xuetao <guanxuetao@xxxxxxxxxxxxxxx>: > > From: Guan Xuetao <guanxuetao@xxxxxxxxxxxxxxx> > > > > Patch 9 implements timer and time. RTC and PWM device drivers are also here. > > > > Signed-off-by: Guan Xuetao <guanxuetao@xxxxxxxxxxxxxxx> > > Just a small request: > > > +static struct clocksource cksrc_puv3_oscr = { > > + .name = "oscr", > > + .rating = 200, > > + .read = puv3_read_oscr, > > + .mask = CLOCKSOURCE_MASK(32), > > + .shift = 18, > > Drop the shift assignment here. > > > + cksrc_puv3_oscr.mult = > > + clocksource_hz2mult(CLOCK_TICK_RATE, cksrc_puv3_oscr.shift); > > + > Drop the mult assignment here. > > > > + clocksource_register(&cksrc_puv3_oscr); > > Use "clocksource_register_hz(&cksrc_puv3_oscr, CLOCK_TICK_RATE );" and > the kernel will fill in mult/shift appropriately. > > If you have any troubles after doing so, let me know. When using clocksource_register_hz(&cksrc_puv3_oscr, CLOCK_TICK_RATE ), the shift value become 0, and mult value become 0x838a91a7, and the system will be broken after printing "Switching to clocksource oscr". When using clocksource_register_khz(&cksrc_puv3_oscr, CLOCK_TICK_RATE ), the shift value become 0, and mult value become 0x4359611, and the system will run smoothly, but timer interrupt seems too frequently. Perhaps it is 4 times faster. For comparison, originally, when shift value is set to 0x12, the mult value become 1175e5e. Which one is better? > > thanks > -john Thanks john. Guan Xuetao -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
