On Fri, Jul 30, 2010 at 7:54 AM, Maxim Levitsky <maximlevitsky@xxxxxxxxx> wrote: > On Fri, 2010-07-30 at 07:51 -0400, Jon Smirl wrote: >> On Fri, Jul 30, 2010 at 7:36 AM, Maxim Levitsky <maximlevitsky@xxxxxxxxx> wrote: >> > On Thu, 2010-07-29 at 23:46 -0400, Andy Walls wrote: >> >> On Thu, 2010-07-29 at 22:39 -0400, Jon Smirl wrote: >> >> > On Thu, Jul 29, 2010 at 10:17 PM, Maxim Levitsky >> >> > <maximlevitsky@xxxxxxxxx> wrote: >> >> > > note that error_adjustment module option is added. >> >> > > This allows to reduce input samples by a percent. >> >> > > This makes input on my system more correct. >> >> > > >> >> > > Default is 4% as it works best here. >> >> > > >> >> > > Note that only normal input is adjusted. I don't know >> >> > > what adjustments to apply to fan tachometer input. >> >> > > Maybe it is accurate already. >> >> > >> >> > Do you have the manual for the ENE chip in English? or do you read Chinese? >> >> >> >> The datasheet for a similar chip, the KB3700, is out there in English, >> >> but it doesn't have CIR. >> >> >> >> You might find these links mildly interesting: >> >> >> >> http://www.coreboot.org/Embedded_controller >> >> http://wiki.laptop.org/go/Embedded_controller >> >> http://lists.laptop.org/pipermail/openec/2008-July/000108.html >> > >> > Nope, I have read that. >> >> >> >> Regards, >> >> Andy >> >> >> >> > Maybe you can figure out why the readings are off by 4%. I suspect >> >> > that someone has set a clock divider wrong when programming the chip. >> >> > For example setting the divider for a 25Mhz clock when the clock is >> >> > actually 26Mhz would cause the error you are seeing. Or they just made >> >> > a mistake in computing the divisor. It is probably a bug in the BIOS >> >> > of your laptop. If that's the case you could add a quirk in the >> >> > system boot code to fix the register setting. >> > >> > I figured out how windows driver compensates for the offset, and do the >> > same in my driver. I think the problem is solved. >> > >> >> Should that be a <= or >= instead of !=? >> + if (pll_freq != 1000) > > This is how its done in windows driver. That doesn't mean it is bug free. Experimenting with changing the PLL frequency register may correct the error. Try taking 96% of pll_freq and write it back into these register. This would be easy to fix with a manual. The root problem is almost certainly a bug in the way the PLLs were programmed. I don't like putting in fudge factors like the 4% correction. What happens if a later version of the hardware has fixed firmware? I normal user is never going to figure out that they need to change the fudge factor. + pll_freq = (ene_hw_read_reg(dev, ENE_PLLFRH) << 4) + + (ene_hw_read_reg(dev, ENE_PLLFRL) >> 2); + >> >> Programming the PLL wrong would cause the 4% error. >> >> hw_revision = ene_hw_read_reg(dev, ENE_HW_VERSION); >> old_ver = ene_hw_read_reg(dev, ENE_HW_VER_OLD); >> >> + pll_freq = (ene_hw_read_reg(dev, ENE_PLLFRH) << 4) + >> + (ene_hw_read_reg(dev, ENE_PLLFRL) >> 2); >> + >> + if (pll_freq != 1000) >> + dev->rx_period_adjust = 4; >> + else >> + dev->rx_period_adjust = 2; >> + >> + >> + ene_printk(KERN_NOTICE, "PLL freq = %d\n", pll_freq); >> + >> if (hw_revision == 0xFF) { >> >> >> >> > >> > Best regards, >> > Maxim Levitsky >> > >> > >> >> >> > > > -- Jon Smirl jonsmirl@xxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
