> -----Original Message----- > From: Nishanth Menon [mailto:nm@xxxxxx] > Sent: Friday, October 23, 2009 4:40 AM > Imberton Guilhem-gimb01 had written, on 10/22/2009 04:04 PM, > the following: > > I have one small comment on the actual implementation > >> + do { > >> + value = prm_read_mod_reg(OMAP3430_GR_MOD, > >> + > OMAP3_PRM_VC_BYPASS_VAL_OFFSET) > >> + & OMAP3430_VALID; > >> + /* should i wait? */ > >> + if (value && (count % 50)) > >> + udelay(10); > >> + count--; > >> + *timeout_us -= 5; > >> + } while (value && count); > > > > Why are you removing 5us every read ? > Thanks for catching this. Yep, I have got my counters mixed > up :(.. will > add it as part of v2 for tomorrow evening with other > potential comments > if any. > > > If 50 iteration is 1us and we delay every loop by 10us we > should remove 11us > > > > Shouldn't it be: > > > > + do { > > + value = prm_read_mod_reg(OMAP3430_GR_MOD, > > + > OMAP3_PRM_VC_BYPASS_VAL_OFFSET) > > + & OMAP3430_VALID; > > + /* should i wait? */ > > + if (value && (count % 50)) { > > + udelay(10); > > + *timeout_us -= 11; > > + } > > + count--; > > + } while (value && count); > > > here is a problem with the above logic: > a) I dont know for sure if 50 iterations == 1 uSec. > b) count = timeout*5 > ==> if function is called with timeout = 10 uSec, count = 50, and > udelay(10) will be called once. now *timeout -=11 will make it a > negative value, which is not helpeful. > > so, the decrement has to be by 10 OR i can pad timeout_us .. > not exactly > useful either.. Your right negative value wont be good Let's use 10uSec (50 registers reading remains realy small amount of time) And it will anyway give us a good idea of the time spent here > -- > Regards, > Nishanth Menon > Regards, Guilhem -- 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
