On 6/26/19 3:48 PM, Marek Vasut wrote: > On 6/26/19 2:45 PM, Melin Tomas wrote: >> On 6/26/19 3:26 PM, Marek Vasut wrote: >>> On 6/26/19 2:19 PM, Melin Tomas wrote: >>>> On 6/26/19 2:49 PM, Marek Vasut wrote: >>>>> On 6/26/19 1:25 PM, Melin Tomas wrote: >>>>>> On 6/26/19 1:47 PM, Marek Vasut wrote: >>>>>> >>>>>>> On 6/26/19 12:39 PM, Melin Tomas wrote: >>>>>>> >>>>>>>> As such, it's probably a good idea to keep the same delay values here >>>>>>>> as >>>>>>>> in the original driver unless good reason to use something else. >>>>>>>> >>>>>>>> As what goes for the original reasoning for 3ms, the commit history >>>>>>>> does >>>>>>>> not mention that so I cannot comment. >>>>>>> So would you be so kind and research this ? >>>>>> Based on a short study of other i2c bus drivers it seems most have bus >>>>>> busy timeout checks. >>>>>> >>>>>> The timeout values seems to differ, ranging from milliseconds to seconds. >>>>> Yep >>>>> >>>>>> So probably it's just a number, after all it's just a check to know if >>>>>> we are good to go. >>>>> And is the number large enough ? >>>> As mentioned, good approach is probably using value known to work >>>> instead of >>>> >>>> guessing a new number. >>> So why did kernel pick that specific number ? Surely there was some >>> reasoning, they didn't just pull it out of /dev/random . >> Yes, history does not tell. >> >> I do see that this driver uses timeout of 1000ms for bus busy when >> probing, perhaps you can enlighten how that number was concluded? If >> that could give some clues about this. > I don't know.
But you are author of that line? > You're the patch author, it's your responsibility to know why you're > adding/changing the code you're adding/changing. yes, and the reasoning is: * the value has been deemed good in original driver. If it would be bad, probably it would have been changed during course of time * the value has been tested for this driver as well with success thanks, Tomas _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
