[SOLVED] The accuracy of the function get_rtc_time()

Mohammad Abdelhadi · 10-24-2010, 08:32 AM

Hi,

I am trying to get the time of my wall clock from my wireless driver in form of "hh:mm:ss", so I used the function get_rtc_time() inside my driver to get that and it was done.
My question: Is it possible to increase the accuracy of this function, for example if I want to get the milliseconds and the Microseconds in additional to the first output?
If not, Is there any other function can do that?

the desired form is "hh:mm:ss:ms:us"

Thank you,

--Mohammad

paulsm4 · 10-25-2010, 12:58 AM

You can *get* microseconds ...
... but that doesn't mean that the number you get will be accurate.

It won't

Suggestion: gettimeofday ()

'Hope that helps

alan99 · 10-25-2010, 10:00 PM

Quote:

Originally Posted by Mohammad Abdelhadi

Hi,

I am trying to get the time of my wall clock from my wireless driver in form of "hh:mm:ss", so I used the function get_rtc_time() inside my driver to get that and it was done.
My question: Is it possible to increase the accuracy of this function, for example if I want to get the milliseconds and the Microseconds in additional to the first output?
If not, Is there any other function can do that?

the desired form is "hh:mm:ss:ms:us"

Thank you,

--Mohammad

What do you mean wall clock? Is your computer mounted on the wall? Do you mean one of those wall clocks synchronized to a radio time standard? get_rtc_time is a kernel function call and is only as good as the hardware clock in your computer, which may be off a few seconds everyday, unless that is you have it synchronized to a NTP server. You will never get microsecond accuracy unless you have special hardware synchronized to a GPS receiver or an atomic clock. That would be very expensive.

Mohammad Abdelhadi · 10-26-2010, 02:38 PM

Hi,

Thank you all for the replies,

Well, lets say that I want to increase the resolution of the time that I get from my clock, that's it!

I used the function do_gettimeofday() to get the time in microseconds.

--Mohammad