Since getting my Galaxy S2 back from repairs about a week ago, I thought I would give it a few days on Stock Samsung Touchwiz before I flashed CM9 or CM10 onto it but that never happened. I did not even last a day. Before 24 hours were up, my phone was back on JellyBean aka CM10 and there was no turning back. At the time of writing, the CM10 for Galaxy S2 I9100 is more or less good enough to be used as your daily driver. However, that is not to say that it is without bugs,
some most of which can be blamed on Samsung not releasing their codes or adequate references/sample codes. If you happen to visit the Galaxy S2 I9100 CM10 thread over at XDA-Developers, the one thing that you surely would have noticed is that one of the most common bug that people are talking about are RIL crashes (aside from all the other nonsense like “Oh no. My phone is bootloop after flashing Siyah”).
For those not in the know, a RIL (Radio Interface Layer) crash is what happens when you suddenly, and for no apparent reason, lose your network signal. If you happen to be looking at your phone when it happens, you may notice the empty triangle instead of your usual blue network signal indicator. For some people, this empty triangle lasts until the phone is rebooted, for others, the phone manages to sort itself out within a few seconds and the blue network signal indicator comes back. For the lucky ones, they never see this at all (this includes the devs). As far as the devs can tell, there seem to be some timing conditions which causes this to happen more frequently/infrequently on some phones rather than others.
With that being said, I do believe that this issue is more noticeable if you have a SIM pincode set. The loss of the radio signal will prompt you to re-enter your SIM pincode and that is how it is normally noticed by many. I do not use a SIM pincode and I didn’t really notice any RIL crash issues when testing out a much earlier version of CM10. I was happily led to believe that I do not experience any RIL crashes. However, that does not seem to be true. After flashing the official nightly dated October 14th, I did notice signal loss on occasions. In my case, signal always was restored a few seconds after the crash, so if it happens at times when I wasn’t actively looking at the screen, I had no way of knowing whether a RIL crash happened.
Reading through the XDA-Developers thread, I found a useful post by forum member Dannius. In his post, he describes using an App named Tasker to automate the capturing of logcats and even sounding an alarm when the RIL crash happens. Intrigued, I decided to give it a try to see if my phone was having RIL crashes without me knowing. After some early trial and errors, I managed to have Tasker set up the way I want it. Once done, I discovered that in within an hour, my phone can have as many as 3 RIL crashes! This was all on the October 14th Nightly build of CM10.
Developer espenfjo had uploaded a few experimental builds which was aimed at helping to give more insight to the developers regarding the issue. I tried one of them, the SILENCE-HSIC-LINK-2 build and managed to capture a few logcats over the course of the next day. Soon after that, I switched over to the STABILITYTEST build (available on get.cm). While the STABILITYTEST build does not fully get rid of the RIL crashes for me (unlike for some lucky folks), it did reduce the frequency of crashes. Plus, the STABILITYTEST build also has the CM’s circle battery mod which I wanted to try out (looks quite nice). Some folks over in Spain is claiming that a certain 250K or 250S RIL+LPO modem combo from Korea helps them get a better, more stable signal and they have managed to go a few days without a RIL crash. I am currently on BVLP7 modem and while it is pretty stable modem, I am tempted to give the Korean combo a try (will do so in the next few days).
Since my RIL crashes usually recover by themselves within a few seconds, it is not too bad for me as opposed to those who has to reboot their phone every time. So, I would rate the current CM10 project usable. However, if you are going to try it out, please be aware that RIL crashes can and do happen to most users at one point or another. Frequency seems to increase if you are in an area of low coverage but at this point, it is an assumption and not a solid conclusion yet. Developers are still hard at work trying to resolve this issue (which is said to happen on even stock Samsung ROMs on occasion) and if you manage to capture logs, you may want to upload it to the site for the developers to take a look.
The developers like Entropy512 and Espenfjo may release several more experimental builds over the coming weeks and it is highly advisable that you do not flash these experimental builds unless you are trying to reproduce the issues and help the development. For everyone else, it may be better to stick with a build that is working for you (or maybe even reverting back to ICS aka CM9). How about you? Have you experienced RIL crashes?
If you need help or want more info (and don’t want to ask in the threads for fear of being blamed/flamed/ignored, which you shouldn’t have to worry about anyways), you can always drop me a line in the comments section and I’ll do what I can to help.