Make Qualcomm platform Android Drive Testimonials

The second time to write this kind of blog, before the job is written during the interview and other experiences.

Unconsciously do the drive again2a month is3years, it can be said that this3years to learn a lot, the boss or colleagues of the advice, targeted through Baidu and other search, there is their own side of the work on their own research. Knowledge, the ability to solve problems is also slowly accumulated. For more than two years has been doing the drive, starting from start contact CommissioningLCD TPand so on, each time will be repeated work, but I learned a lot, learn to analyze the key issues, master some of the driving debugging methods, in fact, the debug drive for aPRINTKreally enough, again powerful but, debugging too high passModemside code after discoveryKernelhow good it is to debug. Re-commissioningLCDin the first study to understand some of the platform operationDisplaythe process andKernelbacklight operation, then solve the problem is very skilled. The harder part is debugging.QCTof theLKinside theLCDDisplay and BootlogoKeep, theseThe feeling is very stressful for the first time to start a drive, and during theDelayto debugLKwith theKerneljust starting to come up with the problem, than with saying inLKinsideLogO Disappear orKerneljust started to disappear, debugging onceLCD LK Displaynot bright after the back or other problems are well solved, of course, isQCT, commissioningQrdIt's a lot easier.,The main problem is less。 Display problems when starting up useDelayIt is very good to check, some may say the serial output, but the practice provesDelayis the most practical. Of course, the serial output debugging is really good, such as the freezing and so on, very powerful, personal feeling as long as can outputLog, it is difficult to solve the problem. ForTP, no more than sample escalation, belongs toI²cThe device also belongs toinputequipment, more was met during commissioningFae optimized anti-jamming and reporting points, sleep currents, wake-up can not work and other problems. ComparedLCDsimple and much more. EngageLCD TPalmost, the feeling is well mastered, the problem can be solved quickly, and then thechargewith theBatt,and it's going to be like sleeping., has been engaged in power management in the back.chargewith theBattPersonal feeling functionOKafter the follow-up or need to be slowly optimized during the trial period, especially the problem of electricity inaccuracy, doQCTThere's been a plug in .Chargerafter the problem can not be charged, there are many other problems, the amount of prenatal will slowly appear, personal feel as long as familiarLinux Powerpart of the solution is not difficult, or that sentenceLinux kernelproblems arise as a result ofPRINTKThe easiest to solve, unless it's a hardware problem. Yes drivers and hardware often accuse each other when there is a problem. BesidesCamera, only remember the first year of the Qualcommrealeaseout of a Sensemodule, there is a need to be transplanted in other platforms, the commissioning process is nothing but power, pull downRST, null pointers appear in the transplant, etc., after solving the problems encounteredCameraIt will eventually light up and, of course, needtunning. It's a very laborious job, and it's time-consuming. Haven't done it in the future.Camera, I think we should continue to studyLinux kernelinside for good, after all is to do the drive, and not go in order toCameraeffect has been goingtunning. Tunning need special people to do, once the special tunning will be very difficult to have time to do other work. Of course some companies givetunnning Camerathe treatment is very good, even so I will not be tempted to go deep into this piece. Personal hobbies, etc. are not the same, the back has been focused onLinux kernel.

          The company does not only do mobile phones will also integrate other modules, so that the development of a mobile phone than a lot of difficulty, a lot of things themselves have to study. such as the integration of third-party modem

          Last year a difficult problem to solve is the high-end platform 1080p  lcd Occasional blue screen problems, but it usually happens once a week or even not. It took a long time to finally settle the pressure. Tim case to Qualcomm, they can not solve, the last is their own bite to solve, This problem is difficult to reproduce bug difficult Can solve the problem that cannot be solved by the manufacturers. Resolve post-Qualcomm support in turn ask how to solve? It's very moist. For Qualcomm support engineers I want to say that they support more and more slowly, many times entirely on their own, incredibly sometimes say no machine, but every time you close case

          From last year can give companies to solve some of the more difficult underlying issues to the current leadership of the LCD and other peripherals to the commissioning of new recruits, personal ability to slowly grow, and now still very concerned about linux kernel inside some of the drive and other research to solve some difficult problems. Not as proficient as the linux kernel But can be said to be very familiar with the product at the bottom of the problem can quickly locate the analysis. Personal feeling even if the driver for ten years is not proficient, after all, linux kerne linux The person who improved the system kernel.

        Some time ago saw others to do MTK drive, say how simple, The killed the young man, who was fortunate to have chosen to be a high-pass driver. Previously also can choose to do MTK driven or wince , as I know kernel code is really beautiful, Foreigners write high quality, at the same time the device driver is very rich, for the people who have just participated in the work is very useful, learned very much. For MTK I haven't done it, though People say how how, but the domestic run up after all is very good. Individuals feel that knowledge lies in deep research to be able to grow. There is a chance to contact a few more platforms later. But the feeling of Linux drive and platform relationship is not very big, after all linux The large frame was placed there.

I remember when I first entered the work is very impetuous, anxious to function on the OK. But now the work is more to enjoy, a kind of accumulation, a deep excavation process. Do products more is to focus on their own late trial to find out or test out the problem, while positioning to solve the problem.

Make Qualcomm platform Android Drive Testimonials