Hi, On 07/24/2012 06:02 AM, Jingoo Han wrote: >>>>>>>> I wonder fimd clock has any dependency with DP >>>>>>> FIMD pixel clock is necessary to enable DP. >>>>>> So then, i think DP driver also should control FIMD pixel clock. >>>>>> Do you have any patch or plan for it? >>>>> Um, I don't think so. >>>>> Because, DP cannot work by itself. >>>>> In order to use DP, FIMD should be enabled. >>>>> >>>>> If FIMD is enabled, FIMD pixel clock is enabled; >>>>> therefore, DP driver does not need to control FIMD pixel clock. >>>> Why does DP driver have FIMD driver dependency? Also for this, it needs >>>> FIMD driver is probed earlier then DP driver. We cannot decide driver >>>> probe order if they are same level drivers and itself is weird >>>> condition. Although there is hardware dependency, DP and FIMD driver >>>> don't have any code relations. They are each other drivers. But DP >>>> needs FIMD pixel clock and because the clock can be control at the >>>> several drivers and the clock framework exists for that, then i think >>>> it's better DP driver also control FIMD pixel clock. >>>> >>>>> In my opinion, adding config dependency would be better, such as FB_S3C or DRM_EXYNOS_FIMD. >>>> I think this is not solution. How do you ensure FIMD driver is probed >>>> earlier than DP driver? Even if it's possible, when FIMD driver only >>>> controls pixel clock, DP driver will execute any operations regardless >>>> status of FIMD pixel clock, so if FIMD driver turns off pixel clock, >>>> then DP will occur any error. >>> late_initcall can ensure DP driver is probed later. >> >> I'm not sure late_initcall solution is good. It must choose at the last >> if there isn't other way really. > > > late_initcall is already used by many drivers. > If you have any good idea, please, suggest it. I agree with Mr. Shim here. using initcall doesn't look like a solution to this issue. Neither compile time dependency is of much help. The S3C framebuffer driver can be used as a loadable module, how would initcalls be supposed to work then ? Some notify mechanisms or deferred probing could be used, to make sure one of drivers is initialized before the other. -- Thanks, Sylwester -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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