On 07/04/2016 01:03 PM, Alim Akhtar wrote: > As per code flow it is possible that s3c_rtc_setfreq() might get called > with rtc clock disabled and in set_freq we perform h/w registers read/write, > which might results in a kernel crash while probing rtc driver. > Below is one such case: > s3c_rtc_probe() > clk_prepare_enable(info->rtc_clk) // rtc clock enabled > s3c_rtc_gettime() // will enable clk if not done, and disable it upon > exit > s3c_rtc_setfreq() //then this will be called with clk disabled
The indentation suggests levels of calls (chain) not sequence. This should be: s3c_rtc_probe() clk_prepare_enable(info->rtc_clk) // rtc clock enabled s3c_rtc_gettime() // will enable clk if not done, and disable it upon exit s3c_rtc_setfreq() //then this will be called with clk disabled > > This patch take cares of such issue by adding s3c_rtc_{enable/disable}_clk in > s3c_rtc_setfreq(). What I don't get is that you wrote "it is *possible* that s3c_rtc_setfreq() *might* get called". From my understanding this will happen always because src_rtc_gettime() always disables the clocks. Why it does not happen always? Best regards, Krzysztof -- You received this message because you are subscribed to "rtc-linux". Membership options at http://groups.google.com/group/rtc-linux . Please read http://groups.google.com/group/rtc-linux/web/checklist before submitting a driver. --- You received this message because you are subscribed to the Google Groups "rtc-linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to rtc-linux+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.