Messages in this thread | | | Date | Wed, 17 May 2023 03:09:19 +0300 | Subject | Re: [PATCH V6 2/3] soc: qcom: boot_stat: Add Driver Support for Boot Stats | From | Dmitry Baryshkov <> |
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On 16/05/2023 11:19, Arnd Bergmann wrote: > On Tue, May 9, 2023, at 12:52, Souradeep Chowdhury wrote: >> All of Qualcomm's proprietary Android boot-loaders capture boot time >> stats, like the time when the bootloader started execution and at what >> point the bootloader handed over control to the kernel etc. in the IMEM >> region. This information is captured in a specific format by this driver >> by mapping a structure to the IMEM memory region and then accessing the >> members of the structure to show the information within debugfs file. >> This information is useful in verifying if the existing boot KPIs have >> regressed or not. The information is shown in milliseconds, a sample >> log from sm8450(waipio) device is as follows:- >> >> /sys/kernel/debug/qcom_boot_stats # cat abl_time >> 17898 ms >> /sys/kernel/debug/qcom_boot_stats # cat pre_abl_time >> 2879 ms >> >> The Module Power Manager(MPM) sleep counter starts ticking at the PBL >> stage and the timestamp generated by the sleep counter is logged by >> the Qualcomm proprietary bootloader(ABL) at two points-> First when it >> starts execution which is logged here as "pre_abl_time" and the second >> when it is about to load the kernel logged as "abl_time". Documentation >> details are also added in Documentation/ABI/testing/debugfs-driver-bootstat >> >> Signed-off-by: Souradeep Chowdhury <quic_schowdhu@quicinc.com> >> --- >> .../ABI/testing/debugfs-driver-bootstat | 17 +++ >> drivers/soc/qcom/Kconfig | 10 ++ >> drivers/soc/qcom/Makefile | 1 + >> drivers/soc/qcom/boot_stats.c | 100 ++++++++++++++++++ > > As mentioned in my reply to the binding, I don't think this should > be a driver at all. On top of that, even if it was a driver, it is > clearly not a "soc" driver since nothing in it has any relevance to > the hardware, rather than the first-stage loader, and drivers/soc/ > drivers should never have their own user space interface either.
I suppose that we should add a proper driver for imem rather than always using it through syscon.
-- With best wishes Dmitry
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