On Wed, Dec 19, 2018 at 10:31:35AM +0000, Patrice CHOTARD wrote: > Hi Russell > > On 12/18/18 6:27 PM, Russell King - ARM Linux wrote: > > On Tue, Dec 18, 2018 at 05:05:18PM +0000, Patrice CHOTARD wrote: > >> Hi Russell > >> > >> On 12/18/18 4:52 PM, Russell King - ARM Linux wrote: > >>> On Tue, Dec 18, 2018 at 03:48:13PM +0100, [email protected] wrote: > >>>> From: Patrice Chotard <[email protected]> > >>>> > >>>> Due to pen_release and boot_lock removal, secondary CPU's bringup > >>>> was broken. Restore CPU's bringup by reworking properly > >>>> .smp_prepare_cpus and .smp_boot_secondary STi callbacks. > >>> > >>> Sorry, maybe I don't understand your commit message, but you seem to be > >>> saying that removal of the pen_release and boot_lock broke STi's secondary > >>> CPU bring up? Please clarify, and explain how that happened. > >> > >> Correct, CPU1 failed to come online. > >> > >> It seems that writing secondary_startup address at cpu-release-addr in > >> .smp_prepare_cpus callback was too early. > >> > >> Doing it in .smp_boot_secondary callback, insures that secondary_data > >> struct is populated in __cpu_up() (stack, pgdir and swapper_pg_dir fields). > > > > Ah, you're saying that it causes the CPU to jump to secondary_startup > > while the boot CPU is in smp_prepare_cpus()? What triggers the CPU > > Yes > > > to jump to the address written to cpu_strt_ptr? What you're saying > > seems to suggest that it's the write to that address, rather than the > > IPI that's sent in sti_boot_secondary(). > > At platform startup, an U-Bootrom firmware initialize secondary CPU and > make it spinning waiting for a jump address to be written at cpu_strt_ptr. > > I didn't pay attention to the IPI, you are right IPI is useless, i will > remove it.
Okay, in that case may I suggest an alternative to taking my patch which will break this, and then fixing it in a subsequent patch - please merge the two patches together so it becomes one "clean up" patch which doesn't cause any breakage. Thanks. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up
