Messages in this thread | | | Date | Fri, 17 Apr 2020 13:18:02 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH AUTOSEL 5.4 095/108] ARM: shmobile: Enable ARM_GLOBAL_TIMER on Cortex-A9 MPCore SoCs |
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On Sun, Apr 12, 2020 at 10:44:01AM +0200, Geert Uytterhoeven wrote: >Hi Sasha, > >On Sun, Apr 12, 2020 at 1:11 AM Sasha Levin <sashal@kernel.org> wrote: >> From: Geert Uytterhoeven <geert+renesas@glider.be> >> >> [ Upstream commit 408324a3c5383716939eea8096a0f999a0665f7e ] >> >> SH-Mobile AG5 and R-Car H1 SoCs are based on the Cortex-A9 MPCore, which >> includes a global timer. >> >> Enable the ARM global timer on these SoCs, which will be used for: >> - the scheduler clock, improving scheduler accuracy from 10 ms to 3 or >> 4 ns, >> - delay loops, allowing removal of calls to shmobile_init_delay() from >> the corresponding machine vectors. >> >> Note that when using an old DTB lacking the global timer, the kernel >> will still work. However, loops-per-jiffies will no longer be preset, >> and the delay loop will need to be calibrated during boot. > >I.e. to avoid this delay, this patch is best backported after backporting >8443ffd1bbd5be74 ("ARM: dts: r8a7779: Add device node for ARM global timer"), >df1a0aac0a533e6f ("ARM: dts: sh73a0: Add device node for ARM global timer"). > >While the former has been backported to v5.[45]-stable, the latter hasn't, >probably because it depends on >61b58e3f6e518c51 ("ARM: dts: sh73a0: Rename twd clock to periph clock") > >So please backport the last two commits first.
Done, thanks!
-- Thanks, Sasha
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