Messages in this thread | | | From | Måns Rullgård <> | Subject | Re: [PATCH v3 3/4] clk: sunxi-ng: Convert early providers to platform drivers | Date | Wed, 28 Jun 2023 19:33:35 +0100 |
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Maxime Ripard <mripard@kernel.org> writes:
> On Wed, Jun 28, 2023 at 12:07:56PM +0100, Måns Rullgård wrote: >> Maxime Ripard <mripard@kernel.org> writes: >> >> > On Mon, Jun 26, 2023 at 01:21:33PM +0100, Måns Rullgård wrote: >> >> Samuel Holland <samuel@sholland.org> writes: >> >> >> >> > The PRCM CCU drivers depend on clocks provided by other CCU drivers. For >> >> > example, the sun8i-r-ccu driver uses the "pll-periph" clock provided by >> >> > the SoC's main CCU. >> >> > >> >> > However, sun8i-r-ccu is an early OF clock provider, and many of the >> >> > main CCUs (e.g. sun50i-a64-ccu) use platform drivers. This means that >> >> > the consumer clocks will be orphaned until the supplier driver is bound. >> >> > This can be avoided by converting the remaining CCUs to use platform >> >> > drivers. Then fw_devlink will ensure the drivers are bound in the >> >> > optimal order. >> >> > >> >> > The sun5i CCU is the only one which actually needs to be an early clock >> >> > provider, because it provides the clock for the system timer. That one >> >> > is left alone. >> >> > >> >> > Signed-off-by: Samuel Holland <samuel@sholland.org> >> >> > --- >> >> > >> >> > (no changes since v1) >> >> > >> >> > drivers/clk/sunxi-ng/Kconfig | 20 ++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun4i-a10.c | 58 +++++++++++++-------- >> >> > drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c | 56 ++++++++++++-------- >> >> > drivers/clk/sunxi-ng/ccu-sun50i-h616.c | 33 ++++++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun6i-a31.c | 40 +++++++++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-a23.c | 35 +++++++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-a33.c | 40 +++++++++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-h3.c | 62 ++++++++++++++-------- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-r.c | 65 ++++++++++++++---------- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-v3s.c | 57 +++++++++++++-------- >> >> > drivers/clk/sunxi-ng/ccu-suniv-f1c100s.c | 38 ++++++++++---- >> >> > 11 files changed, 332 insertions(+), 172 deletions(-) >> >> >> >> This broke the hstimer clocksource on A20 since it requires a clock >> >> provided by the sun4i ccu driver. >> > >> > The A10 is probably broken by this, but the A20 should be able to use >> > the arch timers just like all the other Cortex-A7-based SoCs. >> > >> > Do you have a dmesg log that could help debug why it's not working? >> >> The A20 works as such since, as you say, it has other clocksources. >> However, the hstimer has become unusable. If anyone was using, for >> whatever reason, it won't be working for them now. >> >> Before this change, the kernel log used include this line: >> >> clocksource: hstimer: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 6370868154 ns >> >> Now there is only a cryptic "Can't get timer clock" in its place. >> >> As it is now, the hstimer driver is nothing but a waste of space. >> I figure it ought to be fixed one way or another. > > Yeah, definitely. > > IIRC, the situation is: > > - A10 has just the "regular", old, timer > - A10s/A13/GR8 has the A10 timer + hstimer > - A20 has the A13 timers + arch timers > > We also default to the hstimer only for the A10s/A13 which aren't > affected by this patch series afaics. > > We also enable the HS timer for the A31, but just like the A20 it > doesn't use it by default, so it's probably been broken there too. > > I guess one way to fix it would be to switch the HS timer driver to a > lower priority than the A10 timer, so we pick that up by default instead > for the A10s/A13, and then convert the HS timer driver to a proper > platform_device driver that will be able to get its clock. > > The downside is that the A13 will lose some precision over its default > timer, but I don't think it's a big deal.
The options I see are converting the hstimer to a platform device or reverting the change to the sun4i ccu driver.
I don't personally have much of an opinion on this since my systems aren't affected. The only reason I looked at it was that I noticed a new error message in the kernel logs.
-- Måns Rullgård
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