This is a continuation of patch #2 ("clk: divider: Switch from
.round_rate to .determine_rate by default", [0]) from my other series:
"clk: meson: rounding for fast clocks on 32-bit SoCs" [1]
That patch caused NULL dereferences in various drivers which are still
accessing clk_divider_ops.round_rate directly (which got removed in the
mentioned patch).
Guenter Roeck found this issue first on Freescale i.MX6 Ultralite and
reported it here: [2]
Later on Marek Szyprowski reported that BCM2835 is also affected: [3]
With this improved version of the patch I am taking a more definsive
approach as suggested by Stephen Boyd. Instead of dropping
clk_divider_ops.round_rate we're now keeping it and adding
clk_divider_ops.determine_rate. CCF core already prefers
.determine_rate over .round_rate so the new implementation is used by
default.
To simplify the transition to .determine_rate in the future this
updated series now has five extra patches to port over the drivers
which used clk_divider_ops.round_rate over to
clk_divider_ops.determine_rate.
I have compile-tested all patches. Additionally the imx patch is
runtime-tested using Guenter Roeck's suggestion (thanks!):
$ qemu-system-arm -M mcimx6ul-evk -m 512M -kernel arch/arm/boot/zImage -dtb arch/arm/boot/dts/imx6ul-14x14-evk.dtb -append "console=ttymxc0 loglevel=8 earlycon earlyprintk" -monitor stdio
This series is based on clk-next commit 783d08bd02f5d3 ("Revert "clk:
divider: Switch from .round_rate to .determine_rate by default"clk-next").
My suggestion is to let all patches go through clk-next (instead of
individual driver trees) as the first patch in this series is a pre-
condition for the other ones.
[0] https://patchwork.kernel.org/project/linux-clk/patch/[email protected]/
[1] https://patchwork.kernel.org/project/linux-clk/cover/[email protected]/
[2] https://lore.kernel.org/linux-clk/[email protected]/
[3] https://lore.kernel.org/linux-clk/[email protected]/
Martin Blumenstingl (6):
clk: divider: Implement and wire up .determine_rate by default
clk: imx: clk-divider-gate: Switch to clk_divider.determine_rate
clk: bcm2835: Switch to clk_divider.determine_rate
clk: stm32f4: Switch to clk_divider.determine_rate
clk: stm32h7: Switch to clk_divider.determine_rate
clk: stm32mp1: Switch to clk_divider.determine_rate
drivers/clk/bcm/clk-bcm2835.c | 9 ++++-----
drivers/clk/clk-divider.c | 23 +++++++++++++++++++++++
drivers/clk/clk-stm32f4.c | 8 ++++----
drivers/clk/clk-stm32h7.c | 8 ++++----
drivers/clk/clk-stm32mp1.c | 10 +++-------
drivers/clk/imx/clk-divider-gate.c | 10 +++++-----
6 files changed, 43 insertions(+), 25 deletions(-)
--
2.32.0
Hi Stephen,
On Sat, Jul 3, 2021 at 12:51 AM Martin Blumenstingl
<[email protected]> wrote:
[...]
> Martin Blumenstingl (6):
> clk: divider: Implement and wire up .determine_rate by default
> clk: imx: clk-divider-gate: Switch to clk_divider.determine_rate
Abel has already picked this patch (thanks!)
Can you please take the rest of the series (that is: patch 1 and patches 3-6)?
I can also re-send them if you prefer that.
Best regards,
Martin
Quoting Martin Blumenstingl (2021-08-03 12:32:41)
> Hi Stephen,
>
>
> On Sat, Jul 3, 2021 at 12:51 AM Martin Blumenstingl
> <[email protected]> wrote:
> [...]
> > Martin Blumenstingl (6):
> > clk: divider: Implement and wire up .determine_rate by default
> > clk: imx: clk-divider-gate: Switch to clk_divider.determine_rate
> Abel has already picked this patch (thanks!)
>
> Can you please take the rest of the series (that is: patch 1 and patches 3-6)?
> I can also re-send them if you prefer that.
>
No need to resend. I can pick them up.