On Mon, 6 Mar 2023 at 08:35, Krzysztof Kozlowski
<krzysztof.kozlowski@xxxxxxxxxx> wrote:
>
> On 23/02/2023 05:19, Sam Protsenko wrote:
> > Extract parent clock enabling from exynos_arm64_register_cmu() to
> > dedicated function.
> >
> > Acked-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> > Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> > Signed-off-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>
> > ---
> > Changes in v3:
> > - Rebased on top of latest soc/for-next tree
> > - Added Marek's Acked-by tag
> >
> > Changes in v2:
> > - Rebased on top of latest soc/for-next tree
> > - Improved English in kernel doc comment
> > - Added clk_prepare_enable() return value check
> > - Added exynos_arm64_enable_bus_clk() check in
> > exynos_arm64_register_cmu()
> > - Changed the commit message to reflect code changes
> >
> > drivers/clk/samsung/clk-exynos-arm64.c | 51 ++++++++++++++++++--------
> > 1 file changed, 35 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/clk/samsung/clk-exynos-arm64.c b/drivers/clk/samsung/clk-exynos-arm64.c
> > index b921b9a1134a..2aa3f0a5644e 100644
> > --- a/drivers/clk/samsung/clk-exynos-arm64.c
> > +++ b/drivers/clk/samsung/clk-exynos-arm64.c
> > @@ -56,6 +56,37 @@ static void __init exynos_arm64_init_clocks(struct device_node *np,
> > iounmap(reg_base);
> > }
> >
> > +/**
> > + * exynos_arm64_enable_bus_clk - Enable parent clock of specified CMU
> > + *
> > + * @dev: Device object; may be NULL if this function is not being
> > + * called from platform driver probe function
> > + * @np: CMU device tree node
> > + * @cmu: CMU data
> > + *
> > + * Keep CMU parent clock running (needed for CMU registers access).
> > + *
> > + * Return: 0 on success or a negative error code on failure.
> > + */
> > +static int __init exynos_arm64_enable_bus_clk(struct device *dev,
> > + struct device_node *np, const struct samsung_cmu_info *cmu)
> > +{
> > + struct clk *parent_clk;
> > +
> > + if (!cmu->clk_name)
> > + return 0;
> > +
> > + if (dev)
> > + parent_clk = clk_get(dev, cmu->clk_name);
> > + else
> > + parent_clk = of_clk_get_by_name(np, cmu->clk_name);
> > +
> > + if (IS_ERR(parent_clk))
> > + return PTR_ERR(parent_clk);
> > +
> > + return clk_prepare_enable(parent_clk);
> > +}
> > +
> > /**
> > * exynos_arm64_register_cmu - Register specified Exynos CMU domain
> > * @dev: Device object; may be NULL if this function is not being
> > @@ -72,23 +103,11 @@ static void __init exynos_arm64_init_clocks(struct device_node *np,
> > void __init exynos_arm64_register_cmu(struct device *dev,
> > struct device_node *np, const struct samsung_cmu_info *cmu)
> > {
> > - /* Keep CMU parent clock running (needed for CMU registers access) */
> > - if (cmu->clk_name) {
> > - struct clk *parent_clk;
> > -
> > - if (dev)
> > - parent_clk = clk_get(dev, cmu->clk_name);
> > - else
> > - parent_clk = of_clk_get_by_name(np, cmu->clk_name);
> > -
> > - if (IS_ERR(parent_clk)) {
> > - pr_err("%s: could not find bus clock %s; err = %ld\n",
> > - __func__, cmu->clk_name, PTR_ERR(parent_clk));
> > - } else {
> > - clk_prepare_enable(parent_clk);
> > - }
> > - }
> > + int err;
> >
> > + err = exynos_arm64_enable_bus_clk(dev, np, cmu);
> > + if (err)
> > + panic("%s: could not enable bus clock\n", __func__);
>
> The error handling is changed and not equivalent. I would say that we
> could still try to boot even if this failed, so kernel should not panic.
> Maybe the parent clock is enabled by bootloader.
>
Agreed, I've probably overlooked that one when making all the
refactoring. The same stands for the patch #6. Will rework and send
out those two separately soon, as the rest of patches you already
applied.
Thanks!
> Best regards,
> Krzysztof
>
