Re: [PATCH] clk: mvebu: armada-37xx-periph: Fix initialization for cpu clocks

Ilias Apalodimas
2019-03-18T11:28:51Z

Hi Gregory,
> Hi Ilias,
>
> On jeu., mars 14 2019, Ilias Apalodimas <ilias.apalodimas@linaro.org> wrote:
>
> > Hello Christian,
> >> Hi,
> >>
> >> I assume you use the 1000 MHz firmware. This does also not work on my Rev 7
> >> board. But I'm pretty sure this is not a problem of the patches, because if
> >> I take a newer kernel (4.19.20/27) without the patches it also does not
> >> work. A kernel 4.19.17 does work for me. My opinion on that is that this is
> >> another problem which does just occure now because now the cpu frequency
> >> scaling is working with the right frequencies.
> > I am not sure which firmware i am running, i did all my tests on 5.0.0 and
> > changing between governors worked fine without the patches
>
> Curently my espressobin is broken so I tested the patches on the Armada
> 3700 DB and I didn't observe the issue you had.
>
> The 3700 DB I used is configured to run at 800MHz.
>
> Could you apply the following patch and sent me the boot log?
>
> diff --git a/drivers/clk/mvebu/armada-37xx-periph.c b/drivers/clk/mvebu/armada-37xx-periph.c
> index 26ed3c18a239..f814ade5cd80 100644
> --- a/drivers/clk/mvebu/armada-37xx-periph.c
> +++ b/drivers/clk/mvebu/armada-37xx-periph.c
> @@ -452,14 +452,17 @@ static int clk_pm_cpu_set_parent(struct clk_hw *hw, u8 index)
>
> /* Set the parent clock for all the load level */
> for (load_level = 0; load_level < LOAD_LEVEL_NR; load_level++) {
> - unsigned int reg, mask, val,
> + unsigned int reg, mask, val, old,
> offset = ARMADA_37XX_NB_TBG_SEL_OFF;
>
> armada_3700_pm_dvfs_update_regs(load_level, &reg, &offset);
>
> val = index << offset;
> mask = ARMADA_37XX_NB_TBG_SEL_MASK << offset;
> + regmap_read(base, reg, &old);
> regmap_update_bits(base, reg, mask, val);
> + pr_err("%s old=%X -> val=0x%X load_level=%d\n",
> + __func__, old, val, load_level);
> }
> return 0;
> }
>
>
>
[ 14.909524] clk_pm_cpu_set_parent old=28004840 -> val=0x6000000 load_level=0
[ 14.916424] clk_pm_cpu_set_parent old=2E004840 -> val=0x600 load_level=1
[ 14.923315] clk_pm_cpu_set_parent old=8880A8C0 -> val=0x6000000 load_level=2
[ 14.930572] clk_pm_cpu_set_parent old=8E80A8C0 -> val=0x600 load_level=3

Let me know if you need anything else

Regards
/Ilias