Hi Christian, Gregory,
> From: Christian Neubert <christian.neubert.86@xxxxxxxxx>
>
> The clock parenting was not setup properly when DVFS was enabled. It was
> expected that the same clock source was used with and without DVFS which
> was not the case.
>
> This patch fixes this issue, allowing to make the cpufreq support work
> when the CPU clock source are not the default ones.
>
> Fixes: 92ce45fb875d ("cpufreq: Add DVFS support for Armada 37xx")
> Cc: <stable@xxxxxxxxxxxxxxx>
> [gregory: extract from a larger patch, modify comments and commit log]
> Signed-off-by: Christian Neubert <christian.neubert.86@xxxxxxxxx>
> Signed-off-by: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
> ---
> drivers/cpufreq/armada-37xx-cpufreq.c | 20 +++++++++++++++++---
> 1 file changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/cpufreq/armada-37xx-cpufreq.c b/drivers/cpufreq/armada-37xx-cpufreq.c
> index 75491fc841a6..ad4463e4266e 100644
> --- a/drivers/cpufreq/armada-37xx-cpufreq.c
> +++ b/drivers/cpufreq/armada-37xx-cpufreq.c
> @@ -162,11 +162,25 @@ static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base,
> }
>
> /*
> - * Set cpu clock source, for all the level we keep the same
> - * clock source that the one already configured. For this one
> - * we need to use the clock framework
> + * Set CPU clock source, for all the level we keep the same
> + * clock source that the one already configured with DVS
> + * disabled. For this one we need to use the clock framework
> */
> parent = clk_get_parent(clk);
> +
> + /*
> + * Unset parent clock to force the clock framework setting again
> + * the clock parent
> + */
> + clk_set_parent(clk, NULL);
> +
> + /*
> + * For the Armada 37xx CPU clocks, setting the parent will
> + * actually configure the parent when DVFS is enabled. At
> + * hardware level it will be a different register from the one
> + * read when doing clk_get_parent that will be set with
> + * clk_set_parent.
> + */
> clk_set_parent(clk, parent);
> }
>
> --
> 2.20.1
>
I applied this and selected only
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_POWERSAVE=y
The board boots up with 'powersave' instead of 'performance' (maybe some init
script?)
When i tried changing to 'performance' i got this:
[ 164.134589] Internal error: synchronous parity or ECC error: 96000018 [#1]
PREEMPT SMP
[ 164.139899] Modules linked in: mvneta mvmdio phylink crct10dif_ce ip_tables
x_tables ipv6
[ 164.148321] CPU: 1 PID: 2485 Comm: bash Not tainted 5.0.0espressobin+ #68
[ 164.155305] Hardware name: Globalscale Marvell ESPRESSOBin Board (DT)
[ 164.161938] pstate: 000003c5 (nzcv DAIF -PAN -UAO)
[ 164.166873] pc : do_mem_abort+0x48/0xb0
[ 164.170808] lr : el1_da+0x20/0x88
[ 164.174210] sp : ffff000011b5b1f0
[ 164.177614] x29: ffff000011b5b1f0 x28: ffff80003a0ab800
[ 164.183080] x27: 0000000000000000 x26: 0000000000000000
[ 164.188545] x25: 0000000000000000 x24: 0000000000000025
[ 164.194012] x23: 00000000000003c5 x22: ffff000010c37318
[ 164.199477] x21: ffff000010c371f0 x20: ffff000011b5b220
[ 164.204942] x19: 000000009600004f x18: 0000000000000000
[ 164.210408] x17: 0000000000000000 x16: 0000000000000005
[ 164.215873] x15: 0000000000000000 x14: 0000000000000000
[ 164.221339] x13: ffff80003ac55168 x12: ffff80003ac55168
[ 164.226805] x11: 0000000000000026 x10: 0101010101010101
[ 164.232270] x9 : 0000000000000000 x8 : 0000000000000000
[ 164.237735] x7 : 0000000000000000 x6 : 0000000000000000
[ 164.243201] x5 : 0000000000000000 x4 : 0000000000000000
[ 164.248667] x3 : 0000000000000000 x2 : 0000000000000000
[ 164.254133] x1 : 0000000000000000 x0 : 0000000000000000
[ 164.259601] Process bash (pid: 2485, stack limit = 0x00000000eb09c765)
[ 164.266318] Call trace:
[ 164.268830] do_mem_abort+0x48/0xb0
[ 164.272413] el1_da+0x20/0x88
[ 164.275460] el1_error+0x14/0xe4
[ 164.278778] Code: 2a1303e1 9ba07c63 aa1603e0 8b030095 (f8636883)
[ 164.285053] ---[ end trace 78a878c96fcb4581 ]---
[ 164.289795] Kernel panic - not syncing: Fatal exception
[ 164.295171] SMP: stopping secondary CPUs
[ 164.299211] Kernel Offset: disabled
[ 164.302788] CPU features: 0x002,2000200c
[ 164.306817] Memory Limit: none
[ 164.309961] ---[ end Kernel panic - not syncing: Fatal exception ]---
Cheers
/Ilias
