On 6.05.2023 22:10, Luca Weiss wrote:
> On older platforms like msm8226, msm8974 and msm8916 the driver in the
> downstream kernel enables scaling first before doing the handover of the
> clocks.
>
> While this normally doesn't seem to cause noticeable problems, on
> apq8026-asus-sparrow this causes the device to immediately reboot,
> perhaps due to older rpm firmware that becomes unhappy.
>
> On newer platforms the order has swapped and enabling scaling is done
> after the handover, so let's introduce this behavior only conditionally
> for msm8226 and msm8974 for now.
>
> Signed-off-by: Luca Weiss <luca@xxxxxxxxx>
> ---
Did you give this a spin on some 8974? I think hammerhead had
issues around rpmcc in the past..
Konrad
> drivers/clk/qcom/clk-smd-rpm.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/qcom/clk-smd-rpm.c b/drivers/clk/qcom/clk-smd-rpm.c
> index 887b945a6fb7..6d5476afc4d1 100644
> --- a/drivers/clk/qcom/clk-smd-rpm.c
> +++ b/drivers/clk/qcom/clk-smd-rpm.c
> @@ -178,6 +178,7 @@ struct clk_smd_rpm_req {
> struct rpm_smd_clk_desc {
> struct clk_smd_rpm **clks;
> size_t num_clks;
> + bool scaling_before_handover;
> };
>
> static DEFINE_MUTEX(rpm_smd_clk_lock);
> @@ -693,6 +694,7 @@ static struct clk_smd_rpm *msm8974_clks[] = {
> static const struct rpm_smd_clk_desc rpm_clk_msm8974 = {
> .clks = msm8974_clks,
> .num_clks = ARRAY_SIZE(msm8974_clks),
> + .scaling_before_handover = true,
> };
>
> static struct clk_smd_rpm *msm8976_clks[] = {
> @@ -1318,6 +1320,12 @@ static int rpm_smd_clk_probe(struct platform_device *pdev)
> rpm_smd_clks = desc->clks;
> num_clks = desc->num_clks;
>
> + if (desc->scaling_before_handover) {
> + ret = clk_smd_rpm_enable_scaling(rpm);
> + if (ret)
> + goto err;
> + }
> +
> for (i = 0; i < num_clks; i++) {
> if (!rpm_smd_clks[i])
> continue;
> @@ -1329,9 +1337,11 @@ static int rpm_smd_clk_probe(struct platform_device *pdev)
> goto err;
> }
>
> - ret = clk_smd_rpm_enable_scaling(rpm);
> - if (ret)
> - goto err;
> + if (!desc->scaling_before_handover) {
> + ret = clk_smd_rpm_enable_scaling(rpm);
> + if (ret)
> + goto err;
> + }
>
> for (i = 0; i < num_clks; i++) {
> if (!rpm_smd_clks[i])
>
> ---
> base-commit: dd9e11d6477a52ede9ebe575c83285e79e823889
> change-id: 20230506-rpmcc-scaling-handover-a63029ed9d13
>
> Best regards,
