On Fri, Jun 09, 2023 at 10:19:09PM +0200, Konrad Dybcio wrote:
> Before we issue a call to RPM through clk_smd_rpm_enable_scaling() the
> clock rate requests will not be commited in hardware. This poses a
> race threat since we're accessing the bus clocks directly from within
> the interconnect framework.
>
> Add a marker to indicate that we're good to go with sending new requests
> and export it so that it can be referenced from icc.
>
> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> ---
> drivers/clk/qcom/clk-smd-rpm.c | 9 +++++++++
> include/linux/soc/qcom/smd-rpm.h | 2 ++
> 2 files changed, 11 insertions(+)
>
> diff --git a/drivers/clk/qcom/clk-smd-rpm.c b/drivers/clk/qcom/clk-smd-rpm.c
> index 937cb1515968..482fe30ee6f0 100644
> --- a/drivers/clk/qcom/clk-smd-rpm.c
> +++ b/drivers/clk/qcom/clk-smd-rpm.c
> @@ -151,6 +151,7 @@
> #define to_clk_smd_rpm(_hw) container_of(_hw, struct clk_smd_rpm, hw)
>
> static struct qcom_smd_rpm *rpmcc_smd_rpm;
> +static bool smd_rpm_clk_scaling;
>
> struct clk_smd_rpm {
> const int rpm_res_type;
> @@ -385,6 +386,12 @@ static unsigned long clk_smd_rpm_recalc_rate(struct clk_hw *hw,
> return r->rate;
> }
>
> +bool qcom_smd_rpm_scaling_available(void)
> +{
> + return smd_rpm_clk_scaling;
> +}
> +EXPORT_SYMBOL_GPL(qcom_smd_rpm_scaling_available);
> +
> static int clk_smd_rpm_enable_scaling(void)
> {
> int ret;
> @@ -410,6 +417,8 @@ static int clk_smd_rpm_enable_scaling(void)
> return ret;
> }
>
> + smd_rpm_clk_scaling = true;
> +
If you move the platform_device_register_data(&rpdev->dev,
"icc_smd_rpm", ...) from drivers/soc/qcom/smd-rpm.c to here you can
avoid the race completely and drop this API. I think that would be
cleaner. And it will likely probe much faster because probe deferral
is slow. :)
Thanks,
Stephan
