Re: [PATCH 06/20] interconnect: qcom: icc-rpm: Allow negative QoS offset

[Dmitry Baryshkov]

On 30/05/2023 13:20, Konrad Dybcio wrote:
> In some very very very very unfortunate cases, the correct offset of
> the QoS registers will be.. negative. One such case is MSM8998, where
> The DDR BWMON occupies what-would-be-the-BIMC-base which we usually
> take into account with the register calculation, making the actual
> BIMC node start at what-would-be-the-BIMC-base+0x300.

Can we turn one of devices into a child of another device? This way we 
won't have to cope with negative offsets.

> In order to keep the calculation code sane, the simplest - however
> ugly it may be - solution is to allow the offset to be negative.
>
> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> ---
>   drivers/interconnect/qcom/icc-rpm.h | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/interconnect/qcom/icc-rpm.h b/drivers/interconnect/qcom/icc-rpm.h
> index d2c04c400cad..ba840a436cc0 100644
> --- a/drivers/interconnect/qcom/icc-rpm.h
> +++ b/drivers/interconnect/qcom/icc-rpm.h
> @@ -29,10 +29,10 @@ enum qcom_icc_type {
>    * @num_intf_clks: the total number of intf_clks clk_bulk_data entries
>    * @type: the ICC provider type
>    * @regmap: regmap for QoS registers read/write access
> - * @qos_offset: offset to QoS registers
>    * @bus_clk_rate: bus clock rate in Hz
>    * @bus_clks: the clk_bulk_data table of bus clocks
>    * @intf_clks: a clk_bulk_data array of interface clocks
> + * @qos_offset: offset to QoS registers

This can be kept in place.

>    * @keep_alive: whether to always keep a minimum vote on the bus clocks
>    * @is_on: whether the bus is powered on
>    */
> @@ -42,7 +42,7 @@ struct qcom_icc_provider {
>   	int num_intf_clks;
>   	enum qcom_icc_type type;
>   	struct regmap *regmap;
> -	unsigned int qos_offset;
> +	int qos_offset;
>   	u64 bus_clk_rate[NUM_BUS_CLKS];
>   	struct clk_bulk_data bus_clks[NUM_BUS_CLKS];
>   	struct clk_bulk_data *intf_clks;
> @@ -108,7 +108,7 @@ struct qcom_icc_desc {
>   	bool no_clk_scaling;
>   	enum qcom_icc_type type;
>   	const struct regmap_config *regmap_cfg;
> -	unsigned int qos_offset;
> +	int qos_offset;
>   };
>   
>   /* Valid for all bus types */

--
With best wishes
Dmitry