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

[Dmitry Baryshkov]

On 01/06/2023 12:59, Konrad Dybcio wrote:
> On 1.06.2023 11:56, Dmitry Baryshkov wrote:
> > 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.
> Let's try to get more insight how they're correlated, but that sounds
> like an option.. 8996 will need this as well..

Anyway, I think this commit should be moved closer to the actual use.

> Konrad
> > > 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