[Freedreno] [PATCH v2 08/17] drm/msm/dpu: add changes to support writeback in hw_ctl

Dmitry Baryshkov dmitry.baryshkov at linaro.org
Wed Apr 20 18:48:24 UTC 2022


On Wed, 20 Apr 2022 at 20:16, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>
>
>
> On 4/19/2022 11:59 PM, Dmitry Baryshkov wrote:
> > On 20/04/2022 04:46, Abhinav Kumar wrote:
> >> Add changes to support writeback module in the dpu_hw_ctl
> >> interface.
> >>
> >> changes in v2:
> >>     - keep only the wb specific changes to reset_intf_cfg
> >>     - use cfg->intf / cfg->wb to identify intf or wb
> >>     - use bit-wise OR for the wb bits while programming
> >>
> >> Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
> >> ---
> >>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c | 43
> >> +++++++++++++++++++++++++++---
> >>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h | 15 ++++++++++-
> >>   2 files changed, 53 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> >> b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> >> index 524f024..495a9cd 100644
> >> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> >> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c
> >> @@ -1,5 +1,6 @@
> >>   // SPDX-License-Identifier: GPL-2.0-only
> >> -/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
> >> +/* Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights
> >> reserved.
> >> + * Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
> >>    */
> >>   #include <linux/delay.h>
> >> @@ -23,10 +24,12 @@
> >>   #define   CTL_SW_RESET                  0x030
> >>   #define   CTL_LAYER_EXTN_OFFSET         0x40
> >>   #define   CTL_MERGE_3D_ACTIVE           0x0E4
> >> +#define   CTL_WB_ACTIVE                 0x0EC
> >>   #define   CTL_INTF_ACTIVE               0x0F4
> >>   #define   CTL_MERGE_3D_FLUSH            0x100
> >>   #define   CTL_DSC_ACTIVE                0x0E8
> >>   #define   CTL_DSC_FLUSH                0x104
> >> +#define   CTL_WB_FLUSH                  0x108
> >>   #define   CTL_INTF_FLUSH                0x110
> >>   #define   CTL_INTF_MASTER               0x134
> >>   #define   CTL_FETCH_PIPE_ACTIVE         0x0FC
> >> @@ -38,6 +41,7 @@
> >>   #define  MERGE_3D_IDX   23
> >>   #define  DSC_IDX        22
> >>   #define  INTF_IDX       31
> >> +#define WB_IDX          16
> >>   #define CTL_INVALID_BIT                 0xffff
> >>   #define CTL_DEFAULT_GROUP_ID        0xf
> >> @@ -135,6 +139,9 @@ static inline void
> >> dpu_hw_ctl_trigger_flush_v1(struct dpu_hw_ctl *ctx)
> >>       if (ctx->pending_flush_mask & BIT(INTF_IDX))
> >>           DPU_REG_WRITE(&ctx->hw, CTL_INTF_FLUSH,
> >>                   ctx->pending_intf_flush_mask);
> >> +    if (ctx->pending_flush_mask & BIT(WB_IDX))
> >> +        DPU_REG_WRITE(&ctx->hw, CTL_WB_FLUSH,
> >> +                ctx->pending_wb_flush_mask);
> >>       DPU_REG_WRITE(&ctx->hw, CTL_FLUSH, ctx->pending_flush_mask);
> >>   }
> >> @@ -255,6 +262,13 @@ static void
> >> dpu_hw_ctl_update_pending_flush_intf(struct dpu_hw_ctl *ctx,
> >>       }
> >>   }
> >> +static void dpu_hw_ctl_update_pending_flush_wb_v1(struct dpu_hw_ctl
> >> *ctx,
> >> +        enum dpu_wb wb)
> >> +{
> >> +    ctx->pending_wb_flush_mask |= BIT(wb - WB_0);
> >> +    ctx->pending_flush_mask |= BIT(WB_IDX);
> >> +}
> >> +
> >>   static void dpu_hw_ctl_update_pending_flush_intf_v1(struct
> >> dpu_hw_ctl *ctx,
> >>           enum dpu_intf intf)
> >>   {
> >> @@ -504,6 +518,7 @@ static void dpu_hw_ctl_intf_cfg_v1(struct
> >> dpu_hw_ctl *ctx,
> >>   {
> >>       struct dpu_hw_blk_reg_map *c = &ctx->hw;
> >>       u32 intf_active = 0;
> >> +    u32 wb_active = 0;
> >>       u32 mode_sel = 0;
> >>       /* CTL_TOP[31:28] carries group_id to collate CTL paths
> >> @@ -519,11 +534,20 @@ static void dpu_hw_ctl_intf_cfg_v1(struct
> >> dpu_hw_ctl *ctx,
> >>       if (cfg->intf_mode_sel == DPU_CTL_MODE_SEL_CMD)
> >>           mode_sel |= BIT(17);
> >> -    intf_active = DPU_REG_READ(c, CTL_INTF_ACTIVE);
> >> -    intf_active |= BIT(cfg->intf - INTF_0);
> >> +    if (cfg->intf) {
> >> +        intf_active = DPU_REG_READ(c, CTL_INTF_ACTIVE);
> >> +        intf_active |= BIT(cfg->intf - INTF_0);
> >> +    }
> >> +
> >> +    if (cfg->wb) {
> >> +        wb_active = DPU_REG_READ(c, CTL_WB_ACTIVE);
> >> +        wb_active |= BIT(cfg->wb - WB_0);
> >> +    }
> >>       DPU_REG_WRITE(c, CTL_TOP, mode_sel);
> >>       DPU_REG_WRITE(c, CTL_INTF_ACTIVE, intf_active);
> >> +    DPU_REG_WRITE(c, CTL_WB_ACTIVE, wb_active);
> >
> > This will not work as expected. If cfg->intf is not set, CTL_INTF_ACTIVE
> > will be reset to 0 (while it should have been retained). Please change
> > this to always read CTL_INTF_ACTIVE/CTL_WB_ACTIVE.
>
> ack, and thanks for catching this.
> Yes, i need to add the always read part back.
>
> >
> >> +
> >>       if (cfg->merge_3d)
> >>           DPU_REG_WRITE(c, CTL_MERGE_3D_ACTIVE,
> >>                     BIT(cfg->merge_3d - MERGE_3D_0));
> >> @@ -546,6 +570,9 @@ static void dpu_hw_ctl_intf_cfg(struct dpu_hw_ctl
> >> *ctx,
> >>           intf_cfg |= (cfg->mode_3d - 0x1) << 20;
> >>       }
> >> +    if (cfg->wb)
> >> +        intf_cfg |= (cfg->wb & 0x3) + 2;
> >> +
> >
> > Ugh. I see that we have the same code in downstream driver. And that we
> > do not support WB_0 at all. But maybe we should be more explicit here.
>
> Sorry, I didnt follow this comment. Why is this related to WB_0?
>
> All this code is doing is that its programming the lower bits of CTL_TOP
> register to be used for WB mode.
>
> The correct value of this register for linear wb mode which we use is 0x5.
>
> Which will still be correct now because cfg->wb will be 0x3.
>
> Coming to other non-WB_2 values, this code is still correct.
>
> Lets say cfg->wb was 0x1 ( for WB_0), then the register will be
> programmed to 0x3 which is the correct value to use because then we will
> be using rotation and not linear writeback.
>
> Perhaps, you need a comment here to explain this?

IIRC, at least for 8916 WB_0 must be used with this field set to 0x1
or 0x3 depending on other settings.
Thus I thought it might be better to be explicit here.

As a second thought, let's keep it as is (and if somebody works on
WB_0/rotation support, he will know what to set here anyway).

>
> >
> >>       switch (cfg->intf_mode_sel) {
> >>       case DPU_CTL_MODE_SEL_VID:
> >>           intf_cfg &= ~BIT(17);
> >> @@ -568,12 +595,13 @@ static void dpu_hw_ctl_reset_intf_cfg_v1(struct
> >> dpu_hw_ctl *ctx,
> >>   {
> >>       struct dpu_hw_blk_reg_map *c = &ctx->hw;
> >>       u32 intf_active = 0;
> >> +    u32 wb_active = 0;
> >>       u32 merge3d_active = 0;
> >>       /*
> >>        * This API resets each portion of the CTL path namely,
> >>        * clearing the sspps staged on the lm, merge_3d block,
> >> -     * interfaces etc to ensure clean teardown of the pipeline.
> >> +     * interfaces , writeback etc to ensure clean teardown of the
> >> pipeline.
> >>        * This will be used for writeback to begin with to have a
> >>        * proper teardown of the writeback session but upon further
> >>        * validation, this can be extended to all interfaces.
> >> @@ -592,6 +620,12 @@ static void dpu_hw_ctl_reset_intf_cfg_v1(struct
> >> dpu_hw_ctl *ctx,
> >>           intf_active &= ~BIT(cfg->intf - INTF_0);
> >>           DPU_REG_WRITE(c, CTL_INTF_ACTIVE, intf_active);
> >>       }
> >> +
> >> +    if (cfg->wb) {
> >> +        wb_active = DPU_REG_READ(c, CTL_WB_ACTIVE);
> >> +        wb_active &= ~BIT(cfg->wb - WB_0);
> >> +        DPU_REG_WRITE(c, CTL_WB_ACTIVE, wb_active);
> >> +    }
> >>   }
> >>   static void dpu_hw_ctl_set_fetch_pipe_active(struct dpu_hw_ctl *ctx,
> >> @@ -622,6 +656,7 @@ static void _setup_ctl_ops(struct dpu_hw_ctl_ops
> >> *ops,
> >>               dpu_hw_ctl_update_pending_flush_intf_v1;
> >>           ops->update_pending_flush_merge_3d =
> >>               dpu_hw_ctl_update_pending_flush_merge_3d_v1;
> >> +        ops->update_pending_flush_wb =
> >> dpu_hw_ctl_update_pending_flush_wb_v1;
> >
> > Do we also need the update_pending_flush_wb for non-ACTIVE_CTL case? I
> > think we do.
>
> Yes, but the bits will be different. I can update it.

Yes, please.

>
> >
> >>       } else {
> >>           ops->trigger_flush = dpu_hw_ctl_trigger_flush;
> >>           ops->setup_intf_cfg = dpu_hw_ctl_intf_cfg;
> >> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> >> b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> >> index c61a8fd..df8f8e9 100644
> >> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> >> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h
> >> @@ -1,5 +1,6 @@
> >>   /* SPDX-License-Identifier: GPL-2.0-only */
> >> -/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
> >> +/* Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights
> >> reserved.
> >> + * Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
> >>    */
> >>   #ifndef _DPU_HW_CTL_H
> >> @@ -44,6 +45,7 @@ struct dpu_hw_stage_cfg {
> >>    */
> >>   struct dpu_hw_intf_cfg {
> >>       enum dpu_intf intf;
> >> +    enum dpu_wb wb;
> >>       enum dpu_3d_blend_mode mode_3d;
> >>       enum dpu_merge_3d merge_3d;
> >>       enum dpu_ctl_mode_sel intf_mode_sel;
> >> @@ -102,6 +104,15 @@ struct dpu_hw_ctl_ops {
> >>           u32 flushbits);
> >>       /**
> >> +     * OR in the given flushbits to the cached pending_(wb_)flush_mask
> >> +     * No effect on hardware
> >> +     * @ctx       : ctl path ctx pointer
> >> +     * @blk       : writeback block index
> >> +     */
> >> +    void (*update_pending_flush_wb)(struct dpu_hw_ctl *ctx,
> >> +        enum dpu_wb blk);
> >> +
> >> +    /**
> >>        * OR in the given flushbits to the cached
> >> pending_(intf_)flush_mask
> >>        * No effect on hardware
> >>        * @ctx       : ctl path ctx pointer
> >> @@ -199,6 +210,7 @@ struct dpu_hw_ctl_ops {
> >>    * @mixer_hw_caps: mixer hardware capabilities
> >>    * @pending_flush_mask: storage for pending ctl_flush managed via ops
> >>    * @pending_intf_flush_mask: pending INTF flush
> >> + * @pending_wb_flush_mask: pending WB flush
> >>    * @ops: operation list
> >>    */
> >>   struct dpu_hw_ctl {
> >> @@ -212,6 +224,7 @@ struct dpu_hw_ctl {
> >>       const struct dpu_lm_cfg *mixer_hw_caps;
> >>       u32 pending_flush_mask;
> >>       u32 pending_intf_flush_mask;
> >> +    u32 pending_wb_flush_mask;
> >>       u32 pending_merge_3d_flush_mask;
> >>       /* ops */
> >
> >



-- 
With best wishes
Dmitry


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