Re: [RFC PATCH 2/2] drm/msm/dsi: use new dpu_dsc_populate_dsc_config()

[Abhinav Kumar]

On 2/24/2023 1:04 PM, Dmitry Baryshkov wrote:
> On 24/02/2023 21:40, Kuogee Hsieh wrote:
> > use new introduced dpu_dsc_populate_dsc_config() to calculate
> > and populate drm_dsc_info instead of hard code value.
>
> DPU is an optional component, so DSI driver should not depend on the DPU 
> driver.

Today, the implicit dependency is already there. Without the DPU DSC 
blocks, the DSI cannot operate in compressed mode.

But, from a SW standpoint I agree we can separate this.

We can move this one level up to the disp/ or msm/ folder

What do you think about that?

> > Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/msm/dsi/dsi_host.c | 78 
> > ++++++--------------------------------
> >   1 file changed, 12 insertions(+), 66 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c 
> > b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > index 31ad193..5f3f84f 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > @@ -1,6 +1,7 @@
> >   // SPDX-License-Identifier: GPL-2.0-only
> >   /*
> >    * Copyright (c) 2015, The Linux Foundation. All rights reserved.
> > + * Copyright (c) 2023. Qualcomm Innovation Center, Inc. All rights 
> > reserved
> >    */
> >   #include <linux/clk.h>
> > @@ -21,7 +22,6 @@
> >   #include <video/mipi_display.h>
> > -#include <drm/display/drm_dsc_helper.h>
> >   #include <drm/drm_of.h>
> >   #include "dsi.h"
> > @@ -31,6 +31,7 @@
> >   #include "msm_kms.h"
> >   #include "msm_gem.h"
> >   #include "phy/dsi_phy.h"
> > +#include "dpu_dsc_helper.h"
> >   #define DSI_RESET_TOGGLE_DELAY_MS 20
> > @@ -1819,29 +1820,8 @@ static int dsi_host_parse_lane_data(struct 
> > msm_dsi_host *msm_host,
> >       return -EINVAL;
> >   }
> > -static u32 dsi_dsc_rc_buf_thresh[DSC_NUM_BUF_RANGES - 1] = {
> > -    0x0e, 0x1c, 0x2a, 0x38, 0x46, 0x54, 0x62,
> > -    0x69, 0x70, 0x77, 0x79, 0x7b, 0x7d, 0x7e
> > -};
> > -
> > -/* only 8bpc, 8bpp added */
> > -static char min_qp[DSC_NUM_BUF_RANGES] = {
> > -    0, 0, 1, 1, 3, 3, 3, 3, 3, 3, 5, 5, 5, 7, 13
> > -};
> > -
> > -static char max_qp[DSC_NUM_BUF_RANGES] = {
> > -    4, 4, 5, 6, 7, 7, 7, 8, 9, 10, 11, 12, 13, 13, 15
> > -};
> > -
> > -static char bpg_offset[DSC_NUM_BUF_RANGES] = {
> > -    2, 0, 0, -2, -4, -6, -8, -8, -8, -10, -10, -12, -12, -12, -12
> > -};
> > -
> >   static int dsi_populate_dsc_params(struct msm_dsi_host *msm_host, 
> > struct drm_dsc_config *dsc)
> >   {
> > -    int i;
> > -    u16 bpp = dsc->bits_per_pixel >> 4;
> > -
> >       if (dsc->bits_per_pixel & 0xf) {
> >           DRM_DEV_ERROR(&msm_host->pdev->dev, "DSI does not support 
> > fractional bits_per_pixel\n");
> >           return -EINVAL;
> > @@ -1852,50 +1832,16 @@ static int dsi_populate_dsc_params(struct 
> > msm_dsi_host *msm_host, struct drm_dsc
> >           return -EOPNOTSUPP;
> >       }
> > -    dsc->rc_model_size = 8192;
> > -    dsc->first_line_bpg_offset = 12;
> > -    dsc->rc_edge_factor = 6;
> > -    dsc->rc_tgt_offset_high = 3;
> > -    dsc->rc_tgt_offset_low = 3;
> > -    dsc->simple_422 = 0;
> > -    dsc->convert_rgb = 1;
> > -    dsc->vbr_enable = 0;
> > -
> > -    /* handle only bpp = bpc = 8 */
> > -    for (i = 0; i < DSC_NUM_BUF_RANGES - 1 ; i++)
> > -        dsc->rc_buf_thresh[i] = dsi_dsc_rc_buf_thresh[i];
> > -
> > -    for (i = 0; i < DSC_NUM_BUF_RANGES; i++) {
> > -        dsc->rc_range_params[i].range_min_qp = min_qp[i];
> > -        dsc->rc_range_params[i].range_max_qp = max_qp[i];
> > -        /*
> > -         * Range BPG Offset contains two's-complement signed values 
> > that fill
> > -         * 8 bits, yet the registers and DCS PPS field are only 6 
> > bits wide.
> > -         */
> > -        dsc->rc_range_params[i].range_bpg_offset = bpg_offset[i] & 
> > DSC_RANGE_BPG_OFFSET_MASK;
> > -    }
> > -
> > -    dsc->initial_offset = 6144;        /* Not bpp 12 */
> > -    if (bpp != 8)
> > -        dsc->initial_offset = 2048;    /* bpp = 12 */
> > -
> > -    if (dsc->bits_per_component <= 10)
> > -        dsc->mux_word_size = DSC_MUX_WORD_SIZE_8_10_BPC;
> > -    else
> > -        dsc->mux_word_size = DSC_MUX_WORD_SIZE_12_BPC;
> > -
> > -    dsc->initial_xmit_delay = 512;
> > -    dsc->initial_scale_value = 32;
> > -    dsc->first_line_bpg_offset = 12;
> > -    dsc->line_buf_depth = dsc->bits_per_component + 1;
> > -
> > -    /* bpc 8 */
> > -    dsc->flatness_min_qp = 3;
> > -    dsc->flatness_max_qp = 12;
> > -    dsc->rc_quant_incr_limit0 = 11;
> > -    dsc->rc_quant_incr_limit1 = 11;
> > -
> > -    return drm_dsc_compute_rc_parameters(dsc);
> > +    /*
> > +     * NOTE:
> > +     * dsc->dsc_version_major, dsc->dsc_version_minor
> > +     * dsc->bits_per_pixel,
> > +     * dsc->bits_per_component,
> > +     * dsc->native_422, dsc->native_420
> > +     *
> > +     * above parameters must be populated
>
> Comments
> In Yoda style
> written should be not.
>
> > +     */
> > +    return dpu_dsc_populate_dsc_config(dsc, 0);
> >   }
> >   static int dsi_host_parse_dt(struct msm_dsi_host *msm_host)