Hello Tomi,
On 02/04/25 19:00, Tomi Valkeinen wrote:
> The timings calculation gets it wrong for DSI event mode, resulting in
> too large hbp value. Fix the issue by taking into account the
> pulse/event mode difference.
>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Jayesh Choudhary <j-choudhary@ti.com>
> ---
> drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 33 ++++++++++++++++++--------
> 1 file changed, 23 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
> index 62811631341b..9797e6faa29d 100644
> --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
> +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
> @@ -417,7 +417,8 @@
> #define DSI_OUTPUT_PORT 0
> #define DSI_INPUT_PORT(inputid) (1 + (inputid))
>
> -#define DSI_HBP_FRAME_OVERHEAD 12
> +#define DSI_HBP_FRAME_PULSE_OVERHEAD 12
> +#define DSI_HBP_FRAME_EVENT_OVERHEAD 16
I have also observed this 4B discrepancy for event-mode after comparing
the dsi packet sizes for each line type as per the dsi specifications.
> #define DSI_HSA_FRAME_OVERHEAD 14
> #define DSI_HFP_FRAME_OVERHEAD 6
> #define DSI_HSS_VSS_VSE_FRAME_OVERHEAD 4
> @@ -503,12 +504,18 @@ static int cdns_dsi_mode2cfg(struct cdns_dsi *dsi,
>
> bpp = mipi_dsi_pixel_format_to_bpp(output->dev->format);
>
> - dsi_cfg->hbp = dpi_to_dsi_timing(dpi_hbp + (sync_pulse ? 0 : dpi_hsa),
> - bpp, DSI_HBP_FRAME_OVERHEAD);
> + if (sync_pulse) {
> + dsi_cfg->hbp = dpi_to_dsi_timing(dpi_hbp, bpp,
> + DSI_HBP_FRAME_PULSE_OVERHEAD);
>
> - if (sync_pulse)
> - dsi_cfg->hsa =
> - dpi_to_dsi_timing(dpi_hsa, bpp, DSI_HSA_FRAME_OVERHEAD);
> + dsi_cfg->hsa = dpi_to_dsi_timing(dpi_hsa, bpp,
> + DSI_HSA_FRAME_OVERHEAD);
> + } else {
> + dsi_cfg->hbp = dpi_to_dsi_timing(dpi_hbp + dpi_hsa, bpp,
> + DSI_HBP_FRAME_EVENT_OVERHEAD);
> +
> + dsi_cfg->hsa = 0;
> + }
>
> dsi_cfg->hact = dpi_to_dsi_timing(dpi_hact, bpp, 0);
>
> @@ -532,9 +539,12 @@ static int cdns_dsi_adjust_phy_config(struct cdns_dsi *dsi,
> unsigned int dsi_hfp_ext;
> unsigned int lanes = output->dev->lanes;
>
> - dsi_htotal = dsi_cfg->hbp + DSI_HBP_FRAME_OVERHEAD;
> - if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
> + if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
> + dsi_htotal = dsi_cfg->hbp + DSI_HBP_FRAME_PULSE_OVERHEAD;
> dsi_htotal += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD;
> + } else {
> + dsi_htotal = dsi_cfg->hbp + DSI_HBP_FRAME_EVENT_OVERHEAD;
> + }
>
> dsi_htotal += dsi_cfg->hact;
> dsi_htotal += dsi_cfg->hfp + DSI_HFP_FRAME_OVERHEAD;
> @@ -607,9 +617,12 @@ static int cdns_dsi_check_conf(struct cdns_dsi *dsi,
> return -EINVAL;
> }
>
> - dsi_hss_hsa_hse_hbp = dsi_cfg->hbp + DSI_HBP_FRAME_OVERHEAD;
> - if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
> + if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
> + dsi_hss_hsa_hse_hbp = dsi_cfg->hbp + DSI_HBP_FRAME_PULSE_OVERHEAD;
> dsi_hss_hsa_hse_hbp += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD;
> + } else {
> + dsi_hss_hsa_hse_hbp = dsi_cfg->hbp + DSI_HBP_FRAME_EVENT_OVERHEAD;
> + }
>
> /*
> * Make sure DPI(HFP) > DSI(HSS+HSA+HSE+HBP) to guarantee that the FIFO
>
Thanks,
Jayesh