| Message ID | 20230608-b4-add-burst-mode-v2-1-2ff468457d46@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm/msm/dsi: Enable BURST_MODE for command mode for DSI 6G v1.3+ | expand |
On 27/06/2023 23:31, Jessica Zhang wrote: > During a frame transfer in command mode, there could be frequent > LP11 <-> HS transitions when multiple DCS commands are sent mid-frame or > if the DSI controller is running on slow clock and is throttled. To > minimize frame latency due to these transitions, it is recommended to > send the frame in a single burst. > > This feature is supported for DSI 6G 1.3 and above, thus enable burst > mode if supported. > > Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> > --- > Changes in v2: > - Moved MDP_CTRL2 register setting to dsi_ctrl_config() (Dmitry/Marijn) > - Read previous value of MDP_CTRL2 register before writing to it > (Dmitry) > - Link to v1: https://lore.kernel.org/r/20230608-b4-add-burst-mode-v1-1-55dfbcfada55@quicinc.com > --- > drivers/gpu/drm/msm/dsi/dsi_host.c | 7 +++++++ > 1 file changed, 7 insertions(+) Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > > diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c > index 3f6dfb4f9d5a..cdb404885f3c 100644 > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c > @@ -752,6 +752,13 @@ static void dsi_ctrl_enable(struct msm_dsi_host *msm_host, > /* Always insert DCS command */ > data |= DSI_CMD_CFG1_INSERT_DCS_COMMAND; > dsi_write(msm_host, REG_DSI_CMD_CFG1, data); > + > + if (msm_host->cfg_hnd->major == MSM_DSI_VER_MAJOR_6G && > + msm_host->cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V1_3) { Nit: please intent in future to the same level (vim: "set cino=(0"). > + data = dsi_read(msm_host, REG_DSI_CMD_MODE_MDP_CTRL2); > + data |= DSI_CMD_MODE_MDP_CTRL2_BURST_MODE; > + dsi_write(msm_host, REG_DSI_CMD_MODE_MDP_CTRL2, data); > + } > } > > dsi_write(msm_host, REG_DSI_CMD_DMA_CTRL, > > --- > base-commit: a0364260213c96f6817f7e85cdce293cb743460f > change-id: 20230608-b4-add-burst-mode-a5bb144069fa > > Best regards,
On Tue, 27 Jun 2023 13:31:45 -0700, Jessica Zhang wrote: > During a frame transfer in command mode, there could be frequent > LP11 <-> HS transitions when multiple DCS commands are sent mid-frame or > if the DSI controller is running on slow clock and is throttled. To > minimize frame latency due to these transitions, it is recommended to > send the frame in a single burst. > > This feature is supported for DSI 6G 1.3 and above, thus enable burst > mode if supported. > > [...] Applied, thanks! [1/1] drm/msm/dsi: Enable BURST_MODE for command mode for DSI 6G v1.3+ https://gitlab.freedesktop.org/lumag/msm/-/commit/4ac447e89e71 Best regards,
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 3f6dfb4f9d5a..cdb404885f3c 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -752,6 +752,13 @@ static void dsi_ctrl_enable(struct msm_dsi_host *msm_host, /* Always insert DCS command */ data |= DSI_CMD_CFG1_INSERT_DCS_COMMAND; dsi_write(msm_host, REG_DSI_CMD_CFG1, data); + + if (msm_host->cfg_hnd->major == MSM_DSI_VER_MAJOR_6G && + msm_host->cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V1_3) { + data = dsi_read(msm_host, REG_DSI_CMD_MODE_MDP_CTRL2); + data |= DSI_CMD_MODE_MDP_CTRL2_BURST_MODE; + dsi_write(msm_host, REG_DSI_CMD_MODE_MDP_CTRL2, data); + } } dsi_write(msm_host, REG_DSI_CMD_DMA_CTRL,
During a frame transfer in command mode, there could be frequent LP11 <-> HS transitions when multiple DCS commands are sent mid-frame or if the DSI controller is running on slow clock and is throttled. To minimize frame latency due to these transitions, it is recommended to send the frame in a single burst. This feature is supported for DSI 6G 1.3 and above, thus enable burst mode if supported. Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> --- Changes in v2: - Moved MDP_CTRL2 register setting to dsi_ctrl_config() (Dmitry/Marijn) - Read previous value of MDP_CTRL2 register before writing to it (Dmitry) - Link to v1: https://lore.kernel.org/r/20230608-b4-add-burst-mode-v1-1-55dfbcfada55@quicinc.com --- drivers/gpu/drm/msm/dsi/dsi_host.c | 7 +++++++ 1 file changed, 7 insertions(+) --- base-commit: a0364260213c96f6817f7e85cdce293cb743460f change-id: 20230608-b4-add-burst-mode-a5bb144069fa Best regards,