| Message ID | 20230915204426.19011-1-quic_abhinavk@quicinc.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] drm/msm/dsi: skip the wait for video mode done if not applicable | expand |
On Fri, 15 Sept 2023 at 23:45, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote: > > dsi_wait4video_done() API waits for the DSI video mode engine to > become idle so that we can transmit the DCS commands in the > beginning of BLLP. However, with the current sequence, the MDP > timing engine is turned on after the panel's pre_enable() callback > which can send out the DCS commands needed to power up the panel. > > During those cases, this API will always timeout and print out the > error spam leading to long bootup times and log flooding. > > Fix this by checking if the DSI video engine was actually busy before > waiting for it to become idle otherwise this is a redundant wait. > > changes in v2: > - move the reg read below the video mode check > - minor fixes in commit text > > Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/34 > Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support") > Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > --- > drivers/gpu/drm/msm/dsi/dsi_host.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) >
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 0c4ec0530efc..1a2afe31fa86 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1075,9 +1075,21 @@ static void dsi_wait4video_done(struct msm_dsi_host *msm_host) static void dsi_wait4video_eng_busy(struct msm_dsi_host *msm_host) { + u32 data; + if (!(msm_host->mode_flags & MIPI_DSI_MODE_VIDEO)) return; + data = dsi_read(msm_host, REG_DSI_STATUS0); + + /* if video mode engine is not busy, its because + * either timing engine was not turned on or the + * DSI controller has finished transmitting the video + * data already, so no need to wait in those cases + */ + if (!(data & DSI_STATUS0_VIDEO_MODE_ENGINE_BUSY)) + return; + if (msm_host->power_on && msm_host->enabled) { dsi_wait4video_done(msm_host); /* delay 4 ms to skip BLLP */
dsi_wait4video_done() API waits for the DSI video mode engine to become idle so that we can transmit the DCS commands in the beginning of BLLP. However, with the current sequence, the MDP timing engine is turned on after the panel's pre_enable() callback which can send out the DCS commands needed to power up the panel. During those cases, this API will always timeout and print out the error spam leading to long bootup times and log flooding. Fix this by checking if the DSI video engine was actually busy before waiting for it to become idle otherwise this is a redundant wait. changes in v2: - move the reg read below the video mode check - minor fixes in commit text Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/34 Fixes: a689554ba6ed ("drm/msm: Initial add DSI connector support") Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com> --- drivers/gpu/drm/msm/dsi/dsi_host.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)