On Wed, Jun 26, 2024 at 1:49 AM Jessica Zhang <quic_jesszhan@xxxxxxxxxxx> wrote: > > > > On 6/25/2024 5:13 AM, zhaoxiong lv wrote: > > On Tue, Jun 25, 2024 at 7:41 AM Jessica Zhang <quic_jesszhan@xxxxxxxxxxx> wrote: > >> > >> > >> > >> On 6/24/2024 7:19 AM, Zhaoxiong Lv wrote: > >>> Currently, the init_code of the jd9365da driver is placed > >>> in the enable() function and sent, but this seems to take > >>> a long time. It takes 17ms to send each instruction (an init > >>> code consists of about 200 instructions), so it takes > >>> about 3.5s to send the init_code. So we moved the sending > >>> of the inti_code to the prepare() function, and each > >>> instruction seemed to take only 25μs. > >>> > >>> We checked the DSI host and found that the difference in > >>> command sending time is caused by the different modes of > >>> the DSI host in prepare() and enable() functions. > >>> Our DSI Host only supports sending cmd in LP mode, The > >>> prepare() function can directly send init_code (LP->cmd) > >>> in LP mode, but the enable() function is in HS mode and > >>> needs to switch to LP mode before sending init code > >>> (HS->LP->cmd->HS). Therefore, it takes longer to send > >>> the command. > >>> > >>> Signed-off-by: Zhaoxiong Lv <lvzhaoxiong@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> > >> > >> Hi Zhaoxiong, > >> > >> Just curious, if the host expects that commands are sent in LP mode, why > >> isn't the MIPI_DSI_MODE_LPM flag set before sending the DCS commands? > >> > >> Thanks, > >> > >> Jessica Zhang > > > > hi jessica > > > > We have tried to set dsi->mode_flags to MIPI_DSI_MODE_LPM in the > > probe() function, > > but this seems to still happen. MTK colleagues believe that the host > > dsi configuration is > > still in LP mode during the prepare() function, and when in the > > enable() function, the host > > dsi is already in HS mode. However, since the command must be sent in > > LP mode, it will > > switch back and forth between HS->LP->HS. > > > > Add Mediatek colleagues（shuijing.li@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx） > > Got it. Even drivers that call their init commands in prepare() set the > LPM flag [1][2] when applicable so I was just wondering why this driver > doesn't seem to set LPM at all even though it is going into LP mode. > > [1] > https://elixir.bootlin.com/linux/v6.10-rc5/source/drivers/gpu/drm/panel/panel-visionox-vtdr6130.c#L46 > > [2] > https://elixir.bootlin.com/linux/v6.10-rc5/source/drivers/gpu/drm/panel/panel-visionox-r66451.c#L46 hi jessica The initial default setting of our host DSI is the LP mode. > > > > > > >> > >>> --- > >>> Changes between V5 and V4: > >>> - 1. No changes. > >>> > >>> V4:https://lore.kernel.org/all/20240620080509.18504-2-lvzhaoxiong@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > >>> > >>> Changes between V4 and V3: > >>> - 1. Only move mipi_dsi_dcs_write_buffer from enable() function to prepare() function, > >>> - and no longer use mipi_dsi_dcs_write_seq_multi. > >>> > >>> V3:https://lore.kernel.org/all/20240614145510.22965-2-lvzhaoxiong@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > >>> > >>> --- > >>> .../gpu/drm/panel/panel-jadard-jd9365da-h3.c | 24 +++++++++---------- > >>> 1 file changed, 11 insertions(+), 13 deletions(-) > >>> > >>> diff --git a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c > >>> index 4879835fe101..a9c483a7b3fa 100644 > >>> --- a/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c > >>> +++ b/drivers/gpu/drm/panel/panel-jadard-jd9365da-h3.c > >>> @@ -52,21 +52,9 @@ static int jadard_enable(struct drm_panel *panel) > >>> { > >>> struct device *dev = panel->dev; > >>> struct jadard *jadard = panel_to_jadard(panel); > >>> - const struct jadard_panel_desc *desc = jadard->desc; > >>> struct mipi_dsi_device *dsi = jadard->dsi; > >>> - unsigned int i; > >>> int err; > >>> > >>> - msleep(10); > >>> - > >>> - for (i = 0; i < desc->num_init_cmds; i++) { > >>> - const struct jadard_init_cmd *cmd = &desc->init_cmds[i]; > >>> - > >>> - err = mipi_dsi_dcs_write_buffer(dsi, cmd->data, JD9365DA_INIT_CMD_LEN); > >>> - if (err < 0) > >>> - return err; > >>> - } > >>> - > >>> msleep(120); > >>> > >>> err = mipi_dsi_dcs_exit_sleep_mode(dsi); > >>> @@ -100,6 +88,8 @@ static int jadard_disable(struct drm_panel *panel) > >>> static int jadard_prepare(struct drm_panel *panel) > >>> { > >>> struct jadard *jadard = panel_to_jadard(panel); > >>> + const struct jadard_panel_desc *desc = jadard->desc; > >>> + unsigned int i; > >>> int ret; > >>> > >>> ret = regulator_enable(jadard->vccio); > >>> @@ -117,7 +107,15 @@ static int jadard_prepare(struct drm_panel *panel) > >>> msleep(10); > >>> > >>> gpiod_set_value(jadard->reset, 1); > >>> - msleep(120); > >>> + msleep(130); > >>> + > >>> + for (i = 0; i < desc->num_init_cmds; i++) { > >>> + const struct jadard_init_cmd *cmd = &desc->init_cmds[i]; > >>> + > >>> + ret = mipi_dsi_dcs_write_buffer(dsi, cmd->data, JD9365DA_INIT_CMD_LEN); > >>> + if (ret < 0) > >>> + return ret; > >>> + } > >>> > >>> return 0; > >>> } > >>> -- > >>> 2.17.1 > >>>
