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
---
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
