TDA4VL-Q1: How to set output resolution of eDP-1 in Linux SDK?

Hi Jeff,

There were some issues in earlier SDK for reading EDID, and a hack was put in place to hardcode for 800x600 resolution which is supported by most displays: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/commit/drivers/gpu/drm/panel/panel-edp.c?h=ti-linux-6.6.y&id=bea74070e3f75d0175662ac068114a0c03566e22

Fixes are planned to be upstreamed in the upcoming 11.1 SDK: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/log/drivers/gpu/drm?h=ti-linux-6.12.y&qt=grep&q=panel-edp

So as some options, you can move to upcoming 11.1 SDK once it releases, or hardcode 1080p resolutions into panel-edp.c

Regards,

Takuma

Hi Takuma,

We modify the panel-edp.c as:

and get all black display. Here is the kmsprint result & boot log

Connector 0 (40) DP-1 (disconnected)
Encoder 0 (39) NONE
Connector 1 (50) eDP-1 (connected)
Encoder 1 (49) NONE
Crtc 1 (48) 1920x1080@60.00 148.500 1920/88/44/148/- 1080/4/5/36/- 60 (60.00) 0xa 0x48
Plane 1 (41) fb-id: 66 (crtcs: 0 1) 0,0 1920x1080 -> 0,0 1920x1080 (AR12 AB12 RA12 RG16 BG16 AR15 AB15 AR24 AB24 RA24 BA24 RG24 BG24 AR30 AB30 XR12 XB12 RX12 XR15 XB15 XR24 XB24 RX24 BX24 XR30 XB30 YUYV UYVY NV12)
FB 66 1920x1080

dp.log

Did something we do wrong?

BR,

Jeff

Hi Jeff,

Could you try this timing parameter if hardcoding for 1080p:

    .clock = 96000,
    .hdisplay = 1920,
    .hsync_start = 1920 + 72,
    .hsync_end = 1920 + 72 + 48,
    .htotal = 1920 + 72 + 48 + 120,
    .vdisplay = 1080,
    .vsync_start = 1080 + 6,
    .vsync_end = 1080 + 6 + 7,
    .vtotal = 1080 + 6 + 7 + 60,    

    .crtc_clock = 96000,
    .crtc_hdisplay = 1920,
    .crtc_hsync_start = 1920 + 72,
    .crtc_hsync_end = 1920 + 72 + 48,
    .crtc_htotal = 1920 + 72 + 48 + 120,
    .crtc_vdisplay = 1080,
    .crtc_vsync_start = 1080 + 6,
    .crtc_vsync_end = 1080 + 6 + 7,
    .crtc_vtotal = 1080 + 6 + 7 + 60, 

Above has worked for a monitor in the past.

Regards,

Takuma

Hi Takuma,

We still get black screen. Here is boot log & kmsprint result. It seems kernel got error while init cdns-dsi.

7532.dp.log

BR,

Jeff

Hi Jeff,

Then recommendation would be to move to newest SDK. The top 3 commit reverts the hack for hardcoding timing parameters: https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/log/drivers/gpu/drm?h=ti-linux-6.12.y&qt=grep&q=panel-edp

You can move to 11.0 SDK and revert the hack.

Regards,

Takuma