Hi all I'm trying to configure an HDMI controller on an ARM based SoC, and I cannot seem to find suitable values for blanking parameters. The monitor EDID reports 1280x1024@108MHz: H_ACTIVE = 1280 H_SYNC_OFFSET = 48 H_SYNC_WIDTH = 112 H_BLANKING = 408 V_ACTIVE = 1024 V_SYNC_OFFSET = 1 V_SYNC_WIDTH = 3 V_BLANKING = 42 The HDMI controller can be programmed in one of two modes: with a preset configuration or manually specifying each parameter. The only mode that somehow works up to now is the preset 1280x720@xxxxxxxxx With this mode the image on the monitor is stretched vertically, but it works. Unfortunately, the controller doesn't have any preset modes for 1280x1024 or for anything close enough. So, I have to support manual geometry configuration. To reduce the number of required changes, as a first step, I'm trying to achieve the same result in manual mode, as I've got with preset, by programming 1280x720. For this I've chosen the following configuration: .xres = 1280, .yres = 720, .left_margin = 224, .right_margin = 104, .hsync_len = 40, .upper_margin = 20, .lower_margin = 5, .vsync_len = 5, which is the same, as what I'm configuring my LCD controller with. This translates to H_ACTIVE = 1280 H_SYNC_OFFSET = 104 H_SYNC_WIDTH = 40 H_BLANKING = 368 V_ACTIVE = 720 V_SYNC_OFFSET = 5 V_SYNC_WIDTH = 5 V_BLANKING = 30 With it the monitor recognises the signal, the LED goes green, but there's no image. I've done a few more tests with various configurations, but so far with no success. Can anyone suggest how to debug this? How to find the proper video mode? Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
