* Re: HDMI timing parameters problem
2010-06-04 15:27 HDMI timing parameters problem Guennadi Liakhovetski
@ 2010-06-04 17:36 ` Geert Uytterhoeven
2010-06-04 19:54 ` Guennadi Liakhovetski
2010-06-04 20:54 ` Geert Uytterhoeven
2 siblings, 0 replies; 4+ messages in thread
From: Geert Uytterhoeven @ 2010-06-04 17:36 UTC (permalink / raw)
To: linux-fbdev
On Fri, Jun 4, 2010 at 17:27, Guennadi Liakhovetski
<g.liakhovetski@gmx.de> wrote:
> 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@74.25MHz. 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?
The timings I calculated from the HDTV specs for ps3fb are slightly different.
But you may want to give them a try.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: HDMI timing parameters problem
2010-06-04 15:27 HDMI timing parameters problem Guennadi Liakhovetski
2010-06-04 17:36 ` Geert Uytterhoeven
@ 2010-06-04 19:54 ` Guennadi Liakhovetski
2010-06-04 20:54 ` Geert Uytterhoeven
2 siblings, 0 replies; 4+ messages in thread
From: Guennadi Liakhovetski @ 2010-06-04 19:54 UTC (permalink / raw)
To: linux-fbdev
Hi Geert
On Fri, 4 Jun 2010, Geert Uytterhoeven wrote:
> On Fri, Jun 4, 2010 at 17:27, Guennadi Liakhovetski
> <g.liakhovetski@gmx.de> wrote:
> > 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@74.25MHz. 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?
>
> The timings I calculated from the HDTV specs for ps3fb are slightly different.
> But you may want to give them a try.
You're referring to this mode from drivers/video/ps3fb.c:
}, {
/* SXGA */
"sxga", 60, 1280, 1024, 9259, 248, 48, 38, 1, 112, 3,
FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT, FB_VMODE_NONINTERLACED,
FB_MODE_IS_VESA
}, {
right? Interestingly, those are exactly the values, that my monitor is
reporting, also quoted at the top of this mail:
248 + 48 + 112 = 408
38 + 1 + 3 = 42
, and I cannot seem to get them to work:( hmm...
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: HDMI timing parameters problem
2010-06-04 15:27 HDMI timing parameters problem Guennadi Liakhovetski
2010-06-04 17:36 ` Geert Uytterhoeven
2010-06-04 19:54 ` Guennadi Liakhovetski
@ 2010-06-04 20:54 ` Geert Uytterhoeven
2 siblings, 0 replies; 4+ messages in thread
From: Geert Uytterhoeven @ 2010-06-04 20:54 UTC (permalink / raw)
To: linux-fbdev
On Fri, Jun 4, 2010 at 21:54, Guennadi Liakhovetski
<g.liakhovetski@gmx.de> wrote:
> On Fri, 4 Jun 2010, Geert Uytterhoeven wrote:
>> On Fri, Jun 4, 2010 at 17:27, Guennadi Liakhovetski
>> <g.liakhovetski@gmx.de> wrote:
>> > 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@74.25MHz. 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?
>>
>> The timings I calculated from the HDTV specs for ps3fb are slightly different.
>> But you may want to give them a try.
>
> You're referring to this mode from drivers/video/ps3fb.c:
>
> }, {
> /* SXGA */
> "sxga", 60, 1280, 1024, 9259, 248, 48, 38, 1, 112, 3,
> FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT, FB_VMODE_NONINTERLACED,
> FB_MODE_IS_VESA
> }, {
>
> right? Interestingly, those are exactly the values, that my monitor is
> reporting, also quoted at the top of this mail:
>
> 248 + 48 + 112 = 408
> 38 + 1 + 3 = 42
>
> , and I cannot seem to get them to work:( hmm...
I didn't check the 1280x1024 mode, only the 1280x720 mode (cfr. 720pf in ps3fb).
Perhaps it's a sync polarity issue? Traditionally, you have positive
and negative
sync pulses, but HDTV uses a tri-state sync pulse (don't remember the
exact details).
The HDMI chip may support HDTV sync only.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 4+ messages in thread