Detecting screen disconnection

[Ely Levy]

sounds exactlly like what I need,
Anyone happen to know if it exists on i8xx and nvidia as well?


Ely Levy
System group
Hebrew University
Jerusalem Israel



On Sun, 31 Oct 2004, Vladimir Dergachev wrote:

>
>
> On Sun, 31 Oct 2004, Jon Smirl wrote:
>
> > On Sun, 31 Oct 2004 19:46:50 -0500 (EST), Vladimir Dergachev
> > <volodya at mindspring.com> wrote:
> >> ATI cards have hardware that can sense which inputs are connected or
> >> disconnected and even send an interrupt on changes.
> >
> > Do you have some sample code for this? I'm working on the radeon
> > driver right now and I can try and hook it in.
>
> No, I have never played with it - though it looks like fun.
>
> DAC_CNTL (and DAC_CNTL2) has bits that control this. Interestingly enough
> there is also a way to check for analog termination - I am not sure
> whether this is the same as CRT detection bits in a different place in
> the same register.
>
> I.e. I don't understand why would someone want to test analog termination
> if there is a different way to find out whether CRT is connected.
>
> It also appears that it is not possible to create an interrupt on hotplug
> of analog connection.
>
> Flat panels on the other hand can be detected quite easily - GEN_INT_CNTL
> has two bits for each flat panel.
>
> I imagine that as far as DRM driver interrupt handler is concerned it only
> needs to deal with bits 4 (primary FP) and 10 (FP2) in GEN_INT_CNTL and
> GEN_INT_STATUS.
>
> These bits appear to not require any other initialization - in particular
> TMDS and LVDS registers do not have any bits that need to be enabled in
> order for these to work.
>
>                       best
>
>                          Vladimir Dergachev
>
> PS: Patch for drm/shared-code/radeon_drv.h :
>
> Index: radeon_drv.h
> ===================================================================
> RCS file: /cvs/dri/drm/shared-core/radeon_drv.h,v
> retrieving revision 1.36
> diff -u -r1.36 radeon_drv.h
> --- radeon_drv.h        10 Oct 2004 05:52:19 -0000      1.36
> +++ radeon_drv.h        1 Nov 2004 02:38:46 -0000
> @@ -397,12 +397,18 @@
>
>   #define RADEON_GEN_INT_CNTL            0x0040
>   #      define RADEON_CRTC_VBLANK_MASK          (1 << 0)
> +#      define RADEON_FP_DETECT_ENABLE          (1 << 4)
> +#      define RADEON_FP2_DETECT_ENABLE         (1 << 10)
>   #      define RADEON_GUI_IDLE_INT_ENABLE       (1 << 19)
>   #      define RADEON_SW_INT_ENABLE             (1 << 25)
>
>   #define RADEON_GEN_INT_STATUS          0x0044
>   #      define RADEON_CRTC_VBLANK_STAT          (1 << 0)
>   #      define RADEON_CRTC_VBLANK_STAT_ACK      (1 << 0)
> +#      define RADEON_FP_DETECT_STAT            (1 << 4)
> +#      define RADEON_FP_DETECT_ACK             (1 << 4)
> +#      define RADEON_FP2_DETECT_STAT           (1 << 10)
> +#      define RADEON_FP_DETECT_ACK             (1 << 10)
>   #      define RADEON_GUI_IDLE_INT_TEST_ACK     (1 << 19)
>   #      define RADEON_SW_INT_TEST               (1 << 25)
>   #      define RADEON_SW_INT_TEST_ACK           (1 << 25)
>
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