[PATCH] drm/i915: Disable high-precision vblank timestamping for UMS

[Chris Clayton]

Hi Chris,

On Sunday 23 January 2011, Chris Wilson wrote:
> We only have sufficient information for accurate (sub-frame) timestamping
> when the modesetting is under our control.
>
> Reported-by: Chris Clayton <chris2553 at googlemail.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  drivers/gpu/drm/i915/i915_drv.c |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c
> b/drivers/gpu/drm/i915/i915_drv.c index 59eb19b..66796bb 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -752,6 +752,9 @@ static int __init i915_init(void)
>  		driver.driver_features &= ~DRIVER_MODESET;
>  #endif
>
> +	if (!(driver.driver_features & DRIVER_MODESET))
> +		driver.get_vblank_timestamp = NULL;
> +
>  	return drm_init(&driver);
>  }

With this patch (and the earlier one) applied, X still doesn't start. At the end 
of xorg's log file I see:

Fatal server error:
Failure to wait for IRQ: No such device

and in the kernel log I see:

Jan 23 11:15:25 upstairs kernel: [drm] Initialized drm 1.1.0 20060810
Jan 23 11:15:26 upstairs kernel: pci 0000:00:02.0: PCI INT A -> GSI 16 (level, 
low) -> IRQ 16
Jan 23 11:15:26 upstairs kernel: pci 0000:00:02.0: setting latency timer to 64
Jan 23 11:15:26 upstairs kernel: ioremap error for 0xbdce0000-0xbdce3000, 
requested 0x10, got 0x0
Jan 23 11:15:26 upstairs kernel: [drm] Supports vblank timestamp caching Rev 1 
(10.10.2010).
Jan 23 11:15:26 upstairs kernel: [drm] No driver support for vblank timestamp 
query.
Jan 23 11:15:26 upstairs kernel: [drm] Initialized i915 1.6.0 20080730 for 
0000:00:02.0 on minor 0

Chris

-- 
The more I see, the more I know. The more I know, the less I understand. 
Changing Man - Paul Weller