On Thu, 11 Jul 2013 16:02:27 +0800
Xiong Zhang <xiong.y.zhang at intel.com> wrote:
> display.crtc_mode_set will increase pll->refcount, but no one will
> decrease pll->refcount when freeze gpu. So when gpu resume from freeze,
> pll->refcount is still larger than zero. This is abnormal
>
> Without this patch, connecting vga screen on Haswell platform, there
> are following results:
> 1. when resume S3, call trace exist in intel_ddi_put_crtc_pll()
> 2. when resume s4, vga monitor is black. because intel_ddi_pll_mode_set()
> return false and haswell_crtc_mode_set() exit without setting mode
>
> With this patch, I don't find S3 and S4 regression on SandyBridge
> and IvyBridge platform connecting VGA, HDMI and DP screen.
>
> Signed-off-by: Xiong Zhang <xiong.y.zhang at intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 0485f43..0065735 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -575,8 +575,10 @@ static int i915_drm_freeze(struct drm_device *dev)
> * Disable CRTCs directly since we want to preserve sw state
> * for _thaw.
> */
> - list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
> + list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
> dev_priv->display.crtc_disable(crtc);
> + dev_priv->display.off(crtc);
> + }
>
> intel_modeset_suspend_hw(dev);
> }
The comment above this call indicates we'll trash the sw state if we
call ->off directly. Does suspend/resume still work both with and
without X with this patch applied? If we trash the sw state, the VT
switchless resume shouldn't work...
--
Jesse Barnes, Intel Open Source Technology Center
