Re: [PATCH 3.13.y-ckt 019/103] drm/i915: Swap primary planes on gen2 for FBC

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Feb 18, 2015 at 04:31:46PM -0800, Kamal Mostafa wrote:
> 3.13.11-ckt16 -stable review patch.  If anyone has any objections, please let me know.
> 
> ------------------
> 
> From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
> 
> commit 1f1c2e2468f937cefd6bcb645c959c7b5d9821df upstream.
> 
> Only plane A is FBC capable on gen2 (like gen3), but the panel fitter
> is hooked up to pipe B, so we want to prefer pipe B + plane A.

FBC doesn't even work on gen2 (still missing my stolen mem patches) so
this patch doesn't really seem like stable material to me. But I take
it you backported it to get the prepare_page_flip() patch to apply cleanly?

If you really want to do that, then you should also backport

commit 38af6096781e2ed3d83b970218dedfe98e2f8f9c
Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
Date:   Tue Jan 7 16:15:37 2014 +0200

    drm/i915: Don't swap planes on 830M

othwerwise you may have some angry 830 users knocking at the door,
assuming there are more than two of us :) Although 830 support has
been more or less broken since forever until 3.18 so maybe no one
would notice anyway.

> 
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
> [danvet: Add the code comment Chris requested in his review.]
> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> 
> Signed-off-by: Kamal Mostafa <kamal@canonical.com>
> ---
>  drivers/gpu/drm/i915/i915_irq.c      | 14 +++++++++-----
>  drivers/gpu/drm/i915/intel_display.c |  7 +++++--
>  2 files changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 3a10da2..5e0b5e4 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3155,10 +3155,10 @@ static int i8xx_irq_postinstall(struct drm_device *dev)
>   * Returns true when a page flip has completed.
>   */
>  static bool i8xx_handle_vblank(struct drm_device *dev,
> -			       int pipe, u16 iir)
> +			       int plane, int pipe, u32 iir)
>  {
>  	drm_i915_private_t *dev_priv = dev->dev_private;
> -	u16 flip_pending = DISPLAY_PLANE_FLIP_PENDING(pipe);
> +	u16 flip_pending = DISPLAY_PLANE_FLIP_PENDING(plane);
>  
>  	if (!drm_handle_vblank(dev, pipe))
>  		return false;
> @@ -3166,7 +3166,7 @@ static bool i8xx_handle_vblank(struct drm_device *dev,
>  	if ((iir & flip_pending) == 0)
>  		return false;
>  
> -	intel_prepare_page_flip(dev, pipe);
> +	intel_prepare_page_flip(dev, plane);
>  
>  	/* We detect FlipDone by looking for the change in PendingFlip from '1'
>  	 * to '0' on the following vblank, i.e. IIR has the Pendingflip
> @@ -3235,9 +3235,13 @@ static irqreturn_t i8xx_irq_handler(int irq, void *arg)
>  			notify_ring(dev, &dev_priv->ring[RCS]);
>  
>  		for_each_pipe(pipe) {
> +			int plane = pipe;
> +			if (IS_MOBILE(dev))
> +				plane = !plane;
> +
>  			if (pipe_stats[pipe] & PIPE_VBLANK_INTERRUPT_STATUS &&
> -			    i8xx_handle_vblank(dev, pipe, iir))
> -				flip_mask &= ~DISPLAY_PLANE_FLIP_PENDING(pipe);
> +			    i8xx_handle_vblank(dev, plane, pipe, iir))
> +				flip_mask &= ~DISPLAY_PLANE_FLIP_PENDING(plane);
>  
>  			if (pipe_stats[pipe] & PIPE_CRC_DONE_INTERRUPT_STATUS)
>  				i9xx_pipe_crc_irq_handler(dev, pipe);
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 2d2c1e1..ae3bc77 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9949,10 +9949,13 @@ static void intel_crtc_init(struct drm_device *dev, int pipe)
>  		intel_crtc->lut_b[i] = i;
>  	}
>  
> -	/* Swap pipes & planes for FBC on pre-965 */
> +	/*
> +	 * On gen2/3 only plane A can do fbc, but the panel fitter and lvds port
> +	 * is hooked to plane B. Hence we want plane A feeding pipe B.
> +	 */
>  	intel_crtc->pipe = pipe;
>  	intel_crtc->plane = pipe;
> -	if (IS_MOBILE(dev) && IS_GEN3(dev)) {
> +	if (IS_MOBILE(dev) && INTEL_INFO(dev)->gen < 4) {
>  		DRM_DEBUG_KMS("swapping pipes & planes for FBC\n");
>  		intel_crtc->plane = !pipe;
>  	}
> -- 
> 1.9.1

-- 
Ville Syrjälä
Intel OTC