drm/gma500: Remove GTT roll support

GTT roll support was used to accelerate fb panning on some machines.
Unfortunately this never worked properly with multiple monitors and
caused issues on others where the framebuffer wouldn't fit in stolen
memory. Let's remove it!

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20201028143608.1284-1-patrik.r.jakobsson@gmail.com

1 files changed, 12 insertions, 84 deletions

diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c
index 5ede24fb44ae..2d64c58607f5 100644
--- a/drivers/gpu/drm/gma500/framebuffer.c
+++ b/drivers/gpu/drm/gma500/framebuffer.c
@@ -76,27 +76,6 @@ static int psbfb_setcolreg(unsigned regno, unsigned red, unsigned green,
 	return 0;
 }
 
-static int psbfb_pan(struct fb_var_screeninfo *var, struct fb_info *info)
-{
-	struct drm_fb_helper *fb_helper = info->par;
-	struct drm_framebuffer *fb = fb_helper->fb;
-	struct drm_device *dev = fb->dev;
-	struct gtt_range *gtt = to_gtt_range(fb->obj[0]);
-
-	/*
-	 *	We have to poke our nose in here. The core fb code assumes
-	 *	panning is part of the hardware that can be invoked before
-	 *	the actual fb is mapped. In our case that isn't quite true.
-	 */
-	if (gtt->npage) {
-		/* GTT roll shifts in 4K pages, we need to shift the right
-		   number of pages */
-		int pages = info->fix.line_length >> 12;
-		psb_gtt_roll(dev, gtt, var->yoffset * pages);
-	}
-        return 0;
-}
-
 static vm_fault_t psbfb_vm_fault(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
@@ -176,17 +155,6 @@ static const struct fb_ops psbfb_ops = {
 	.fb_sync = psbfb_sync,
 };
 
-static const struct fb_ops psbfb_roll_ops = {
-	.owner = THIS_MODULE,
-	DRM_FB_HELPER_DEFAULT_OPS,
-	.fb_setcolreg = psbfb_setcolreg,
-	.fb_fillrect = drm_fb_helper_cfb_fillrect,
-	.fb_copyarea = drm_fb_helper_cfb_copyarea,
-	.fb_imageblit = drm_fb_helper_cfb_imageblit,
-	.fb_pan_display = psbfb_pan,
-	.fb_mmap = psbfb_mmap,
-};
-
 static const struct fb_ops psbfb_unaccel_ops = {
 	.owner = THIS_MODULE,
 	DRM_FB_HELPER_DEFAULT_OPS,
@@ -312,8 +280,6 @@ static int psbfb_create(struct drm_fb_helper *fb_helper,
 	int ret;
 	struct gtt_range *backing;
 	u32 bpp, depth;
-	int gtt_roll = 0;
-	int pitch_lines = 0;
 
 	mode_cmd.width = sizes->surface_width;
 	mode_cmd.height = sizes->surface_height;
@@ -324,50 +290,15 @@ static int psbfb_create(struct drm_fb_helper *fb_helper,
 	if (bpp == 24)
 		bpp = 32;
 
-	do {
-		/*
-		 * Acceleration via the GTT requires pitch to be
-		 * power of two aligned. Preferably page but less
-		 * is ok with some fonts
-		 */
-        	mode_cmd.pitches[0] =  ALIGN(mode_cmd.width * ((bpp + 7) / 8), 4096 >> pitch_lines);
-
-        	size = mode_cmd.pitches[0] * mode_cmd.height;
-        	size = ALIGN(size, PAGE_SIZE);
-
-		/* Allocate the fb in the GTT with stolen page backing */
-		backing = psbfb_alloc(dev, size);
-
-		if (pitch_lines)
-			pitch_lines *= 2;
-		else
-			pitch_lines = 1;
-		gtt_roll++;
-	} while (backing == NULL && pitch_lines <= 16);
-
-	/* The final pitch we accepted if we succeeded */
-	pitch_lines /= 2;
-
-	if (backing == NULL) {
-		/*
-		 *	We couldn't get the space we wanted, fall back to the
-		 *	display engine requirement instead.  The HW requires
-		 *	the pitch to be 64 byte aligned
-		 */
-
-		gtt_roll = 0;	/* Don't use GTT accelerated scrolling */
-		pitch_lines = 64;
-
-		mode_cmd.pitches[0] =  ALIGN(mode_cmd.width * ((bpp + 7) / 8), 64);
-
-		size = mode_cmd.pitches[0] * mode_cmd.height;
-		size = ALIGN(size, PAGE_SIZE);
-
-		/* Allocate the framebuffer in the GTT with stolen page backing */
-		backing = psbfb_alloc(dev, size);
-		if (backing == NULL)
-			return -ENOMEM;
-	}
+	mode_cmd.pitches[0] = ALIGN(mode_cmd.width * DIV_ROUND_UP(bpp, 8), 64);
+
+	size = mode_cmd.pitches[0] * mode_cmd.height;
+	size = ALIGN(size, PAGE_SIZE);
+
+	/* Allocate the framebuffer in the GTT with stolen page backing */
+	backing = psbfb_alloc(dev, size);
+	if (backing == NULL)
+		return -ENOMEM;
 
 	memset(dev_priv->vram_addr + backing->offset, 0, size);
 
@@ -387,17 +318,14 @@ static int psbfb_create(struct drm_fb_helper *fb_helper,
 
 	fb_helper->fb = fb;
 
-	if (dev_priv->ops->accel_2d && pitch_lines > 8)	/* 2D engine */
+	if (dev_priv->ops->accel_2d)	/* 2D engine */
 		info->fbops = &psbfb_ops;
-	else if (gtt_roll) {	/* GTT rolling seems best */
-		info->fbops = &psbfb_roll_ops;
-		info->flags |= FBINFO_HWACCEL_YPAN;
-	} else	/* Software */
+	else	/* Software */
 		info->fbops = &psbfb_unaccel_ops;
 
 	info->fix.smem_start = dev->mode_config.fb_base;
 	info->fix.smem_len = size;
-	info->fix.ywrapstep = gtt_roll;
+	info->fix.ywrapstep = 0;
 	info->fix.ypanstep = 0;
 
 	/* Accessed stolen memory directly */