Revert "OMAPFB: simplify locking"

This reverts commit b41deecbda70067b26a3a7704fdf967a7940935b.

The simpler locking causes huge latencies when two processes use the
omapfb, even if they use different framebuffers.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 59 insertions, 9 deletions

diff --git a/drivers/video/omap2/omapfb/omapfb-ioctl.c b/drivers/video/omap2/omapfb/omapfb-ioctl.c
index dccb158b0d0b..d30b45d72649 100644
--- a/drivers/video/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/omap2/omapfb/omapfb-ioctl.c
@@ -85,6 +85,16 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
                 goto out;
         }
 
+        /* Take the locks in a specific order to keep lockdep happy */
+        if (old_rg->id < new_rg->id) {
+                omapfb_get_mem_region(old_rg);
+                omapfb_get_mem_region(new_rg);
+        } else if (new_rg->id < old_rg->id) {
+                omapfb_get_mem_region(new_rg);
+                omapfb_get_mem_region(old_rg);
+        } else
+                omapfb_get_mem_region(old_rg);
+
         if (pi->enabled && !new_rg->size) {
                 /*
                  * This plane's memory was freed, can't enable it
@@ -136,6 +146,16 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
                         goto undo;
         }
 
+        /* Release the locks in a specific order to keep lockdep happy */
+        if (old_rg->id > new_rg->id) {
+                omapfb_put_mem_region(old_rg);
+                omapfb_put_mem_region(new_rg);
+        } else if (new_rg->id > old_rg->id) {
+                omapfb_put_mem_region(new_rg);
+                omapfb_put_mem_region(old_rg);
+        } else
+                omapfb_put_mem_region(old_rg);
+
         return 0;
 
  undo:
@@ -146,6 +166,15 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
 
         ovl->set_overlay_info(ovl, &old_info);
  put_mem:
+        /* Release the locks in a specific order to keep lockdep happy */
+        if (old_rg->id > new_rg->id) {
+                omapfb_put_mem_region(old_rg);
+                omapfb_put_mem_region(new_rg);
+        } else if (new_rg->id > old_rg->id) {
+                omapfb_put_mem_region(new_rg);
+                omapfb_put_mem_region(old_rg);
+        } else
+                omapfb_put_mem_region(old_rg);
  out:
         dev_err(fbdev->dev, "setup_plane failed\n");
 
@@ -195,10 +224,11 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
         if (display && display->driver->sync)
                 display->driver->sync(display);
 
-        mutex_lock(&fbi->mm_lock);
-
         rg = ofbi->region;
 
+        down_write_nested(&rg->lock, rg->id);
+        atomic_inc(&rg->lock_count);
+
         if (rg->size == size && rg->type == mi->type)
                 goto out;
 
@@ -231,7 +261,9 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
         }
 
  out:
-        mutex_unlock(&fbi->mm_lock);
+        atomic_dec(&rg->lock_count);
+        up_write(&rg->lock);
+
         return r;
 }
 
@@ -240,12 +272,14 @@ static int omapfb_query_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
         struct omapfb_info *ofbi = FB2OFB(fbi);
         struct omapfb2_mem_region *rg;
 
-        rg = ofbi->region;
+        rg = omapfb_get_mem_region(ofbi->region);
         memset(mi, 0, sizeof(*mi));
 
         mi->size = rg->size;
         mi->type = rg->type;
 
+        omapfb_put_mem_region(rg);
+
         return 0;
 }
 
@@ -284,10 +318,14 @@ int omapfb_set_update_mode(struct fb_info *fbi,
         if (mode != OMAPFB_AUTO_UPDATE && mode != OMAPFB_MANUAL_UPDATE)
                 return -EINVAL;
 
+        omapfb_lock(fbdev);
+
         d = get_display_data(fbdev, display);
 
-        if (d->update_mode == mode)
+        if (d->update_mode == mode) {
+                omapfb_unlock(fbdev);
                 return 0;
+        }
 
         r = 0;
 
@@ -303,6 +341,8 @@ int omapfb_set_update_mode(struct fb_info *fbi,
                         r = -EINVAL;
         }
 
+        omapfb_unlock(fbdev);
+
         return r;
 }
 
@@ -317,10 +357,14 @@ int omapfb_get_update_mode(struct fb_info *fbi,
         if (!display)
                 return -EINVAL;
 
+        omapfb_lock(fbdev);
+
         d = get_display_data(fbdev, display);
 
         *mode = d->update_mode;
 
+        omapfb_unlock(fbdev);
+
         return 0;
 }
 
@@ -380,10 +424,13 @@ static int omapfb_set_color_key(struct fb_info *fbi,
                 struct omapfb_color_key *ck)
 {
         struct omapfb_info *ofbi = FB2OFB(fbi);
+        struct omapfb2_device *fbdev = ofbi->fbdev;
         int r;
         int i;
         struct omap_overlay_manager *mgr = NULL;
 
+        omapfb_lock(fbdev);
+
         for (i = 0; i < ofbi->num_overlays; i++) {
                 if (ofbi->overlays[i]->manager) {
                         mgr = ofbi->overlays[i]->manager;
@@ -398,6 +445,8 @@ static int omapfb_set_color_key(struct fb_info *fbi,
 
         r = _omapfb_set_color_key(mgr, ck);
 err:
+        omapfb_unlock(fbdev);
+
         return r;
 }
 
@@ -405,10 +454,13 @@ static int omapfb_get_color_key(struct fb_info *fbi,
                 struct omapfb_color_key *ck)
 {
         struct omapfb_info *ofbi = FB2OFB(fbi);
+        struct omapfb2_device *fbdev = ofbi->fbdev;
         struct omap_overlay_manager *mgr = NULL;
         int r = 0;
         int i;
 
+        omapfb_lock(fbdev);
+
         for (i = 0; i < ofbi->num_overlays; i++) {
                 if (ofbi->overlays[i]->manager) {
                         mgr = ofbi->overlays[i]->manager;
@@ -423,6 +475,8 @@ static int omapfb_get_color_key(struct fb_info *fbi,
 
         *ck = omapfb_color_keys[mgr->id];
 err:
+        omapfb_unlock(fbdev);
+
         return r;
 }
 
@@ -549,8 +603,6 @@ int omapfb_ioctl(struct fb_info *fbi, unsigned int cmd, unsigned long arg)
 
         int r = 0;
 
-        omapfb_lock(fbdev);
-
         switch (cmd) {
         case OMAPFB_SYNC_GFX:
                 DBG("ioctl SYNC_GFX\n");
@@ -856,8 +908,6 @@ int omapfb_ioctl(struct fb_info *fbi, unsigned int cmd, unsigned long arg)
                 r = -EINVAL;
         }
 
-        omapfb_unlock(fbdev);
-
         if (r < 0)
                 DBG("ioctl failed: %d\n", r);