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>
diff --git a/drivers/video/omap2/omapfb/omapfb-ioctl.c b/drivers/video/omap2/omapfb/omapfb-ioctl.c
index dccb158..d30b45d 100644
--- a/drivers/video/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/omap2/omapfb/omapfb-ioctl.c
@@ -85,6 +85,16 @@
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 @@
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 @@
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 @@
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 @@
}
out:
- mutex_unlock(&fbi->mm_lock);
+ atomic_dec(&rg->lock_count);
+ up_write(&rg->lock);
+
return r;
}
@@ -240,12 +272,14 @@
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 @@
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 @@
r = -EINVAL;
}
+ omapfb_unlock(fbdev);
+
return r;
}
@@ -317,10 +357,14 @@
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 @@
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 @@
r = _omapfb_set_color_key(mgr, ck);
err:
+ omapfb_unlock(fbdev);
+
return r;
}
@@ -405,10 +454,13 @@
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 @@
*ck = omapfb_color_keys[mgr->id];
err:
+ omapfb_unlock(fbdev);
+
return r;
}
@@ -549,8 +603,6 @@
int r = 0;
- omapfb_lock(fbdev);
-
switch (cmd) {
case OMAPFB_SYNC_GFX:
DBG("ioctl SYNC_GFX\n");
@@ -856,8 +908,6 @@
r = -EINVAL;
}
- omapfb_unlock(fbdev);
-
if (r < 0)
DBG("ioctl failed: %d\n", r);
diff --git a/drivers/video/omap2/omapfb/omapfb-main.c b/drivers/video/omap2/omapfb/omapfb-main.c
index 948dfb9..ca585ef 100644
--- a/drivers/video/omap2/omapfb/omapfb-main.c
+++ b/drivers/video/omap2/omapfb/omapfb-main.c
@@ -672,6 +672,8 @@
DBG("check_fb_var %d\n", ofbi->id);
+ WARN_ON(!atomic_read(&ofbi->region->lock_count));
+
r = fb_mode_to_dss_mode(var, &mode);
if (r) {
DBG("cannot convert var to omap dss mode\n");
@@ -853,6 +855,8 @@
int rotation = var->rotate;
int i;
+ WARN_ON(!atomic_read(&ofbi->region->lock_count));
+
for (i = 0; i < ofbi->num_overlays; i++) {
if (ovl != ofbi->overlays[i])
continue;
@@ -944,6 +948,8 @@
fill_fb(fbi);
#endif
+ WARN_ON(!atomic_read(&ofbi->region->lock_count));
+
for (i = 0; i < ofbi->num_overlays; i++) {
ovl = ofbi->overlays[i];
@@ -1002,16 +1008,15 @@
static int omapfb_check_var(struct fb_var_screeninfo *var, struct fb_info *fbi)
{
struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
int r;
DBG("check_var(%d)\n", FB2OFB(fbi)->id);
- omapfb_lock(fbdev);
+ omapfb_get_mem_region(ofbi->region);
r = check_fb_var(fbi, var);
- omapfb_unlock(fbdev);
+ omapfb_put_mem_region(ofbi->region);
return r;
}
@@ -1020,12 +1025,11 @@
static int omapfb_set_par(struct fb_info *fbi)
{
struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
int r;
DBG("set_par(%d)\n", FB2OFB(fbi)->id);
- omapfb_lock(fbdev);
+ omapfb_get_mem_region(ofbi->region);
set_fb_fix(fbi);
@@ -1036,7 +1040,7 @@
r = omapfb_apply_changes(fbi, 0);
out:
- omapfb_unlock(fbdev);
+ omapfb_put_mem_region(ofbi->region);
return r;
}
@@ -1045,7 +1049,6 @@
struct fb_info *fbi)
{
struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
struct fb_var_screeninfo new_var;
int r;
@@ -1061,11 +1064,11 @@
fbi->var = new_var;
- omapfb_lock(fbdev);
+ omapfb_get_mem_region(ofbi->region);
r = omapfb_apply_changes(fbi, 0);
- omapfb_unlock(fbdev);
+ omapfb_put_mem_region(ofbi->region);
return r;
}
@@ -1074,14 +1077,18 @@
{
struct omapfb2_mem_region *rg = vma->vm_private_data;
+ omapfb_get_mem_region(rg);
atomic_inc(&rg->map_count);
+ omapfb_put_mem_region(rg);
}
static void mmap_user_close(struct vm_area_struct *vma)
{
struct omapfb2_mem_region *rg = vma->vm_private_data;
+ omapfb_get_mem_region(rg);
atomic_dec(&rg->map_count);
+ omapfb_put_mem_region(rg);
}
static struct vm_operations_struct mmap_user_ops = {
@@ -1105,7 +1112,7 @@
return -EINVAL;
off = vma->vm_pgoff << PAGE_SHIFT;
- rg = ofbi->region;
+ rg = omapfb_get_mem_region(ofbi->region);
start = omapfb_get_region_paddr(ofbi);
len = fix->smem_len;
@@ -1133,9 +1140,13 @@
/* vm_ops.open won't be called for mmap itself. */
atomic_inc(&rg->map_count);
+ omapfb_put_mem_region(rg);
+
return 0;
error:
+ omapfb_put_mem_region(ofbi->region);
+
return r;
}
@@ -1902,6 +1913,7 @@
ofbi->region = &fbdev->regions[i];
ofbi->region->id = i;
+ init_rwsem(&ofbi->region->lock);
/* assign these early, so that fb alloc can use them */
ofbi->rotation_type = def_vrfb ? OMAP_DSS_ROT_VRFB :
@@ -1933,8 +1945,12 @@
/* setup fb_infos */
for (i = 0; i < fbdev->num_fbs; i++) {
struct fb_info *fbi = fbdev->fbs[i];
+ struct omapfb_info *ofbi = FB2OFB(fbi);
+ omapfb_get_mem_region(ofbi->region);
r = omapfb_fb_init(fbdev, fbi);
+ omapfb_put_mem_region(ofbi->region);
+
if (r) {
dev_err(fbdev->dev, "failed to setup fb_info\n");
return r;
@@ -1966,8 +1982,12 @@
for (i = 0; i < fbdev->num_fbs; i++) {
struct fb_info *fbi = fbdev->fbs[i];
+ struct omapfb_info *ofbi = FB2OFB(fbi);
+ omapfb_get_mem_region(ofbi->region);
r = omapfb_apply_changes(fbi, 1);
+ omapfb_put_mem_region(ofbi->region);
+
if (r) {
dev_err(fbdev->dev, "failed to change mode\n");
return r;
diff --git a/drivers/video/omap2/omapfb/omapfb-sysfs.c b/drivers/video/omap2/omapfb/omapfb-sysfs.c
index be5eb07..18fa9e1 100644
--- a/drivers/video/omap2/omapfb/omapfb-sysfs.c
+++ b/drivers/video/omap2/omapfb/omapfb-sysfs.c
@@ -49,7 +49,6 @@
{
struct fb_info *fbi = dev_get_drvdata(dev);
struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
struct omapfb2_mem_region *rg;
int rot_type;
int r;
@@ -63,13 +62,12 @@
if (!lock_fb_info(fbi))
return -ENODEV;
- omapfb_lock(fbdev);
r = 0;
if (rot_type == ofbi->rotation_type)
goto out;
- rg = ofbi->region;
+ rg = omapfb_get_mem_region(ofbi->region);
if (rg->size) {
r = -EBUSY;
@@ -83,8 +81,8 @@
* need to do any further parameter checking at this point.
*/
put_region:
+ omapfb_put_mem_region(rg);
out:
- omapfb_unlock(fbdev);
unlock_fb_info(fbi);
return r ? r : count;
@@ -106,7 +104,6 @@
{
struct fb_info *fbi = dev_get_drvdata(dev);
struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
bool mirror;
int r;
struct fb_var_screeninfo new_var;
@@ -117,10 +114,11 @@
if (!lock_fb_info(fbi))
return -ENODEV;
- omapfb_lock(fbdev);
ofbi->mirror = mirror;
+ omapfb_get_mem_region(ofbi->region);
+
memcpy(&new_var, &fbi->var, sizeof(new_var));
r = check_fb_var(fbi, &new_var);
if (r)
@@ -135,7 +133,8 @@
r = count;
out:
- omapfb_unlock(fbdev);
+ omapfb_put_mem_region(ofbi->region);
+
unlock_fb_info(fbi);
return r;
@@ -274,11 +273,15 @@
DBG("detaching %d\n", ofbi->overlays[i]->id);
+ omapfb_get_mem_region(ofbi->region);
+
omapfb_overlay_enable(ovl, 0);
if (ovl->manager)
ovl->manager->apply(ovl->manager);
+ omapfb_put_mem_region(ofbi->region);
+
for (t = i + 1; t < ofbi->num_overlays; t++) {
ofbi->rotation[t-1] = ofbi->rotation[t];
ofbi->overlays[t-1] = ofbi->overlays[t];
@@ -311,8 +314,12 @@
}
if (added) {
+ omapfb_get_mem_region(ofbi->region);
+
r = omapfb_apply_changes(fbi, 0);
+ omapfb_put_mem_region(ofbi->region);
+
if (r)
goto out;
}
@@ -330,13 +337,11 @@
{
struct fb_info *fbi = dev_get_drvdata(dev);
struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
ssize_t l = 0;
int t;
if (!lock_fb_info(fbi))
return -ENODEV;
- omapfb_lock(fbdev);
for (t = 0; t < ofbi->num_overlays; t++) {
l += snprintf(buf + l, PAGE_SIZE - l, "%s%d",
@@ -345,7 +350,6 @@
l += snprintf(buf + l, PAGE_SIZE - l, "\n");
- omapfb_unlock(fbdev);
unlock_fb_info(fbi);
return l;
@@ -356,7 +360,6 @@
{
struct fb_info *fbi = dev_get_drvdata(dev);
struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
int num_ovls = 0, r, i;
int len;
bool changed = false;
@@ -368,7 +371,6 @@
if (!lock_fb_info(fbi))
return -ENODEV;
- omapfb_lock(fbdev);
if (len > 0) {
char *p = (char *)buf;
@@ -405,7 +407,12 @@
for (i = 0; i < num_ovls; ++i)
ofbi->rotation[i] = rotation[i];
+ omapfb_get_mem_region(ofbi->region);
+
r = omapfb_apply_changes(fbi, 0);
+
+ omapfb_put_mem_region(ofbi->region);
+
if (r)
goto out;
@@ -414,7 +421,6 @@
r = count;
out:
- omapfb_unlock(fbdev);
unlock_fb_info(fbi);
return r;
@@ -425,19 +431,8 @@
{
struct fb_info *fbi = dev_get_drvdata(dev);
struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
- int r;
- if (!lock_fb_info(fbi))
- return -ENODEV;
- omapfb_lock(fbdev);
-
- r = snprintf(buf, PAGE_SIZE, "%lu\n", ofbi->region->size);
-
- omapfb_unlock(fbdev);
- unlock_fb_info(fbi);
-
- return r;
+ return snprintf(buf, PAGE_SIZE, "%lu\n", ofbi->region->size);
}
static ssize_t store_size(struct device *dev, struct device_attribute *attr,
@@ -460,15 +455,15 @@
if (!lock_fb_info(fbi))
return -ENODEV;
- omapfb_lock(fbdev);
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 (atomic_read(&rg->map_count)) {
r = -EBUSY;
goto out;
@@ -501,8 +496,9 @@
r = count;
out:
- mutex_unlock(&fbi->mm_lock);
- omapfb_unlock(fbdev);
+ atomic_dec(&rg->lock_count);
+ up_write(&rg->lock);
+
unlock_fb_info(fbi);
return r;
@@ -513,19 +509,8 @@
{
struct fb_info *fbi = dev_get_drvdata(dev);
struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
- int r;
- if (!lock_fb_info(fbi))
- return -ENODEV;
- omapfb_lock(fbdev);
-
- r = snprintf(buf, PAGE_SIZE, "%0x\n", ofbi->region->paddr);
-
- omapfb_unlock(fbdev);
- unlock_fb_info(fbi);
-
- return r;
+ return snprintf(buf, PAGE_SIZE, "%0x\n", ofbi->region->paddr);
}
static ssize_t show_virt(struct device *dev,
@@ -541,20 +526,11 @@
struct device_attribute *attr, char *buf)
{
struct fb_info *fbi = dev_get_drvdata(dev);
- struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
enum omapfb_update_mode mode;
int r;
- if (!lock_fb_info(fbi))
- return -ENODEV;
- omapfb_lock(fbdev);
-
r = omapfb_get_update_mode(fbi, &mode);
- omapfb_unlock(fbdev);
- unlock_fb_info(fbi);
-
if (r)
return r;
@@ -565,8 +541,6 @@
const char *buf, size_t count)
{
struct fb_info *fbi = dev_get_drvdata(dev);
- struct omapfb_info *ofbi = FB2OFB(fbi);
- struct omapfb2_device *fbdev = ofbi->fbdev;
unsigned mode;
int r;
@@ -574,17 +548,10 @@
if (r)
return r;
- if (!lock_fb_info(fbi))
- return -ENODEV;
- omapfb_lock(fbdev);
-
r = omapfb_set_update_mode(fbi, mode);
if (r)
return r;
- omapfb_unlock(fbdev);
- unlock_fb_info(fbi);
-
return count;
}
diff --git a/drivers/video/omap2/omapfb/omapfb.h b/drivers/video/omap2/omapfb/omapfb.h
index 2b52644..623cd87 100644
--- a/drivers/video/omap2/omapfb/omapfb.h
+++ b/drivers/video/omap2/omapfb/omapfb.h
@@ -62,6 +62,8 @@
bool alloc; /* allocated by the driver */
bool map; /* kernel mapped by the driver */
atomic_t map_count;
+ struct rw_semaphore lock;
+ atomic_t lock_count;
};
/* appended to fb_info */
@@ -189,4 +191,18 @@
return ovl->disable(ovl);
}
+static inline struct omapfb2_mem_region *
+omapfb_get_mem_region(struct omapfb2_mem_region *rg)
+{
+ down_read_nested(&rg->lock, rg->id);
+ atomic_inc(&rg->lock_count);
+ return rg;
+}
+
+static inline void omapfb_put_mem_region(struct omapfb2_mem_region *rg)
+{
+ atomic_dec(&rg->lock_count);
+ up_read(&rg->lock);
+}
+
#endif