From: ville.syrjala@nokia.com
To: Tomi Valkeinen <tomi.valkeinen@nokia.com>
Cc: "Imre Deak" <imre.deak@nokia.com>,
linux-fbdev@vger.kernel.org, linux-omap@vger.kernel.org,
"Ville Syrjälä" <ville.syrjala@nokia.com>
Subject: [PATCH v4 7/8] DSS2: OMAPFB: Make lockdep happy
Date: Wed, 17 Mar 2010 22:46:22 +0000 [thread overview]
Message-ID: <1268865983-16270-8-git-send-email-ville.syrjala@nokia.com> (raw)
In-Reply-To: <1268865983-16270-1-git-send-email-ville.syrjala@nokia.com>
From: Ville Syrj채l채 <ville.syrjala@nokia.com>
When more than one memory region needs to be lockd at the same time use
the memory region id to fix the order in which the locks are taken. Also
one needs to use the _nested() versions of the locking primitives. The
memory region id can serve as the lock class there as well.
Signed-off-by: Ville Syrj채l채 <ville.syrjala@nokia.com>
---
drivers/video/omap2/omapfb/omapfb-ioctl.c | 45 ++++++++++++++++++++++-------
drivers/video/omap2/omapfb/omapfb-sysfs.c | 2 +-
drivers/video/omap2/omapfb/omapfb.h | 2 +-
3 files changed, 36 insertions(+), 13 deletions(-)
diff --git a/drivers/video/omap2/omapfb/omapfb-ioctl.c b/drivers/video/omap2/omapfb/omapfb-ioctl.c
index 4d5e5af..a3681da 100644
--- a/drivers/video/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/omap2/omapfb/omapfb-ioctl.c
@@ -55,7 +55,7 @@ static struct omapfb2_mem_region *get_mem_region(struct omapfb_info *ofbi,
if (mem_idx >= fbdev->num_fbs)
return NULL;
- return omapfb_get_mem_region(&fbdev->regions[mem_idx]);
+ return &fbdev->regions[mem_idx];
}
static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
@@ -77,20 +77,30 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
/* XXX uses only the first overlay */
ovl = ofbi->overlays[0];
- old_rg = omapfb_get_mem_region(ofbi->region);
+ old_rg = ofbi->region;
new_rg = get_mem_region(ofbi, pi->mem_idx);
if (!new_rg) {
r = -EINVAL;
- goto put_old;
+ 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
* until it's reallocated.
*/
r = -EINVAL;
- goto put_new;
+ goto put_mem;
}
ovl->get_overlay_info(ovl, &old_info);
@@ -135,8 +145,15 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
if (ovl->manager)
ovl->manager->apply(ovl->manager);
- omapfb_put_mem_region(new_rg);
- omapfb_put_mem_region(old_rg);
+ /* 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;
@@ -147,10 +164,16 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
}
ovl->set_overlay_info(ovl, &old_info);
- put_new:
- omapfb_put_mem_region(new_rg);
- put_old:
- omapfb_put_mem_region(old_rg);
+ 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");
@@ -198,7 +221,7 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
rg = ofbi->region;
- down_write(&rg->lock);
+ down_write_nested(&rg->lock, rg->id);
if (atomic_read(&rg->map_count)) {
r = -EBUSY;
diff --git a/drivers/video/omap2/omapfb/omapfb-sysfs.c b/drivers/video/omap2/omapfb/omapfb-sysfs.c
index aa22f7b..1b7cf57 100644
--- a/drivers/video/omap2/omapfb/omapfb-sysfs.c
+++ b/drivers/video/omap2/omapfb/omapfb-sysfs.c
@@ -445,7 +445,7 @@ static ssize_t store_size(struct device *dev, struct device_attribute *attr,
rg = ofbi->region;
- down_write(&rg->lock);
+ down_write_nested(&rg->lock, rg->id);
if (atomic_read(&rg->map_count)) {
r = -EBUSY;
diff --git a/drivers/video/omap2/omapfb/omapfb.h b/drivers/video/omap2/omapfb/omapfb.h
index 195a760..676b55d 100644
--- a/drivers/video/omap2/omapfb/omapfb.h
+++ b/drivers/video/omap2/omapfb/omapfb.h
@@ -165,7 +165,7 @@ static inline int omapfb_overlay_enable(struct omap_overlay *ovl,
static inline struct omapfb2_mem_region *
omapfb_get_mem_region(struct omapfb2_mem_region *rg)
{
- down_read(&rg->lock);
+ down_read_nested(&rg->lock, rg->id);
return rg;
}
--
1.6.4.4
--
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WARNING: multiple messages have this Message-ID (diff)
From: ville.syrjala@nokia.com
To: Tomi Valkeinen <tomi.valkeinen@nokia.com>
Cc: "Imre Deak" <imre.deak@nokia.com>,
linux-fbdev@vger.kernel.org, linux-omap@vger.kernel.org,
"Ville Syrjälä" <ville.syrjala@nokia.com>
Subject: [PATCH v4 7/8] DSS2: OMAPFB: Make lockdep happy
Date: Thu, 18 Mar 2010 00:46:22 +0200 [thread overview]
Message-ID: <1268865983-16270-8-git-send-email-ville.syrjala@nokia.com> (raw)
In-Reply-To: <1268865983-16270-1-git-send-email-ville.syrjala@nokia.com>
From: Ville Syrjälä <ville.syrjala@nokia.com>
When more than one memory region needs to be lockd at the same time use
the memory region id to fix the order in which the locks are taken. Also
one needs to use the _nested() versions of the locking primitives. The
memory region id can serve as the lock class there as well.
Signed-off-by: Ville Syrjälä <ville.syrjala@nokia.com>
---
drivers/video/omap2/omapfb/omapfb-ioctl.c | 45 ++++++++++++++++++++++-------
drivers/video/omap2/omapfb/omapfb-sysfs.c | 2 +-
drivers/video/omap2/omapfb/omapfb.h | 2 +-
3 files changed, 36 insertions(+), 13 deletions(-)
diff --git a/drivers/video/omap2/omapfb/omapfb-ioctl.c b/drivers/video/omap2/omapfb/omapfb-ioctl.c
index 4d5e5af..a3681da 100644
--- a/drivers/video/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/omap2/omapfb/omapfb-ioctl.c
@@ -55,7 +55,7 @@ static struct omapfb2_mem_region *get_mem_region(struct omapfb_info *ofbi,
if (mem_idx >= fbdev->num_fbs)
return NULL;
- return omapfb_get_mem_region(&fbdev->regions[mem_idx]);
+ return &fbdev->regions[mem_idx];
}
static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
@@ -77,20 +77,30 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
/* XXX uses only the first overlay */
ovl = ofbi->overlays[0];
- old_rg = omapfb_get_mem_region(ofbi->region);
+ old_rg = ofbi->region;
new_rg = get_mem_region(ofbi, pi->mem_idx);
if (!new_rg) {
r = -EINVAL;
- goto put_old;
+ 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
* until it's reallocated.
*/
r = -EINVAL;
- goto put_new;
+ goto put_mem;
}
ovl->get_overlay_info(ovl, &old_info);
@@ -135,8 +145,15 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
if (ovl->manager)
ovl->manager->apply(ovl->manager);
- omapfb_put_mem_region(new_rg);
- omapfb_put_mem_region(old_rg);
+ /* 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;
@@ -147,10 +164,16 @@ static int omapfb_setup_plane(struct fb_info *fbi, struct omapfb_plane_info *pi)
}
ovl->set_overlay_info(ovl, &old_info);
- put_new:
- omapfb_put_mem_region(new_rg);
- put_old:
- omapfb_put_mem_region(old_rg);
+ 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");
@@ -198,7 +221,7 @@ static int omapfb_setup_mem(struct fb_info *fbi, struct omapfb_mem_info *mi)
rg = ofbi->region;
- down_write(&rg->lock);
+ down_write_nested(&rg->lock, rg->id);
if (atomic_read(&rg->map_count)) {
r = -EBUSY;
diff --git a/drivers/video/omap2/omapfb/omapfb-sysfs.c b/drivers/video/omap2/omapfb/omapfb-sysfs.c
index aa22f7b..1b7cf57 100644
--- a/drivers/video/omap2/omapfb/omapfb-sysfs.c
+++ b/drivers/video/omap2/omapfb/omapfb-sysfs.c
@@ -445,7 +445,7 @@ static ssize_t store_size(struct device *dev, struct device_attribute *attr,
rg = ofbi->region;
- down_write(&rg->lock);
+ down_write_nested(&rg->lock, rg->id);
if (atomic_read(&rg->map_count)) {
r = -EBUSY;
diff --git a/drivers/video/omap2/omapfb/omapfb.h b/drivers/video/omap2/omapfb/omapfb.h
index 195a760..676b55d 100644
--- a/drivers/video/omap2/omapfb/omapfb.h
+++ b/drivers/video/omap2/omapfb/omapfb.h
@@ -165,7 +165,7 @@ static inline int omapfb_overlay_enable(struct omap_overlay *ovl,
static inline struct omapfb2_mem_region *
omapfb_get_mem_region(struct omapfb2_mem_region *rg)
{
- down_read(&rg->lock);
+ down_read_nested(&rg->lock, rg->id);
return rg;
}
--
1.6.4.4
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next prev parent reply other threads:[~2010-03-17 22:46 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-17 22:46 omapfb mem_idx patchset ville.syrjala
2010-03-17 22:46 ` ville.syrjala
2010-03-17 22:46 ` [PATCH v4 1/8] DSS2: OMAPFB: Refactor overlay address calculations ville.syrjala
2010-03-17 22:46 ` ville.syrjala
2010-03-17 22:46 ` [PATCH v4 2/8] DSS2: OMAPFB: Check var even if there isn't memory ville.syrjala
2010-03-17 22:46 ` ville.syrjala
2010-03-17 22:46 ` [PATCH v4 3/8] DSS2: OMAPFB: Skip unnecessary set_overlay_info() ville.syrjala
2010-03-17 22:46 ` ville.syrjala
2010-03-17 22:46 ` [PATCH v4 4/8] DSS2: OMAPFB: Add support for switching memory regions ville.syrjala
2010-03-17 22:46 ` ville.syrjala
2010-03-17 22:46 ` [PATCH v4 5/8] DSS2: OMAPFB: Add locking for " ville.syrjala
2010-03-17 22:46 ` ville.syrjala
2010-03-17 22:46 ` [PATCH v4 6/8] DSS2: OMAPFB: Convert the memory region locking to rwsem ville.syrjala
2010-03-17 22:46 ` ville.syrjala
2010-03-17 22:46 ` ville.syrjala [this message]
2010-03-17 22:46 ` [PATCH v4 7/8] DSS2: OMAPFB: Make lockdep happy ville.syrjala
2010-03-17 22:46 ` [PATCH v4 8/8] DSS2: OMAPFB: Add some locking debug checks ville.syrjala
2010-03-17 22:46 ` ville.syrjala
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