smatch reports:
drivers/gpu/drm/omapdrm/dss/base.c:176 omapdss_device_disconnect() error: we previously assumed 'src' could be null (see line 169)
This code is mostly from a time when omapdrm had its own display device
model. I can't honestly remember the details, and I don't think it's
worth digging in deeply into that for a legacy driver.
However, it looks like we only call omapdss_device_disconnect() and
omapdss_device_connect() with NULL as the src parameter. We can thus
drop the src parameter from both functions, and fix the smatch warning.
I don't think omapdss_device_disconnect() ever gets NULL for the dst
parameter (if it did, we'd crash soon after returning from the
function), but I have kept the !dst check, just in case, but I added a
WARN_ON() there.
Also, if the dst parameter can be NULL, we can't always get the struct
dss_device pointer from dst->dss (which is only used for a debug print).
To make sure we can't hit that issue, do it similarly to the
omapdss_device_connect() function: add 'struct dss_device *dss' as the
first parameter, so that we always have it regardless of the dst.
Fixes: 79107f274b2f ("drm/omap: Add support for drm_bridge")
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/omapdrm/dss/base.c | 25 ++++++-------------------
drivers/gpu/drm/omapdrm/dss/omapdss.h | 3 +--
drivers/gpu/drm/omapdrm/omap_drv.c | 4 ++--
3 files changed, 9 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/omapdrm/dss/base.c b/drivers/gpu/drm/omapdrm/dss/base.c
index 050ca7eafac5..556e0f9026be 100644
--- a/drivers/gpu/drm/omapdrm/dss/base.c
+++ b/drivers/gpu/drm/omapdrm/dss/base.c
@@ -139,21 +139,13 @@ static bool omapdss_device_is_connected(struct omap_dss_device *dssdev)
}
int omapdss_device_connect(struct dss_device *dss,
- struct omap_dss_device *src,
struct omap_dss_device *dst)
{
- dev_dbg(&dss->pdev->dev, "connect(%s, %s)\n",
- src ? dev_name(src->dev) : "NULL",
+ dev_dbg(&dss->pdev->dev, "connect(%s)\n",
dst ? dev_name(dst->dev) : "NULL");
- if (!dst) {
- /*
- * The destination is NULL when the source is connected to a
- * bridge instead of a DSS device. Stop here, we will attach
- * the bridge later when we will have a DRM encoder.
- */
- return src && src->bridge ? 0 : -EINVAL;
- }
+ if (!dst)
+ return -EINVAL;
if (omapdss_device_is_connected(dst))
return -EBUSY;
@@ -163,19 +155,14 @@ int omapdss_device_connect(struct dss_device *dss,
return 0;
}
-void omapdss_device_disconnect(struct omap_dss_device *src,
+void omapdss_device_disconnect(struct dss_device *dss,
struct omap_dss_device *dst)
{
- struct dss_device *dss = src ? src->dss : dst->dss;
-
- dev_dbg(&dss->pdev->dev, "disconnect(%s, %s)\n",
- src ? dev_name(src->dev) : "NULL",
+ dev_dbg(&dss->pdev->dev, "disconnect(%s)\n",
dst ? dev_name(dst->dev) : "NULL");
- if (!dst) {
- WARN_ON(!src->bridge);
+ if (WARN_ON(!dst))
return;
- }
if (!dst->id && !omapdss_device_is_connected(dst)) {
WARN_ON(1);
diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h
index 040d5a3e33d6..4c22c09c93d5 100644
--- a/drivers/gpu/drm/omapdrm/dss/omapdss.h
+++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h
@@ -242,9 +242,8 @@ struct omap_dss_device *omapdss_device_get(struct omap_dss_device *dssdev);
void omapdss_device_put(struct omap_dss_device *dssdev);
struct omap_dss_device *omapdss_find_device_by_node(struct device_node *node);
int omapdss_device_connect(struct dss_device *dss,
- struct omap_dss_device *src,
struct omap_dss_device *dst);
-void omapdss_device_disconnect(struct omap_dss_device *src,
+void omapdss_device_disconnect(struct dss_device *dss,
struct omap_dss_device *dst);
int omap_dss_get_num_overlay_managers(void);
diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
index 6598c9c08ba1..d80d24fce79f 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.c
+++ b/drivers/gpu/drm/omapdrm/omap_drv.c
@@ -307,7 +307,7 @@ static void omap_disconnect_pipelines(struct drm_device *ddev)
for (i = 0; i < priv->num_pipes; i++) {
struct omap_drm_pipeline *pipe = &priv->pipes[i];
- omapdss_device_disconnect(NULL, pipe->output);
+ omapdss_device_disconnect(priv->dss, pipe->output);
omapdss_device_put(pipe->output);
pipe->output = NULL;
@@ -325,7 +325,7 @@ static int omap_connect_pipelines(struct drm_device *ddev)
int r;
for_each_dss_output(output) {
- r = omapdss_device_connect(priv->dss, NULL, output);
+ r = omapdss_device_connect(priv->dss, output);
if (r == -EPROBE_DEFER) {
omapdss_device_put(output);
return r;
--
2.43.0
