[PATCH 15/17] drm/imx: imx-ldb: split encoder and decoder states
Marco Felsch
m.felsch at pengutronix.de
Thu Feb 27 16:21:23 UTC 2020
The race condition reported by [1] applies to the all drm-imx
subcomponent drivers which implements an encoder:connector combination.
The goal is to switch from the devres-kmalloc and the component
framework to a 'normal' kmalloc and the drm framework to release the
memory resources. So all acquired memory resoruces are freed by a
drm_mode_config_cleanup() call and the ->destroy() callbacks. For this
purpose we need to slit the drm_encoder and the drm_connector state.
[1] https://www.spinics.net/lists/dri-devel/msg189388.html
Signed-off-by: Marco Felsch <m.felsch at pengutronix.de>
---
drivers/gpu/drm/imx/imx-ldb.c | 106 +++++++++++++++++++++-------------
1 file changed, 66 insertions(+), 40 deletions(-)
diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c
index 5ef9fcb9ae94..0e5a3c84df10 100644
--- a/drivers/gpu/drm/imx/imx-ldb.c
+++ b/drivers/gpu/drm/imx/imx-ldb.c
@@ -50,7 +50,6 @@ struct imx_ldb;
struct imx_ldb_channel {
struct imx_ldb *ldb;
- struct drm_connector connector;
struct drm_encoder encoder;
/* Defines what is connected to the ldb, only one at a time */
@@ -58,19 +57,26 @@ struct imx_ldb_channel {
struct drm_bridge *bridge;
struct device_node *child;
- struct i2c_adapter *ddc;
int chno;
+ u32 bus_format;
+ u32 bus_flags;
+};
+
+struct imx_ldb_connector {
+ struct imx_ldb_channel *ldb_channel;
+ struct drm_connector connector;
+
+ struct i2c_adapter *ddc;
void *edid;
int edid_len;
+
struct drm_display_mode mode;
int mode_valid;
- u32 bus_format;
- u32 bus_flags;
};
-static inline struct imx_ldb_channel *con_to_imx_ldb_ch(struct drm_connector *c)
+static inline struct imx_ldb_connector *con_to_imx_ldb_con(struct drm_connector *c)
{
- return container_of(c, struct imx_ldb_channel, connector);
+ return container_of(c, struct imx_ldb_connector, connector);
}
static inline struct imx_ldb_channel *enc_to_imx_ldb_ch(struct drm_encoder *e)
@@ -126,31 +132,41 @@ static void imx_ldb_ch_set_bus_format(struct imx_ldb_channel *imx_ldb_ch,
}
}
+static void imx_ldb_connector_destroy(struct drm_connector *connector)
+{
+ struct imx_ldb_connector *imx_ldb_con = con_to_imx_ldb_con(connector);
+
+ imx_drm_connector_destroy(connector);
+ i2c_put_adapter(imx_ldb_con->ddc);
+ /* avoid dangling pointers */
+ imx_ldb_con->ldb_channel = NULL;
+}
+
static int imx_ldb_connector_get_modes(struct drm_connector *connector)
{
- struct imx_ldb_channel *imx_ldb_ch = con_to_imx_ldb_ch(connector);
+ struct imx_ldb_connector *imx_ldb_con = con_to_imx_ldb_con(connector);
+ struct imx_ldb_channel *imx_ldb_ch = imx_ldb_con->ldb_channel;
int num_modes;
num_modes = drm_panel_get_modes(imx_ldb_ch->panel, connector);
if (num_modes > 0)
return num_modes;
- if (!imx_ldb_ch->edid && imx_ldb_ch->ddc)
- imx_ldb_ch->edid = drm_get_edid(connector, imx_ldb_ch->ddc);
+ if (!imx_ldb_con->edid && imx_ldb_con->ddc)
+ imx_ldb_con->edid = drm_get_edid(connector, imx_ldb_con->ddc);
- if (imx_ldb_ch->edid) {
- drm_connector_update_edid_property(connector,
- imx_ldb_ch->edid);
- num_modes = drm_add_edid_modes(connector, imx_ldb_ch->edid);
+ if (imx_ldb_con->edid) {
+ drm_connector_update_edid_property(connector, imx_ldb_con->edid);
+ num_modes = drm_add_edid_modes(connector, imx_ldb_con->edid);
}
- if (imx_ldb_ch->mode_valid) {
+ if (imx_ldb_con->mode_valid) {
struct drm_display_mode *mode;
mode = drm_mode_create(connector->dev);
if (!mode)
return -EINVAL;
- drm_mode_copy(mode, &imx_ldb_ch->mode);
+ drm_mode_copy(mode, &imx_ldb_con->mode);
mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
drm_mode_probed_add(connector, mode);
num_modes++;
@@ -166,7 +182,8 @@ static void imx_ldb_encoder_destroy(struct drm_encoder *encoder)
if (channel->panel)
drm_panel_detach(channel->panel);
drm_encoder_cleanup(encoder);
- i2c_put_adapter(channel->ddc);
+ /* avoid dangling pointers */
+ channel->ldb = NULL;
}
static void imx_ldb_set_clock(struct imx_ldb *ldb, int mux, int chno,
@@ -388,7 +405,7 @@ static int imx_ldb_encoder_atomic_check(struct drm_encoder *encoder,
static const struct drm_connector_funcs imx_ldb_connector_funcs = {
.fill_modes = drm_helper_probe_single_connector_modes,
- .destroy = imx_drm_connector_destroy,
+ .destroy = imx_ldb_connector_destroy,
.reset = drm_atomic_helper_connector_reset,
.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
@@ -424,11 +441,13 @@ static int imx_ldb_get_clk(struct imx_ldb *ldb, int chno)
return PTR_ERR_OR_ZERO(ldb->clk_pll[chno]);
}
-static int imx_ldb_register(struct drm_device *drm,
- struct imx_ldb_channel *imx_ldb_ch)
+static int imx_ldb_register_channel(struct drm_device *drm,
+ struct imx_ldb_channel *imx_ldb_ch,
+ struct imx_ldb_connector *imx_ldb_con)
{
struct imx_ldb *ldb = imx_ldb_ch->ldb;
struct drm_encoder *encoder = &imx_ldb_ch->encoder;
+ struct drm_connector *connector = &imx_ldb_con->connector;
int ret;
ret = imx_drm_encoder_parse_of(drm, encoder, imx_ldb_ch->child);
@@ -450,8 +469,7 @@ static int imx_ldb_register(struct drm_device *drm,
DRM_MODE_ENCODER_LVDS, NULL);
if (imx_ldb_ch->bridge) {
- ret = drm_bridge_attach(&imx_ldb_ch->encoder,
- imx_ldb_ch->bridge, NULL);
+ ret = drm_bridge_attach(encoder, imx_ldb_ch->bridge, NULL);
if (ret) {
DRM_ERROR("Failed to initialize bridge with drm\n");
return ret;
@@ -463,18 +481,17 @@ static int imx_ldb_register(struct drm_device *drm,
* historical reasons, the ldb driver can also work without
* a panel.
*/
- drm_connector_helper_add(&imx_ldb_ch->connector,
- &imx_ldb_connector_helper_funcs);
- drm_connector_init_with_ddc(drm, &imx_ldb_ch->connector,
+ drm_connector_helper_add(connector,
+ &imx_ldb_connector_helper_funcs);
+ drm_connector_init_with_ddc(drm, connector,
&imx_ldb_connector_funcs,
DRM_MODE_CONNECTOR_LVDS,
- imx_ldb_ch->ddc);
- drm_connector_attach_encoder(&imx_ldb_ch->connector, encoder);
+ imx_ldb_con->ddc);
+ drm_connector_attach_encoder(connector, encoder);
}
if (imx_ldb_ch->panel) {
- ret = drm_panel_attach(imx_ldb_ch->panel,
- &imx_ldb_ch->connector);
+ ret = drm_panel_attach(imx_ldb_ch->panel, connector);
if (ret)
return ret;
}
@@ -518,7 +535,9 @@ static u32 of_get_bus_format(struct device *dev, struct device_node *np)
}
static int imx_ldb_panel_ddc(struct device *dev,
- struct imx_ldb_channel *channel, struct device_node *child)
+ struct imx_ldb_channel *channel,
+ struct imx_ldb_connector *connector,
+ struct device_node *child)
{
struct device_node *ddc_node;
const u8 *edidp;
@@ -526,32 +545,32 @@ static int imx_ldb_panel_ddc(struct device *dev,
ddc_node = of_parse_phandle(child, "ddc-i2c-bus", 0);
if (ddc_node) {
- channel->ddc = of_find_i2c_adapter_by_node(ddc_node);
+ connector->ddc = of_find_i2c_adapter_by_node(ddc_node);
of_node_put(ddc_node);
- if (!channel->ddc) {
+ if (!connector->ddc) {
dev_warn(dev, "failed to get ddc i2c adapter\n");
return -EPROBE_DEFER;
}
}
- if (!channel->ddc) {
+ if (!connector->ddc) {
/* if no DDC available, fallback to hardcoded EDID */
dev_dbg(dev, "no ddc available\n");
edidp = of_get_property(child, "edid",
- &channel->edid_len);
+ &connector->edid_len);
if (edidp) {
- channel->edid = devm_kmemdup(dev, edidp,
- channel->edid_len,
- GFP_KERNEL);
+ connector->edid = devm_kmemdup(dev, edidp,
+ connector->edid_len,
+ GFP_KERNEL);
} else if (!channel->panel) {
/* fallback to display-timings node */
ret = of_get_drm_display_mode(child,
- &channel->mode,
+ &connector->mode,
&channel->bus_flags,
OF_USE_NATIVE_MODE);
if (!ret)
- channel->mode_valid = 1;
+ connector->mode_valid = 1;
}
}
return 0;
@@ -569,6 +588,7 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
for_each_child_of_node(np, child) {
struct imx_ldb_channel *channel;
+ struct imx_ldb_connector *connector;
int bus_format;
ret = of_property_read_u32(child, "reg", &i);
@@ -604,9 +624,15 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
/* panel ddc only if there is no bridge */
if (!channel->bridge) {
- ret = imx_ldb_panel_ddc(dev, channel, child);
+ connector = devm_kzalloc(dev, sizeof(*connector), GFP_KERNEL);
+ if (!connector)
+ return -ENOMEM;
+
+ ret = imx_ldb_panel_ddc(dev, channel, connector, child);
if (ret)
goto free_child;
+
+ connector->ldb_channel = channel;
}
bus_format = of_get_bus_format(dev, child);
@@ -628,7 +654,7 @@ static int imx_ldb_bind(struct device *dev, struct device *master, void *data)
channel->bus_format = bus_format;
channel->child = child;
- ret = imx_ldb_register(drm, channel);
+ ret = imx_ldb_register_channel(drm, channel, connector);
if (ret) {
channel->child = NULL;
goto free_child;
--
2.20.1
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