Re: [PATCH] drm/bridge/synopsys: dsi: fix initialization sequence
Am Freitag, 18. September 2020, 13:46:53 CEST schrieb Yannick Fertre:
> The current driver calls drm_bridge_add(), to add the dsi bridge
> to the global bridge list, in dw_mipi_dsi_host_attach().
> Thus, it relies on the probing of panel or bridge sub-nodes to
> trigger the execution of dsi host attach() that will, in turn,
> call dw_mipi_dsi_host_attach().
> This causes an incomplete driver initialization if the panel or
> the next bridge is not present as sub-node, e.g. because it is an
> i2c device, thus sub-node of the respective i2c controller.
Actually the drm_of_find_panel_or_bridge() works on of-graph nodes,
so having an remote-port pointing to the i2c/spi/whatever driver
should just work - and no need for the driver to be a subnode itself.
And while my memory is fuzzy, I think I remember Andrzej requesting
only registering the bridge once we know something is connected,
aka when it calls dsi_attach.
Heiko
>
> Move the relevant code from host attach() to probe(), and the
> corresponding code from detach() to remove().
>
> Signed-off-by: Antonio Borneo
> Signed-off-by: Yannick Fertre
> ---
> drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 73 ---
> 1 file changed, 48 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> index 6b268f9445b3..aa74abddc79f 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
> @@ -314,9 +314,7 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host
> *host,
> {
> struct dw_mipi_dsi *dsi = host_to_dsi(host);
> const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
> - struct drm_bridge *bridge;
> - struct drm_panel *panel;
> - int ret;
> + int ret = -ENODEV;
>
> if (device->lanes > dsi->plat_data->max_data_lanes) {
> dev_err(dsi->dev, "the number of data lanes(%u) is too many\n",
> @@ -329,22 +327,6 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host
> *host,
> dsi->format = device->format;
> dsi->mode_flags = device->mode_flags;
>
> - ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0,
> - , );
> - if (ret)
> - return ret;
> -
> - if (panel) {
> - bridge = drm_panel_bridge_add_typed(panel,
> - DRM_MODE_CONNECTOR_DSI);
> - if (IS_ERR(bridge))
> - return PTR_ERR(bridge);
> - }
> -
> - dsi->panel_bridge = bridge;
> -
> - drm_bridge_add(>bridge);
> -
> if (pdata->host_ops && pdata->host_ops->attach) {
> ret = pdata->host_ops->attach(pdata->priv_data, device);
> if (ret < 0)
> @@ -367,10 +349,6 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host
> *host,
> return ret;
> }
>
> - drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);
> -
> - drm_bridge_remove(>bridge);
> -
> return 0;
> }
>
> @@ -1105,6 +1083,9 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
> struct device *dev = >dev;
> struct reset_control *apb_rst;
> struct dw_mipi_dsi *dsi;
> + struct drm_bridge *bridge;
> + struct drm_panel *panel;
> + int i, nb_endpoints;
> int ret;
>
> dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
> @@ -1172,8 +1153,7 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
> ret = mipi_dsi_host_register(>dsi_host);
> if (ret) {
> dev_err(dev, "Failed to register MIPI host: %d\n", ret);
> - dw_mipi_dsi_debugfs_remove(dsi);
> - return ERR_PTR(ret);
> + goto err_pmr_enable;
> }
>
> dsi->bridge.driver_private = dsi;
> @@ -1182,11 +1162,54 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
> dsi->bridge.of_node = pdev->dev.of_node;
> #endif
>
> + /* Get number of endpoints */
> + nb_endpoints = of_graph_get_endpoint_count(pdev->dev.of_node);
> + if (!nb_endpoints) {
> + ret = -ENODEV;
> + goto err_host_reg;
> + }
> +
> + for (i = 1; i < nb_endpoints; i++) {
> + ret = drm_of_find_panel_or_bridge(pdev->dev.of_node, i, 0,
> + , );
> + if (!ret)
> + break;
> + else if (ret == -EPROBE_DEFER)
> + goto err_host_reg;
> + }
> +
> + /* check if an error is returned >> no panel or bridge detected */
> + if (ret)
> + goto err_host_reg;
> +
> + if (panel) {
> + bridge = drm_panel_bridge_add_typed(panel,
> DRM_MODE_CONNECTOR_DSI);
> + if (IS_ERR(bridge)) {
> + ret = PTR_ERR(bridge);
> + goto err_host_reg;
> + }
> + }
> +
> + dsi->panel_bridge = bridge;
> +
> +
[PATCH] drm/bridge/synopsys: dsi: fix initialization sequence
The current driver calls drm_bridge_add(), to add the dsi bridge
to the global bridge list, in dw_mipi_dsi_host_attach().
Thus, it relies on the probing of panel or bridge sub-nodes to
trigger the execution of dsi host attach() that will, in turn,
call dw_mipi_dsi_host_attach().
This causes an incomplete driver initialization if the panel or
the next bridge is not present as sub-node, e.g. because it is an
i2c device, thus sub-node of the respective i2c controller.
Move the relevant code from host attach() to probe(), and the
corresponding code from detach() to remove().
Signed-off-by: Antonio Borneo
Signed-off-by: Yannick Fertre
---
drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 73 ---
1 file changed, 48 insertions(+), 25 deletions(-)
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 6b268f9445b3..aa74abddc79f 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -314,9 +314,7 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host
*host,
{
struct dw_mipi_dsi *dsi = host_to_dsi(host);
const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
- struct drm_bridge *bridge;
- struct drm_panel *panel;
- int ret;
+ int ret = -ENODEV;
if (device->lanes > dsi->plat_data->max_data_lanes) {
dev_err(dsi->dev, "the number of data lanes(%u) is too many\n",
@@ -329,22 +327,6 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host
*host,
dsi->format = device->format;
dsi->mode_flags = device->mode_flags;
- ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0,
- , );
- if (ret)
- return ret;
-
- if (panel) {
- bridge = drm_panel_bridge_add_typed(panel,
- DRM_MODE_CONNECTOR_DSI);
- if (IS_ERR(bridge))
- return PTR_ERR(bridge);
- }
-
- dsi->panel_bridge = bridge;
-
- drm_bridge_add(>bridge);
-
if (pdata->host_ops && pdata->host_ops->attach) {
ret = pdata->host_ops->attach(pdata->priv_data, device);
if (ret < 0)
@@ -367,10 +349,6 @@ static int dw_mipi_dsi_host_detach(struct mipi_dsi_host
*host,
return ret;
}
- drm_of_panel_bridge_remove(host->dev->of_node, 1, 0);
-
- drm_bridge_remove(>bridge);
-
return 0;
}
@@ -1105,6 +1083,9 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
struct device *dev = >dev;
struct reset_control *apb_rst;
struct dw_mipi_dsi *dsi;
+ struct drm_bridge *bridge;
+ struct drm_panel *panel;
+ int i, nb_endpoints;
int ret;
dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
@@ -1172,8 +1153,7 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
ret = mipi_dsi_host_register(>dsi_host);
if (ret) {
dev_err(dev, "Failed to register MIPI host: %d\n", ret);
- dw_mipi_dsi_debugfs_remove(dsi);
- return ERR_PTR(ret);
+ goto err_pmr_enable;
}
dsi->bridge.driver_private = dsi;
@@ -1182,11 +1162,54 @@ __dw_mipi_dsi_probe(struct platform_device *pdev,
dsi->bridge.of_node = pdev->dev.of_node;
#endif
+ /* Get number of endpoints */
+ nb_endpoints = of_graph_get_endpoint_count(pdev->dev.of_node);
+ if (!nb_endpoints) {
+ ret = -ENODEV;
+ goto err_host_reg;
+ }
+
+ for (i = 1; i < nb_endpoints; i++) {
+ ret = drm_of_find_panel_or_bridge(pdev->dev.of_node, i, 0,
+ , );
+ if (!ret)
+ break;
+ else if (ret == -EPROBE_DEFER)
+ goto err_host_reg;
+ }
+
+ /* check if an error is returned >> no panel or bridge detected */
+ if (ret)
+ goto err_host_reg;
+
+ if (panel) {
+ bridge = drm_panel_bridge_add_typed(panel,
DRM_MODE_CONNECTOR_DSI);
+ if (IS_ERR(bridge)) {
+ ret = PTR_ERR(bridge);
+ goto err_host_reg;
+ }
+ }
+
+ dsi->panel_bridge = bridge;
+
+ drm_bridge_add(>bridge);
+
return dsi;
+
+err_host_reg:
+ mipi_dsi_host_unregister(>dsi_host);
+
+err_pmr_enable:
+ pm_runtime_disable(dev);
+ dw_mipi_dsi_debugfs_remove(dsi);
+
+ return ERR_PTR(ret);
}
static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
{
+ drm_bridge_remove(>bridge);
+ drm_panel_bridge_remove(dsi->panel_bridge);
mipi_dsi_host_unregister(>dsi_host);
pm_runtime_disable(dsi->dev);
--
2.17.1
