Hi, Angelo:
AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com 於 2022年1月31日 週一 下午4:55寫道：
DRM bridge drivers are now attaching their DSI device at probe time, which requires us to register our DSI host in order to let the bridge to probe: this recently started producing an endless -EPROBE_DEFER loop on some machines that are using external bridges, like the parade-ps8640, found on the ACER Chromebook R13.
Now that the DSI hosts/devices probe sequence is documented, we can do adjustments to the mtk_dsi driver as to both fix now and make sure to avoid this situation in the future: for this, following what is documented in drm_bridge.c, move the mtk_dsi component_add() to the mtk_dsi_ops.attach callback and delete it in the detach callback; keeping in mind that we are registering a drm_bridge for our DSI, which is only used/attached if the DSI Host is bound, it wouldn't make sense to keep adding our bridge at probe time (as it would be useless to have it if mtk_dsi_ops.attach() fails!), so also move that one to the dsi host attach function (and remove it in detach).
Applied to mediatek-drm-fixes[1], thanks.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?...
Regards, Chun-Kuang.
Cc: stable@vger.kernel.org # 5.15.x Signed-off-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Reviewed-by: Andrzej Hajda andrzej.hajda@intel.com Reviewed-by: Jagan Teki jagan@amarulasolutions.com
drivers/gpu/drm/mediatek/mtk_dsi.c | 167 +++++++++++++++-------------- 1 file changed, 84 insertions(+), 83 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 5d90d2eb0019..bced4c7d668e 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -786,18 +786,101 @@ void mtk_dsi_ddp_stop(struct device *dev) mtk_dsi_poweroff(dsi); }
+static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi) +{
int ret;ret = drm_simple_encoder_init(drm, &dsi->encoder,DRM_MODE_ENCODER_DSI);if (ret) {DRM_ERROR("Failed to encoder init to drm\n");return ret;}dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev);ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,DRM_BRIDGE_ATTACH_NO_CONNECTOR);if (ret)goto err_cleanup_encoder;dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);if (IS_ERR(dsi->connector)) {DRM_ERROR("Unable to create bridge connector\n");ret = PTR_ERR(dsi->connector);goto err_cleanup_encoder;}drm_connector_attach_encoder(dsi->connector, &dsi->encoder);return 0;+err_cleanup_encoder:
drm_encoder_cleanup(&dsi->encoder);return ret;+}
+static int mtk_dsi_bind(struct device *dev, struct device *master, void *data) +{
int ret;struct drm_device *drm = data;struct mtk_dsi *dsi = dev_get_drvdata(dev);ret = mtk_dsi_encoder_init(drm, dsi);if (ret)return ret;return device_reset_optional(dev);+}
+static void mtk_dsi_unbind(struct device *dev, struct device *master,
void *data)+{
struct mtk_dsi *dsi = dev_get_drvdata(dev);drm_encoder_cleanup(&dsi->encoder);+}
+static const struct component_ops mtk_dsi_component_ops = {
.bind = mtk_dsi_bind,.unbind = mtk_dsi_unbind,+};
static int mtk_dsi_host_attach(struct mipi_dsi_host *host, struct mipi_dsi_device *device) { struct mtk_dsi *dsi = host_to_dsi(host);
struct device *dev = host->dev;int ret; dsi->lanes = device->lanes; dsi->format = device->format; dsi->mode_flags = device->mode_flags;dsi->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 0, 0);if (IS_ERR(dsi->next_bridge))return PTR_ERR(dsi->next_bridge);drm_bridge_add(&dsi->bridge);ret = component_add(host->dev, &mtk_dsi_component_ops);if (ret) {DRM_ERROR("failed to add dsi_host component: %d\n", ret);drm_bridge_remove(&dsi->bridge);return ret;} return 0;}
+static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
struct mipi_dsi_device *device)+{
struct mtk_dsi *dsi = host_to_dsi(host);component_del(host->dev, &mtk_dsi_component_ops);drm_bridge_remove(&dsi->bridge);return 0;+}
static void mtk_dsi_wait_for_idle(struct mtk_dsi *dsi) { int ret; @@ -938,73 +1021,14 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
static const struct mipi_dsi_host_ops mtk_dsi_ops = { .attach = mtk_dsi_host_attach,
.detach = mtk_dsi_host_detach, .transfer = mtk_dsi_host_transfer,};
-static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi) -{
int ret;ret = drm_simple_encoder_init(drm, &dsi->encoder,DRM_MODE_ENCODER_DSI);if (ret) {DRM_ERROR("Failed to encoder init to drm\n");return ret;}dsi->encoder.possible_crtcs = mtk_drm_find_possible_crtc_by_comp(drm, dsi->host.dev);ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,DRM_BRIDGE_ATTACH_NO_CONNECTOR);if (ret)goto err_cleanup_encoder;dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);if (IS_ERR(dsi->connector)) {DRM_ERROR("Unable to create bridge connector\n");ret = PTR_ERR(dsi->connector);goto err_cleanup_encoder;}drm_connector_attach_encoder(dsi->connector, &dsi->encoder);return 0;-err_cleanup_encoder:
drm_encoder_cleanup(&dsi->encoder);return ret;-}
-static int mtk_dsi_bind(struct device *dev, struct device *master, void *data) -{
int ret;struct drm_device *drm = data;struct mtk_dsi *dsi = dev_get_drvdata(dev);ret = mtk_dsi_encoder_init(drm, dsi);if (ret)return ret;return device_reset_optional(dev);-}
-static void mtk_dsi_unbind(struct device *dev, struct device *master,
void *data)-{
struct mtk_dsi *dsi = dev_get_drvdata(dev);drm_encoder_cleanup(&dsi->encoder);-}
-static const struct component_ops mtk_dsi_component_ops = {
.bind = mtk_dsi_bind,.unbind = mtk_dsi_unbind,-};
static int mtk_dsi_probe(struct platform_device *pdev) { struct mtk_dsi *dsi; struct device *dev = &pdev->dev;
struct drm_panel *panel; struct resource *regs; int irq_num; int ret;@@ -1021,19 +1045,6 @@ static int mtk_dsi_probe(struct platform_device *pdev) return ret; }
ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,&panel, &dsi->next_bridge);if (ret)goto err_unregister_host;if (panel) {dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel);if (IS_ERR(dsi->next_bridge)) {ret = PTR_ERR(dsi->next_bridge);goto err_unregister_host;}}dsi->driver_data = of_device_get_match_data(dev); dsi->engine_clk = devm_clk_get(dev, "engine");@@ -1098,14 +1109,6 @@ static int mtk_dsi_probe(struct platform_device *pdev) dsi->bridge.of_node = dev->of_node; dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
drm_bridge_add(&dsi->bridge);ret = component_add(&pdev->dev, &mtk_dsi_component_ops);if (ret) {dev_err(&pdev->dev, "failed to add component: %d\n", ret);goto err_unregister_host;}return 0;err_unregister_host: @@ -1118,8 +1121,6 @@ static int mtk_dsi_remove(struct platform_device *pdev) struct mtk_dsi *dsi = platform_get_drvdata(pdev);
mtk_output_dsi_disable(dsi);
drm_bridge_remove(&dsi->bridge);component_del(&pdev->dev, &mtk_dsi_component_ops); mipi_dsi_host_unregister(&dsi->host); return 0;-- 2.33.1