+++ /dev/null
-From 70db39b21100039062b6e3703491a3fb9c0bb3e5 Mon Sep 17 00:00:00 2001
-From: Sasha Levin <sashal@kernel.org>
-Date: Mon, 31 Jan 2022 09:55:20 +0100
-Subject: drm/mediatek: mtk_dsi: Avoid EPROBE_DEFER loop with external bridge
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
-
-[ Upstream commit 647474b8d980256b26b1cd112d7333a4dbd4260a ]
-
-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).
-
-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>
-Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
-Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
-Signed-off-by: Sasha Levin <sashal@kernel.org>
----
- 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;
---
-2.35.1
-
projects / thirdparty / kernel / stable-queue.git / commitdiff
