From 38992c57c9c8425dc9cb75efe6f9b9255ea627a0 Mon Sep 17 00:00:00 2001 From: Jyri Sarha Date: Thu, 26 Apr 2018 11:06:59 +0300 Subject: drm/panel: Remove drm_panel_detach() calls from all panel drivers Remove all drm_panel_detach() calls from all panel drivers and update the kerneldoc for drm_panel_detach(). Setting the connector and drm to NULL when the DRM panel device is going away hardly serves any purpose. Usually the whole memory structure is freed right after the remove call. However, calling the detach function from the master DRM device, and setting the connector pointer to NULL, has the logic of marking the panel again as available for another DRM master to attach. The usual situation would be the same DRM master device binding again. Signed-off-by: Jyri Sarha Reviewed-by: Daniel Vetter Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/464b8d330d6b4c94cfb5aad2ca9ea7eb2c52d934.1524727888.git.jsarha@ti.com --- drivers/gpu/drm/drm_panel.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/gpu/drm/drm_panel.c') diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 308d442a531b..71e407574276 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -94,6 +94,9 @@ EXPORT_SYMBOL(drm_panel_remove); * * An error is returned if the panel is already attached to another connector. * + * When unloading, the driver should detach from the panel by calling + * drm_panel_detach(). + * * Return: 0 on success or a negative error code on failure. */ int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector) @@ -115,6 +118,9 @@ EXPORT_SYMBOL(drm_panel_attach); * Detaches a panel from the connector it is attached to. If a panel is not * attached to any connector this is effectively a no-op. * + * This function should not be called by the panel device itself. It + * is only for the drm device that called drm_panel_attach(). + * * Return: 0 on success or a negative error code on failure. */ int drm_panel_detach(struct drm_panel *panel) -- cgit From 0c08754b59da5557532d946599854e6df28edc22 Mon Sep 17 00:00:00 2001 From: Jyri Sarha Date: Thu, 26 Apr 2018 11:07:00 +0300 Subject: drm/panel: Add device_link from panel device to DRM device Add device_link from panel device (supplier) to DRM device (consumer) when drm_panel_attach() is called. This patch should protect the master DRM driver if an attached panel driver unbinds while it is in use. The device_link should make sure the DRM device is unbound before the panel driver becomes unavailable. The device_link is removed when drm_panel_detach() is called. The drm_panel_detach() should be called by the consumer DRM driver, not the panel driver, otherwise both drivers are racing to delete the same link. Signed-off-by: Jyri Sarha Reviewed-by: Eric Anholt Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/b53584fd988d045c13de22d81825395b0ae0aad7.1524727888.git.jsarha@ti.com --- drivers/gpu/drm/drm_panel.c | 10 ++++++++++ include/drm/drm_panel.h | 1 + 2 files changed, 11 insertions(+) (limited to 'drivers/gpu/drm/drm_panel.c') diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 71e407574276..965530a6f4cd 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -24,6 +24,7 @@ #include #include +#include #include #include @@ -104,6 +105,13 @@ int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector) if (panel->connector) return -EBUSY; + panel->link = device_link_add(connector->dev->dev, panel->dev, 0); + if (!panel->link) { + dev_err(panel->dev, "failed to link panel to %s\n", + dev_name(connector->dev->dev)); + return -EINVAL; + } + panel->connector = connector; panel->drm = connector->dev; @@ -125,6 +133,8 @@ EXPORT_SYMBOL(drm_panel_attach); */ int drm_panel_detach(struct drm_panel *panel) { + device_link_del(panel->link); + panel->connector = NULL; panel->drm = NULL; diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 14ac240a1f64..26a1b5fd8796 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -89,6 +89,7 @@ struct drm_panel { struct drm_device *drm; struct drm_connector *connector; struct device *dev; + struct device_link *link; const struct drm_panel_funcs *funcs; -- cgit From 5fa8e4a22182df8ea39adeba4bd518506e26a96d Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Wed, 9 May 2018 15:00:39 +0200 Subject: drm/panel: Make of_drm_find_panel() return an ERR_PTR() instead of NULL Right now, the DRM panel logic returns NULL when a panel pointing to the passed OF node is not present in the list of registered panels. Most drivers interpret this NULL value as -EPROBE_DEFER, but we are about to modify the semantic of of_drm_find_panel() and let the framework return -ENODEV when the device node we're pointing to has a status property that is not equal to "okay" or "ok". Let's first patch the of_drm_find_panel() implementation to return ERR_PTR(-EPROBE_DEFER) instead of NULL and patch all callers to replace the '!panel' check by an 'IS_ERR(panel)' one. Signed-off-by: Boris Brezillon Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20180509130042.9435-2-boris.brezillon@bootlin.com --- drivers/gpu/drm/bridge/cdns-dsi.c | 2 +- drivers/gpu/drm/bridge/lvds-encoder.c | 4 ++-- drivers/gpu/drm/drm_of.c | 4 +++- drivers/gpu/drm/drm_panel.c | 6 ++++-- drivers/gpu/drm/exynos/exynos_dp.c | 6 ++++-- drivers/gpu/drm/exynos/exynos_drm_dpi.c | 4 ++-- drivers/gpu/drm/exynos/exynos_drm_dsi.c | 3 +++ drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c | 5 +++-- drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c | 4 ++-- drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 5 ++++- drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +- drivers/gpu/drm/rcar-du/rcar_lvds.c | 4 ++-- drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 2 +- drivers/gpu/drm/sti/sti_dvo.c | 4 +++- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 4 ++-- drivers/gpu/drm/tegra/dsi.c | 3 +++ drivers/gpu/drm/tegra/output.c | 4 ++-- include/drm/drm_panel.h | 2 +- 18 files changed, 43 insertions(+), 25 deletions(-) (limited to 'drivers/gpu/drm/drm_panel.c') diff --git a/drivers/gpu/drm/bridge/cdns-dsi.c b/drivers/gpu/drm/bridge/cdns-dsi.c index f2d43f24acfb..ce9496d13986 100644 --- a/drivers/gpu/drm/bridge/cdns-dsi.c +++ b/drivers/gpu/drm/bridge/cdns-dsi.c @@ -1152,7 +1152,7 @@ static int cdns_dsi_attach(struct mipi_dsi_host *host, np = of_node_get(dev->dev.of_node); panel = of_drm_find_panel(np); - if (panel) { + if (!IS_ERR(panel)) { bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI); } else { bridge = of_drm_find_bridge(dev->dev.of_node); diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c b/drivers/gpu/drm/bridge/lvds-encoder.c index 75b0d3f6e4de..f56c92f7af7c 100644 --- a/drivers/gpu/drm/bridge/lvds-encoder.c +++ b/drivers/gpu/drm/bridge/lvds-encoder.c @@ -68,9 +68,9 @@ static int lvds_encoder_probe(struct platform_device *pdev) panel = of_drm_find_panel(panel_node); of_node_put(panel_node); - if (!panel) { + if (IS_ERR(panel)) { dev_dbg(&pdev->dev, "panel not found, deferring probe\n"); - return -EPROBE_DEFER; + return PTR_ERR(panel); } lvds_encoder->panel_bridge = diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c index 3b8c7a6a5720..1f4a16772583 100644 --- a/drivers/gpu/drm/drm_of.c +++ b/drivers/gpu/drm/drm_of.c @@ -241,8 +241,10 @@ int drm_of_find_panel_or_bridge(const struct device_node *np, if (panel) { *panel = of_drm_find_panel(remote); - if (*panel) + if (!IS_ERR(*panel)) ret = 0; + else + *panel = NULL; } /* No panel found yet, check for a bridge next. */ diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 965530a6f4cd..7e5530a04846 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -151,7 +151,9 @@ EXPORT_SYMBOL(drm_panel_detach); * tree node. If a matching panel is found, return a pointer to it. * * Return: A pointer to the panel registered for the specified device tree - * node or NULL if no panel matching the device tree node can be found. + * node or an ERR_PTR() if no panel matching the device tree node can be found. + * The only error that can be reported is -EPROBE_DEFER, meaning that the panel + * device has not been probed yet, and the caller should retry later. */ struct drm_panel *of_drm_find_panel(const struct device_node *np) { @@ -167,7 +169,7 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np) } mutex_unlock(&panel_lock); - return NULL; + return ERR_PTR(-EPROBE_DEFER); } EXPORT_SYMBOL(of_drm_find_panel); #endif diff --git a/drivers/gpu/drm/exynos/exynos_dp.c b/drivers/gpu/drm/exynos/exynos_dp.c index 86330f396784..af7ab1ceb50f 100644 --- a/drivers/gpu/drm/exynos/exynos_dp.c +++ b/drivers/gpu/drm/exynos/exynos_dp.c @@ -232,9 +232,11 @@ static int exynos_dp_probe(struct platform_device *pdev) np = of_parse_phandle(dev->of_node, "panel", 0); if (np) { dp->plat_data.panel = of_drm_find_panel(np); + of_node_put(np); - if (!dp->plat_data.panel) - return -EPROBE_DEFER; + if (IS_ERR(dp->plat_data.panel)) + return PTR_ERR(dp->plat_data.panel); + goto out; } diff --git a/drivers/gpu/drm/exynos/exynos_drm_dpi.c b/drivers/gpu/drm/exynos/exynos_drm_dpi.c index 66945e0dc57f..5887e8522b70 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dpi.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dpi.c @@ -240,8 +240,8 @@ struct drm_encoder *exynos_dpi_probe(struct device *dev) if (ctx->panel_node) { ctx->panel = of_drm_find_panel(ctx->panel_node); - if (!ctx->panel) - return ERR_PTR(-EPROBE_DEFER); + if (IS_ERR(ctx->panel)) + return ERR_CAST(ctx->panel); } return &ctx->encoder; diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c index 6d29777884f9..809e1e0447df 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c @@ -1519,6 +1519,9 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host, dsi->format = device->format; dsi->mode_flags = device->mode_flags; dsi->panel = of_drm_find_panel(device->dev.of_node); + if (IS_ERR(dsi->panel)) + dsi->panel = NULL; + if (dsi->panel) { drm_panel_attach(dsi->panel, &dsi->connector); dsi->connector.status = connector_status_connected; diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c index c54806d08dd7..681e2a07d03b 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c @@ -148,8 +148,9 @@ int fsl_dcu_create_outputs(struct fsl_dcu_drm_device *fsl_dev) if (panel_node) { fsl_dev->connector.panel = of_drm_find_panel(panel_node); of_node_put(panel_node); - if (!fsl_dev->connector.panel) - return -EPROBE_DEFER; + if (IS_ERR(fsl_dev->connector.panel)) + return PTR_ERR(fsl_dev->connector.panel); + return fsl_dcu_attach_panel(fsl_dev, fsl_dev->connector.panel); } diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c index 4a645926edb7..2bfb39082f54 100644 --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c @@ -341,7 +341,7 @@ static void mdp4_lcdc_encoder_disable(struct drm_encoder *encoder) mdp4_write(mdp4_kms, REG_MDP4_LCDC_ENABLE, 0); panel = of_drm_find_panel(mdp4_lcdc_encoder->panel_node); - if (panel) { + if (!IS_ERR(panel)) { drm_panel_disable(panel); drm_panel_unprepare(panel); } @@ -410,7 +410,7 @@ static void mdp4_lcdc_encoder_enable(struct drm_encoder *encoder) dev_err(dev->dev, "failed to enable lcdc_clk: %d\n", ret); panel = of_drm_find_panel(mdp4_lcdc_encoder->panel_node); - if (panel) { + if (!IS_ERR(panel)) { drm_panel_prepare(panel); drm_panel_enable(panel); } diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c index e3b1c86b7aae..32fba5664b0e 100644 --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c @@ -34,9 +34,12 @@ static enum drm_connector_status mdp4_lvds_connector_detect( struct mdp4_lvds_connector *mdp4_lvds_connector = to_mdp4_lvds_connector(connector); - if (!mdp4_lvds_connector->panel) + if (!mdp4_lvds_connector->panel) { mdp4_lvds_connector->panel = of_drm_find_panel(mdp4_lvds_connector->panel_node); + if (IS_ERR(mdp4_lvds_connector->panel)) + mdp4_lvds_connector->panel = NULL; + } return mdp4_lvds_connector->panel ? connector_status_connected : diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 2f1a2780658a..29841f440111 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1898,7 +1898,7 @@ int msm_dsi_host_register(struct mipi_dsi_host *host, bool check_defer) * output */ if (check_defer && msm_host->device_node) { - if (!of_drm_find_panel(msm_host->device_node)) + if (IS_ERR(of_drm_find_panel(msm_host->device_node))) if (!of_drm_find_bridge(msm_host->device_node)) return -EPROBE_DEFER; } diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c index 155ad840f3c5..5d8e391e75f4 100644 --- a/drivers/gpu/drm/rcar-du/rcar_lvds.c +++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c @@ -434,8 +434,8 @@ static int rcar_lvds_parse_dt(struct rcar_lvds *lvds) ret = -EPROBE_DEFER; } else { lvds->panel = of_drm_find_panel(remote); - if (!lvds->panel) - ret = -EPROBE_DEFER; + if (IS_ERR(lvds->panel)) + ret = PTR_ERR(lvds->panel); } done: diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c index d53d5a09547f..01642aaf6127 100644 --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c @@ -595,7 +595,7 @@ static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host, dsi->format = device->format; dsi->mode_flags = device->mode_flags; dsi->panel = of_drm_find_panel(device->dev.of_node); - if (dsi->panel) + if (!IS_ERR(dsi->panel)) return drm_panel_attach(dsi->panel, &dsi->connector); return -EINVAL; diff --git a/drivers/gpu/drm/sti/sti_dvo.c b/drivers/gpu/drm/sti/sti_dvo.c index a5979cd25cc7..030da55a8d30 100644 --- a/drivers/gpu/drm/sti/sti_dvo.c +++ b/drivers/gpu/drm/sti/sti_dvo.c @@ -387,7 +387,9 @@ sti_dvo_connector_detect(struct drm_connector *connector, bool force) if (!dvo->panel) { dvo->panel = of_drm_find_panel(dvo->panel_node); - if (dvo->panel) + if (IS_ERR(dvo->panel)) + dvo->panel = NULL; + else drm_panel_attach(dvo->panel, connector); } diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index da9814f94d00..2b40d1f6aee8 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -833,8 +833,8 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host, dsi->device = device; dsi->panel = of_drm_find_panel(device->dev.of_node); - if (!dsi->panel) - return -EINVAL; + if (IS_ERR(dsi->panel)) + return PTR_ERR(dsi->panel); dev_info(host->dev, "Attached device %s\n", device->name); diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c index 87c5d89bc9ba..ad88ec230329 100644 --- a/drivers/gpu/drm/tegra/dsi.c +++ b/drivers/gpu/drm/tegra/dsi.c @@ -1411,6 +1411,9 @@ static int tegra_dsi_host_attach(struct mipi_dsi_host *host, struct tegra_output *output = &dsi->output; output->panel = of_drm_find_panel(device->dev.of_node); + if (IS_ERR(output->panel)) + output->panel = NULL; + if (output->panel && output->connector.dev) { drm_panel_attach(output->panel, &output->connector); drm_helper_hpd_irq_event(output->connector.dev); diff --git a/drivers/gpu/drm/tegra/output.c b/drivers/gpu/drm/tegra/output.c index ffe34bd0bb9d..0c0936511bb4 100644 --- a/drivers/gpu/drm/tegra/output.c +++ b/drivers/gpu/drm/tegra/output.c @@ -110,8 +110,8 @@ int tegra_output_probe(struct tegra_output *output) panel = of_parse_phandle(output->of_node, "nvidia,panel", 0); if (panel) { output->panel = of_drm_find_panel(panel); - if (!output->panel) - return -EPROBE_DEFER; + if (IS_ERR(output->panel)) + return PTR_ERR(output->panel); of_node_put(panel); } diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 26a1b5fd8796..582a0ec0aa70 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -200,7 +200,7 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np); #else static inline struct drm_panel *of_drm_find_panel(const struct device_node *np) { - return NULL; + return ERR_PTR(-ENODEV); } #endif -- cgit From c59eb3cfde1faed960fe6de5040c4bd4310fb1cd Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Wed, 9 May 2018 15:00:40 +0200 Subject: drm/panel: Let of_drm_find_panel() return -ENODEV when the panel is disabled DT nodes might be present in the DT but with a status property set to "disabled" or "fail". In this case, we should not return -EPROBE_DEFER when the caller asks for a drm_panel instance. Return -ENODEV instead. Signed-off-by: Boris Brezillon Reviewed-by: Thierry Reding Acked-by: Thierry Reding Signed-off-by: Thierry Reding Link: https://patchwork.freedesktop.org/patch/msgid/20180509130042.9435-3-boris.brezillon@bootlin.com --- drivers/gpu/drm/drm_panel.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/drm_panel.c') diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 7e5530a04846..b902361dee6e 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -152,13 +152,18 @@ EXPORT_SYMBOL(drm_panel_detach); * * Return: A pointer to the panel registered for the specified device tree * node or an ERR_PTR() if no panel matching the device tree node can be found. - * The only error that can be reported is -EPROBE_DEFER, meaning that the panel - * device has not been probed yet, and the caller should retry later. + * Possible error codes returned by this function: + * - EPROBE_DEFER: the panel device has not been probed yet, and the caller + * should retry later + * - ENODEV: the device is not available (status != "okay" or "ok") */ struct drm_panel *of_drm_find_panel(const struct device_node *np) { struct drm_panel *panel; + if (!of_device_is_available(np)) + return ERR_PTR(-ENODEV); + mutex_lock(&panel_lock); list_for_each_entry(panel, &panel_list, list) { -- cgit