Commit 3fb1f62f authored by Thomas Zimmermann's avatar Thomas Zimmermann

drm/fb-helper: Remove drm_fb_helper_unprepare() from drm_fb_helper_fini()

Move drm_fb_helper_unprepare() from drm_fb_helper_fini() into the
calling fbdev implementation. Avoids a possible stale mutex with
generic fbdev code.

As indicated by its name, drm_fb_helper_prepare() prepares struct
drm_fb_helper before setting up the fbdev support with a call to
drm_fb_helper_init(). In legacy fbdev emulation, this happens next
to each other. If successful, drm_fb_helper_fini() later tear down
the fbdev device and also unprepare via drm_fb_helper_unprepare().

Generic fbdev emulation prepares struct drm_fb_helper immediately
after allocating the instance. It only calls drm_fb_helper_init()
as part of processing a hotplug event. If the hotplug-handling fails,
it runs drm_fb_helper_fini(). This unprepares the fb-helper instance
and the next hotplug event runs on stale data.

Solve this by moving drm_fb_helper_unprepare() from drm_fb_helper_fini()
into the fbdev implementations. Call it right before freeing the
fb-helper instance.

Fixes: 643231b2 ("drm/fbdev-generic: Minimize hotplug error handling")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230216140620.17699-1-tzimmermann@suse.de
parent fb073aa2
...@@ -147,6 +147,7 @@ int armada_fbdev_init(struct drm_device *dev) ...@@ -147,6 +147,7 @@ int armada_fbdev_init(struct drm_device *dev)
err_fb_setup: err_fb_setup:
drm_fb_helper_fini(fbh); drm_fb_helper_fini(fbh);
err_fb_helper: err_fb_helper:
drm_fb_helper_unprepare(fbh);
priv->fbdev = NULL; priv->fbdev = NULL;
return ret; return ret;
} }
...@@ -164,6 +165,8 @@ void armada_fbdev_fini(struct drm_device *dev) ...@@ -164,6 +165,8 @@ void armada_fbdev_fini(struct drm_device *dev)
if (fbh->fb) if (fbh->fb)
fbh->fb->funcs->destroy(fbh->fb); fbh->fb->funcs->destroy(fbh->fb);
drm_fb_helper_unprepare(fbh);
priv->fbdev = NULL; priv->fbdev = NULL;
} }
} }
...@@ -590,8 +590,6 @@ void drm_fb_helper_fini(struct drm_fb_helper *fb_helper) ...@@ -590,8 +590,6 @@ void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
} }
mutex_unlock(&kernel_fb_helper_lock); mutex_unlock(&kernel_fb_helper_lock);
drm_fb_helper_unprepare(fb_helper);
if (!fb_helper->client.funcs) if (!fb_helper->client.funcs)
drm_client_release(&fb_helper->client); drm_client_release(&fb_helper->client);
} }
......
...@@ -65,6 +65,8 @@ static void drm_fbdev_fb_destroy(struct fb_info *info) ...@@ -65,6 +65,8 @@ static void drm_fbdev_fb_destroy(struct fb_info *info)
drm_client_framebuffer_delete(fb_helper->buffer); drm_client_framebuffer_delete(fb_helper->buffer);
drm_client_release(&fb_helper->client); drm_client_release(&fb_helper->client);
drm_fb_helper_unprepare(fb_helper);
kfree(fb_helper); kfree(fb_helper);
} }
......
...@@ -183,8 +183,8 @@ int exynos_drm_fbdev_init(struct drm_device *dev) ...@@ -183,8 +183,8 @@ int exynos_drm_fbdev_init(struct drm_device *dev)
err_setup: err_setup:
drm_fb_helper_fini(helper); drm_fb_helper_fini(helper);
err_init: err_init:
drm_fb_helper_unprepare(helper);
private->fb_helper = NULL; private->fb_helper = NULL;
kfree(fbdev); kfree(fbdev);
...@@ -219,6 +219,7 @@ void exynos_drm_fbdev_fini(struct drm_device *dev) ...@@ -219,6 +219,7 @@ void exynos_drm_fbdev_fini(struct drm_device *dev)
fbdev = to_exynos_fbdev(private->fb_helper); fbdev = to_exynos_fbdev(private->fb_helper);
exynos_drm_fbdev_destroy(dev, private->fb_helper); exynos_drm_fbdev_destroy(dev, private->fb_helper);
drm_fb_helper_unprepare(private->fb_helper);
kfree(fbdev); kfree(fbdev);
private->fb_helper = NULL; private->fb_helper = NULL;
} }
......
...@@ -427,6 +427,7 @@ int psb_fbdev_init(struct drm_device *dev) ...@@ -427,6 +427,7 @@ int psb_fbdev_init(struct drm_device *dev)
fini: fini:
drm_fb_helper_fini(fb_helper); drm_fb_helper_fini(fb_helper);
free: free:
drm_fb_helper_unprepare(fb_helper);
kfree(fb_helper); kfree(fb_helper);
return ret; return ret;
} }
...@@ -439,6 +440,7 @@ static void psb_fbdev_fini(struct drm_device *dev) ...@@ -439,6 +440,7 @@ static void psb_fbdev_fini(struct drm_device *dev)
return; return;
psb_fbdev_destroy(dev, dev_priv->fb_helper); psb_fbdev_destroy(dev, dev_priv->fb_helper);
drm_fb_helper_unprepare(dev_priv->fb_helper);
kfree(dev_priv->fb_helper); kfree(dev_priv->fb_helper);
dev_priv->fb_helper = NULL; dev_priv->fb_helper = NULL;
} }
......
...@@ -340,6 +340,7 @@ static void intel_fbdev_destroy(struct intel_fbdev *ifbdev) ...@@ -340,6 +340,7 @@ static void intel_fbdev_destroy(struct intel_fbdev *ifbdev)
if (ifbdev->fb) if (ifbdev->fb)
drm_framebuffer_remove(&ifbdev->fb->base); drm_framebuffer_remove(&ifbdev->fb->base);
drm_fb_helper_unprepare(&ifbdev->helper);
kfree(ifbdev); kfree(ifbdev);
} }
......
...@@ -170,6 +170,7 @@ struct drm_fb_helper *msm_fbdev_init(struct drm_device *dev) ...@@ -170,6 +170,7 @@ struct drm_fb_helper *msm_fbdev_init(struct drm_device *dev)
fini: fini:
drm_fb_helper_fini(helper); drm_fb_helper_fini(helper);
fail: fail:
drm_fb_helper_unprepare(helper);
kfree(fbdev); kfree(fbdev);
return NULL; return NULL;
} }
...@@ -196,6 +197,7 @@ void msm_fbdev_free(struct drm_device *dev) ...@@ -196,6 +197,7 @@ void msm_fbdev_free(struct drm_device *dev)
drm_framebuffer_remove(fbdev->fb); drm_framebuffer_remove(fbdev->fb);
} }
drm_fb_helper_unprepare(helper);
kfree(fbdev); kfree(fbdev);
priv->fbdev = NULL; priv->fbdev = NULL;
......
...@@ -256,6 +256,7 @@ void omap_fbdev_init(struct drm_device *dev) ...@@ -256,6 +256,7 @@ void omap_fbdev_init(struct drm_device *dev)
fini: fini:
drm_fb_helper_fini(helper); drm_fb_helper_fini(helper);
fail: fail:
drm_fb_helper_unprepare(helper);
kfree(fbdev); kfree(fbdev);
dev_warn(dev->dev, "omap_fbdev_init failed\n"); dev_warn(dev->dev, "omap_fbdev_init failed\n");
...@@ -286,6 +287,7 @@ void omap_fbdev_fini(struct drm_device *dev) ...@@ -286,6 +287,7 @@ void omap_fbdev_fini(struct drm_device *dev)
if (fbdev->fb) if (fbdev->fb)
drm_framebuffer_remove(fbdev->fb); drm_framebuffer_remove(fbdev->fb);
drm_fb_helper_unprepare(helper);
kfree(fbdev); kfree(fbdev);
priv->fbdev = NULL; priv->fbdev = NULL;
......
...@@ -367,6 +367,7 @@ int radeon_fbdev_init(struct radeon_device *rdev) ...@@ -367,6 +367,7 @@ int radeon_fbdev_init(struct radeon_device *rdev)
fini: fini:
drm_fb_helper_fini(&rfbdev->helper); drm_fb_helper_fini(&rfbdev->helper);
free: free:
drm_fb_helper_unprepare(&rfbdev->helper);
kfree(rfbdev); kfree(rfbdev);
return ret; return ret;
} }
...@@ -377,6 +378,7 @@ void radeon_fbdev_fini(struct radeon_device *rdev) ...@@ -377,6 +378,7 @@ void radeon_fbdev_fini(struct radeon_device *rdev)
return; return;
radeon_fbdev_destroy(rdev->ddev, rdev->mode_info.rfbdev); radeon_fbdev_destroy(rdev->ddev, rdev->mode_info.rfbdev);
drm_fb_helper_unprepare(&rdev->mode_info.rfbdev->helper);
kfree(rdev->mode_info.rfbdev); kfree(rdev->mode_info.rfbdev);
rdev->mode_info.rfbdev = NULL; rdev->mode_info.rfbdev = NULL;
} }
......
...@@ -315,6 +315,7 @@ static struct tegra_fbdev *tegra_fbdev_create(struct drm_device *drm) ...@@ -315,6 +315,7 @@ static struct tegra_fbdev *tegra_fbdev_create(struct drm_device *drm)
static void tegra_fbdev_free(struct tegra_fbdev *fbdev) static void tegra_fbdev_free(struct tegra_fbdev *fbdev)
{ {
drm_fb_helper_unprepare(&fbdev->base);
kfree(fbdev); kfree(fbdev);
} }
......
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