#ifndef __DRM_FB_CMA_HELPER_H__ #define __DRM_FB_CMA_HELPER_H__ struct drm_fbdev_cma; struct drm_gem_cma_object; struct drm_fb_helper_surface_size; struct drm_framebuffer_funcs; struct drm_fb_helper_funcs; struct drm_framebuffer; struct drm_fb_helper; struct drm_device; struct drm_file; struct drm_mode_fb_cmd2; struct drm_plane; struct drm_plane_state; struct drm_fbdev_cma *drm_fbdev_cma_init_with_funcs(struct drm_device *dev, unsigned int preferred_bpp, unsigned int num_crtc, unsigned int max_conn_count, const struct drm_fb_helper_funcs *funcs); struct drm_fbdev_cma *drm_fbdev_cma_init(struct drm_device *dev, unsigned int preferred_bpp, unsigned int num_crtc, unsigned int max_conn_count); void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma); void drm_fbdev_cma_restore_mode(struct drm_fbdev_cma *fbdev_cma); void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma); void drm_fbdev_cma_set_suspend(struct drm_fbdev_cma *fbdev_cma, int state); int drm_fbdev_cma_create_with_funcs(struct drm_fb_helper *helper, struct drm_fb_helper_surface_size *sizes, const struct drm_framebuffer_funcs *funcs); void drm_fb_cma_destroy(struct drm_framebuffer *fb); int drm_fb_cma_create_handle(struct drm_framebuffer *fb, struct drm_file *file_priv, unsigned int *handle); struct drm_framebuffer *drm_fb_cma_create_with_funcs(struct drm_device *dev, struct drm_file *file_priv, const struct drm_mode_fb_cmd2 *mode_cmd, const struct drm_framebuffer_funcs *funcs); struct drm_framebuffer *drm_fb_cma_create(struct drm_device *dev, struct drm_file *file_priv, const struct drm_mode_fb_cmd2 *mode_cmd); struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb, unsigned int plane); int drm_fb_cma_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state); #ifdef CONFIG_DEBUG_FS struct seq_file; int drm_fb_cma_debugfs_show(struct seq_file *m, void *arg); #endif #endif ref='/cgit.cgi/linux/net-next.git/commit/include/drm/drm_dp_dual_mode_helper.h?id=91539eb1fda2d530d3b268eef542c5414e54bf1a'>commitdiff
path: root/include/drm/drm_dp_dual_mode_helper.h
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authorIago Abal <mail@iagoabal.eu>2017-01-11 14:00:21 +0100
committerVinod Koul <vinod.koul@intel.com>2017-01-25 15:35:11 +0530
commit91539eb1fda2d530d3b268eef542c5414e54bf1a (patch)
tree960f5ca6342ad20837aff18aad6e8ecd7da32fd6 /include/drm/drm_dp_dual_mode_helper.h
parent6610d0edf6dc7ee97e46ab3a538a565c79d26199 (diff)
dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the following double-lock bug: Double lock: 1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236; 2. call to function `pl330_release_channel' immediately after; 3. call to function `dma_pl330_rqcb' in line 1753; 4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505. I have fixed it as suggested by Marek Szyprowski. First, I have replaced `pch->lock' with `pl330->lock' in functions `pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids the double-lock by acquiring a different lock than `dma_pl330_rqcb'. NOTE that, as a result, `pl330_free_chan_resources' executes `list_splice_tail_init' on `pch->work_list' under lock `pl330->lock', whereas in the rest of the code `pch->work_list' is protected by `pch->lock'. I don't know if this may cause race conditions. Similarly `pch->cyclic' is written by `pl330_alloc_chan_resources' under `pl330->lock' but read by `pl330_tx_submit' under `pch->lock'. Second, I have removed locking from `pl330_request_channel' and `pl330_release_channel' functions. Function `pl330_request_channel' is only called from `pl330_alloc_chan_resources', so the lock is already held. Function `pl330_release_channel' is called from `pl330_free_chan_resources', which already holds the lock, and from `pl330_del'. Function `pl330_del' is called in an error path of `pl330_probe' and at the end of `pl330_remove', but I assume that there cannot be concurrent accesses to the protected data at those points. Signed-off-by: Iago Abal <mail@iagoabal.eu> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'include/drm/drm_dp_dual_mode_helper.h')