On 22 June 2015 at 14:02, Daniel Vetter daniel.vetter@ffwll.ch wrote:
We should never nest these since in theory kms drivers should know when a pipe is on/off and call the corresponding enable/disable functions for the vblank helper code only once. But for historical reasons (the shared-with-ums version of this code in modeset_pre/post needed to be able to cope with silly userspace that lost track of things) we still have this bit of "robustness" around.
Enforce this with a WARN_ON, preparing to eventually rip out this special handling.
Hello,
just wanted to mention that this warning triggered on tegra124 and that I find it a bit disruptive:
WARNING: CPU: 0 PID: 52 at drivers/gpu/drm/drm_irq.c:1323 drm_vblank_on+0x10c/0x130() Modules linked in: CPU: 0 PID: 52 Comm: kworker/0:1 Not tainted 4.1.0-next-20150625ccu-00024-gd8cbda3 #2295 Hardware name: NVIDIA Tegra SoC (Flattened Device Tree) Workqueue: events output_poll_execute [<c021b12c>] (unwind_backtrace) from [<c0215388>] (show_stack+0x20/0x24) [<c0215388>] (show_stack) from [<c0a9637c>] (dump_stack+0x8c/0x9c) [<c0a9637c>] (dump_stack) from [<c0256b58>] (warn_slowpath_common+0x94/0xc4) [<c0256b58>] (warn_slowpath_common) from [<c0256c44>] (warn_slowpath_null+0x2c/0x34) [<c0256c44>] (warn_slowpath_null) from [<c0686d38>] (drm_vblank_on+0x10c/0x130) [<c0686d38>] (drm_vblank_on) from [<c0686d84>] (drm_crtc_vblank_on+0x28/0x2c) [<c0686d84>] (drm_crtc_vblank_on) from [<c06cd518>] (tegra_crtc_commit+0x18/0x1c) [<c06cd518>] (tegra_crtc_commit) from [<c067b014>] (drm_atomic_helper_commit_modeset_enables+0xa0/0x198) [<c067b014>] (drm_atomic_helper_commit_modeset_enables) from [<c06cb068>] (tegra_atomic_complete.isra.1+0x38/0x5c) [<c06cb068>] (tegra_atomic_complete.isra.1) from [<c06cb0f4>] (tegra_atomic_commit+0x68/0x98) [<c06cb0f4>] (tegra_atomic_commit) from [<c06a1690>] (drm_atomic_commit+0x54/0x74) [<c06a1690>] (drm_atomic_commit) from [<c067b6ec>] (drm_atomic_helper_set_config+0x1b4/0x414) [<c067b6ec>] (drm_atomic_helper_set_config) from [<c068f43c>] (drm_mode_set_config_internal+0x68/0xe4) [<c068f43c>] (drm_mode_set_config_internal) from [<c067d34c>] (restore_fbdev_mode+0xe8/0x108) [<c067d34c>] (restore_fbdev_mode) from [<c067f390>] (drm_fb_helper_restore_fbdev_mode_unlocked+0x2c/0x68) [<c067f390>] (drm_fb_helper_restore_fbdev_mode_unlocked) from [<c067f3f4>] (drm_fb_helper_set_par+0x28/0x44) [<c067f3f4>] (drm_fb_helper_set_par) from [<c067f328>] (drm_fb_helper_hotplug_event+0xcc/0x108) [<c067f328>] (drm_fb_helper_hotplug_event) from [<c06cce98>] (tegra_fb_output_poll_changed+0x28/0x2c) [<c06cce98>] (tegra_fb_output_poll_changed) from [<c0674228>] (drm_kms_helper_hotplug_event+0x34/0x38) [<c0674228>] (drm_kms_helper_hotplug_event) from [<c06743dc>] (output_poll_execute+0x158/0x198) [<c06743dc>] (output_poll_execute) from [<c026d830>] (process_one_work+0x154/0x48c) [<c026d830>] (process_one_work) from [<c026dbbc>] (worker_thread+0x54/0x568) [<c026dbbc>] (worker_thread) from [<c02739ec>] (kthread+0xec/0x104) [<c02739ec>] (kthread) from [<c0211228>] (ret_from_fork+0x14/0x2c)
Regards,
Tomeu
Cc: Yogesh Mohan Marimuthu yogesh.mohan.marimuthu@intel.com Cc: Gaurav K Singh gaurav.k.singh@intel.com Cc: Michel Dänzer michel.daenzer@amd.com Cc: Ville Syrjälä ville.syrjala@linux.intel.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com
drivers/gpu/drm/drm_irq.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index f9cc68fbd2a3..3819465abe22 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1219,6 +1219,8 @@ void drm_vblank_off(struct drm_device *dev, int crtc) vblank_disable_and_save(dev, crtc); wake_up(&vblank->queue);
WARN_ON(vblank->inmodeset);/* * Prevent subsequent drm_vblank_get() from re-enabling * the vblank interrupt by bumping the refcount.@@ -1318,6 +1320,8 @@ void drm_vblank_on(struct drm_device *dev, int crtc) return;
spin_lock_irqsave(&dev->vbl_lock, irqflags);
WARN_ON(!vblank->inmodeset);/* Drop our private "prevent drm_vblank_get" refcount */ if (vblank->inmodeset) { atomic_dec(&vblank->refcount);-- 2.1.4
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