| From 384a2aaec210cc69d53cf9eec2cc7f15b10d7312 Mon Sep 17 00:00:00 2001 |
| From: Dmitry Torokhov <dtor@chromium.org> |
| Date: Tue, 8 Sep 2015 17:30:52 -0700 |
| Subject: [PATCH 2/3] CHROMIUM: android: fix warning when releasing active sync |
| point |
| |
| Userspace can close the sync device while there are still active fence |
| points, in which case kernel produces the following warning: |
| |
| [ 43.853176] ------------[ cut here ]------------ |
| [ 43.857834] WARNING: CPU: 0 PID: 892 at /mnt/host/source/src/third_party/kernel/v3.18/drivers/staging/android/sync.c:439 android_fence_release+0x88/0x104() |
| [ 43.871741] CPU: 0 PID: 892 Comm: Binder_5 Tainted: G U 3.18.0-07661-g0550ce9 #1 |
| [ 43.880176] Hardware name: Google Tegra210 Smaug Rev 1+ (DT) |
| [ 43.885834] Call trace: |
| [ 43.888294] [<ffffffc000207464>] dump_backtrace+0x0/0x10c |
| [ 43.893697] [<ffffffc000207580>] show_stack+0x10/0x1c |
| [ 43.898756] [<ffffffc000ab1258>] dump_stack+0x74/0xb8 |
| [ 43.903814] [<ffffffc00021d414>] warn_slowpath_common+0x84/0xb0 |
| [ 43.909736] [<ffffffc00021d530>] warn_slowpath_null+0x14/0x20 |
| [ 43.915482] [<ffffffc00088aefc>] android_fence_release+0x84/0x104 |
| [ 43.921582] [<ffffffc000671cc4>] fence_release+0x104/0x134 |
| [ 43.927066] [<ffffffc00088b0cc>] sync_fence_free+0x74/0x9c |
| [ 43.932552] [<ffffffc00088b128>] sync_fence_release+0x34/0x48 |
| [ 43.938304] [<ffffffc000317bbc>] __fput+0x100/0x1b8 |
| [ 43.943185] [<ffffffc000317cc8>] ____fput+0x8/0x14 |
| [ 43.947982] [<ffffffc000237f38>] task_work_run+0xb0/0xe4 |
| [ 43.953297] [<ffffffc000207074>] do_notify_resume+0x44/0x5c |
| [ 43.958867] ---[ end trace 5a2aa4027cc5d171 ]--- |
| |
| Let's fix it by introducing a new optional callback (disable_signaling) |
| to fence operations so that drivers can do proper clean ups when we |
| remove last callback for given fence. |
| |
| Signed-off-by: Dmitry Torokhov <dtor@chromium.org> |
| Reviewed-on: https://chromium-review.googlesource.com/303409 |
| Reviewed-by: Andrew Bresticker <abrestic@chromium.org> |
| Signed-off-by: Jin Qian <jinqian@android.com> |
| --- |
| drivers/dma-buf/dma-fence.c | 6 +++++- |
| include/linux/dma-fence.h | 2 ++ |
| 2 files changed, 7 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/dma-buf/dma-fence.c |
| +++ b/drivers/dma-buf/dma-fence.c |
| @@ -332,8 +332,12 @@ dma_fence_remove_callback(struct dma_fen |
| spin_lock_irqsave(fence->lock, flags); |
| |
| ret = !list_empty(&cb->node); |
| - if (ret) |
| + if (ret) { |
| list_del_init(&cb->node); |
| + if (list_empty(&fence->cb_list)) |
| + if (fence->ops->disable_signaling) |
| + fence->ops->disable_signaling(fence); |
| + } |
| |
| spin_unlock_irqrestore(fence->lock, flags); |
| |
| --- a/include/linux/dma-fence.h |
| +++ b/include/linux/dma-fence.h |
| @@ -109,6 +109,7 @@ struct dma_fence_cb { |
| * @get_driver_name: returns the driver name. |
| * @get_timeline_name: return the name of the context this fence belongs to. |
| * @enable_signaling: enable software signaling of fence. |
| + * @disable_signaling: disable software signaling of fence (optional). |
| * @signaled: [optional] peek whether the fence is signaled, can be null. |
| * @wait: custom wait implementation, or dma_fence_default_wait. |
| * @release: [optional] called on destruction of fence, can be null |
| @@ -168,6 +169,7 @@ struct dma_fence_ops { |
| const char * (*get_driver_name)(struct dma_fence *fence); |
| const char * (*get_timeline_name)(struct dma_fence *fence); |
| bool (*enable_signaling)(struct dma_fence *fence); |
| + void (*disable_signaling)(struct dma_fence *fence); |
| bool (*signaled)(struct dma_fence *fence); |
| signed long (*wait)(struct dma_fence *fence, |
| bool intr, signed long timeout); |
