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| author | Inki Dae <inki.dae@samsung.com> | 2013-07-22 12:42:35 +0900 |
|---|---|---|
| committer | Chanho Park <chanho61.park@samsung.com> | 2014-11-18 11:43:39 +0900 |
| commit | 1c2486404dac7b2835574a7aa73e12312f4d5401 (patch) | |
| tree | cbd0b9f24ce96156f177fede4627aa74418d9158 /drivers/base | |
| parent | ccd9fc42ccafc0513efcf7a92fa42a0a3760550d (diff) | |
| download | linux-3.10-1c2486404dac7b2835574a7aa73e12312f4d5401.tar.gz linux-3.10-1c2486404dac7b2835574a7aa73e12312f4d5401.tar.bz2 linux-3.10-1c2486404dac7b2835574a7aa73e12312f4d5401.zip | |
dmabuf-sync: fix sync lock to multiple read
This patch fixes the issue that a sync object is unlocked
when shared_cnt is bigger than 1 and sobj->access_type is write.
the below number means shared_cnt and three sync objects share
one buffer,
r r r w
when write locked 1 2 3 3 <- blocked
when read unlocked 2
when read unlocked 1
when read unlocked 1 <- waked up
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/dmabuf-sync.c | 43 |
1 files changed, 13 insertions, 30 deletions
diff --git a/drivers/base/dmabuf-sync.c b/drivers/base/dmabuf-sync.c index a4b8a50a2fe..14c0c6f6d42 100644 --- a/drivers/base/dmabuf-sync.c +++ b/drivers/base/dmabuf-sync.c @@ -63,8 +63,7 @@ static void dmabuf_sync_timeout_worker(struct work_struct *work) continue; } - if (sobj->robj->shared && - atomic_add_unless(&sobj->robj->shared_cnt, -1, 1)) { + if (atomic_add_unless(&sobj->robj->shared_cnt, -1, 1)) { mutex_unlock(&sobj->robj->lock); continue; } @@ -74,6 +73,7 @@ static void dmabuf_sync_timeout_worker(struct work_struct *work) ww_mutex_unlock(&sobj->robj->sync_lock); mutex_lock(&sobj->robj->lock); + sobj->robj->locked = false; if (sobj->access_type & DMA_BUF_ACCESS_R) printk(KERN_WARNING "%s: r-unlocked = 0x%x\n", @@ -183,7 +183,6 @@ retry: if (sobj->robj->accessed_type & DMA_BUF_ACCESS_R && sobj->access_type & DMA_BUF_ACCESS_R) { atomic_inc(&sobj->robj->shared_cnt); - sobj->robj->shared = true; mutex_unlock(&sobj->robj->lock); continue; } @@ -278,29 +277,17 @@ static void dmabuf_sync_unlock_objs(struct dmabuf_sync *sync, list_for_each_entry(sobj, &sync->syncs, head) { mutex_lock(&sobj->robj->lock); - if (sobj->robj->shared) { - if (atomic_add_unless(&sobj->robj->shared_cnt, -1, - 1)) { - mutex_unlock(&sobj->robj->lock); - continue; - } - - mutex_unlock(&sobj->robj->lock); - - ww_mutex_unlock(&sobj->robj->sync_lock); - - mutex_lock(&sobj->robj->lock); - sobj->robj->shared = false; - sobj->robj->locked = false; - } else { + if (atomic_add_unless(&sobj->robj->shared_cnt, -1, 1)) { mutex_unlock(&sobj->robj->lock); + continue; + } - ww_mutex_unlock(&sobj->robj->sync_lock); + mutex_unlock(&sobj->robj->lock); - mutex_lock(&sobj->robj->lock); - sobj->robj->locked = false; - } + ww_mutex_unlock(&sobj->robj->sync_lock); + mutex_lock(&sobj->robj->lock); + sobj->robj->locked = false; mutex_unlock(&sobj->robj->lock); } @@ -585,7 +572,6 @@ int dmabuf_sync_single_lock(struct dma_buf *dmabuf, unsigned int type, /* Don't lock in case of read and read. */ if (robj->accessed_type & DMA_BUF_ACCESS_R && type & DMA_BUF_ACCESS_R) { atomic_inc(&robj->shared_cnt); - robj->shared = true; mutex_unlock(&robj->lock); return 0; } @@ -635,13 +621,10 @@ void dmabuf_sync_single_unlock(struct dma_buf *dmabuf) mutex_lock(&robj->lock); - if (robj->shared) { - if (atomic_add_unless(&robj->shared_cnt, -1 , 1)) { - mutex_unlock(&robj->lock); - return; - } - - robj->shared = false; + if (atomic_add_unless(&robj->shared_cnt, -1 , 1)) { + mutex_unlock(&robj->lock); + dma_buf_put(dmabuf); + return; } mutex_unlock(&robj->lock); |