diff options
| author | Shengjiu Wang <shengjiu.wang@freescale.com> | 2015-07-13 19:19:15 +0800 |
|---|---|---|
| committer | Nitin Garg <nitin.garg@freescale.com> | 2015-09-17 09:24:05 -0500 |
| commit | 9dc8dd91bafe1bb4f62e3ff7124932271b04aea3 (patch) | |
| tree | e60fe0f93be8e5bdce6381d964dd4c44749ba341 /include | |
| parent | 8db5ce2826583b7c65d97cc0cc8d856e6156b3b9 (diff) | |
MLK-11248: dmaengine: imx-sdma: add new api for sync with dma and substream
There is occasion that dma callback come late after the substream is released.
Then there will be kernel dump.
[<805866b0>] (imx_pcm_dma_complete) from [<802fad9c>] (sdma_handle_channel_loop.isra.25+0x48/0x54)
[<802fad9c>] (sdma_handle_channel_loop.isra.25) from [<802fae48>] (sdma_tasklet+0xa0/0x1d4)
[<802fae48>] (sdma_tasklet) from [<800356e0>] (tasklet_action+0x64/0xf8)
[<800356e0>] (tasklet_action) from [<80034ea0>] (__do_softirq+0x104/0x218)
[<80034ea0>] (__do_softirq) from [<80035220>] (irq_exit+0xa8/0xec)
[<80035220>] (irq_exit) from [<8000ed44>] (handle_IRQ+0x3c/0x90)
[<8000ed44>] (handle_IRQ) from [<80008578>] (gic_handle_irq+0x28/0x5c)
[<80008578>] (gic_handle_irq) from [<80012100>] (__irq_svc+0x40/0x70)
The reason is the sdma tasklet is async with audio substream release. ALSA
think when terminate dma, the dma should be stopped and no callback be called.
This patch is to add new api dma_sync_wait_tasklet(), which is called in
snd_dmaengine_pcm_close(). It will make sure the callback not be called
after this funtion. Tasklet_kill is to wait scheduled tasklet end.
Tasklet_kill can't be added to terminate dma function, because terminate dma
function may be called in interrupt, but tasklet_kill can't be called in
interrupt context.
Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/dmaengine.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 0a5f55272672..36c218c43a48 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -681,6 +681,7 @@ struct dma_device { int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned long arg); + enum dma_status (*device_wait_tasklet)(struct dma_chan *chan); enum dma_status (*device_tx_status)(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate); @@ -1062,6 +1063,8 @@ dma_set_tx_state(struct dma_tx_state *st, dma_cookie_t last, dma_cookie_t used, } } +enum dma_status dma_sync_wait_tasklet(struct dma_chan *chan); + #ifdef CONFIG_DMA_ENGINE struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type); enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie); |