dmaengine: ep93xx: Don't drain the transfers in terminate_all()
Draining the transfers in terminate_all callback happens with IRQs disabled, therefore induces huge latency: irqsoff latency trace v1.1.5 on 4.11.0 -------------------------------------------------------------------- latency: 39770 us, #57/57, CPU#0 | (M:preempt VP:0, KP:0, SP:0 HP:0) ----------------- | task: process-129 (uid:0 nice:0 policy:2 rt_prio:50) ----------------- => started at: _snd_pcm_stream_lock_irqsave => ended at: snd_pcm_stream_unlock_irqrestore _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / delay cmd pid ||||| time | caller \ / ||||| \ | / process-129 0d.s. 3us : _snd_pcm_stream_lock_irqsave process-129 0d.s1 9us : snd_pcm_stream_lock <-_snd_pcm_stream_lock_irqsave process-129 0d.s1 15us : preempt_count_add <-snd_pcm_stream_lock process-129 0d.s2 22us : preempt_count_add <-snd_pcm_stream_lock process-129 0d.s3 32us : snd_pcm_update_hw_ptr0 <-snd_pcm_period_elapsed process-129 0d.s3 41us : soc_pcm_pointer <-snd_pcm_update_hw_ptr0 process-129 0d.s3 50us : dmaengine_pcm_pointer <-soc_pcm_pointer process-129 0d.s3 58us+: snd_dmaengine_pcm_pointer_no_residue <-dmaengine_pcm_pointer process-129 0d.s3 96us : update_audio_tstamp <-snd_pcm_update_hw_ptr0 process-129 0d.s3 103us : snd_pcm_update_state <-snd_pcm_update_hw_ptr0 process-129 0d.s3 112us : xrun <-snd_pcm_update_state process-129 0d.s3 119us : snd_pcm_stop <-xrun process-129 0d.s3 126us : snd_pcm_action <-snd_pcm_stop process-129 0d.s3 134us : snd_pcm_action_single <-snd_pcm_action process-129 0d.s3 141us : snd_pcm_pre_stop <-snd_pcm_action_single process-129 0d.s3 150us : snd_pcm_do_stop <-snd_pcm_action_single process-129 0d.s3 157us : soc_pcm_trigger <-snd_pcm_do_stop process-129 0d.s3 166us : snd_dmaengine_pcm_trigger <-soc_pcm_trigger process-129 0d.s3 175us : ep93xx_dma_terminate_all <-snd_dmaengine_pcm_trigger process-129 0d.s3 182us : preempt_count_add <-ep93xx_dma_terminate_all process-129 0d.s4 189us*: m2p_hw_shutdown <-ep93xx_dma_terminate_all process-129 0d.s4 39472us : m2p_hw_setup <-ep93xx_dma_terminate_all ... rest skipped... process-129 0d.s. 40080us : <stack trace> => ep93xx_dma_tasklet => tasklet_action => __do_softirq => irq_exit => __handle_domain_irq => vic_handle_irq => __irq_usr => 0xb66c6668 Just abort the transfers and warn if the HW state is not what we expect. Move draining into device_synchronize callback. Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Please register or sign in to comment