On Fri, Apr 14, 2017 at 05:35:29PM +0300, Alexander Kochetkov wrote: > The patch solve the I2S click problem on rk3188. Actually > all the devices using pl330 should have I2S click problem > due to pl330 cyclic transfer implementation. > > Current implementation depends on soft irq. If pl330 unable > to submit next transfer in time some samples could be lost. > The lost samples heard as sound click. In order to check > lost samples, I've installed I2S interrupt handler to signal > overflow/underflow conditions. Sometimes I saw overflow > or underflow events and heard clicks. > > The patch setup cyclic transfer such a way, that transfer can > run infinitely without CPU intervention. As a result, > lost samples and clicks gone. > > Signed-off-by: Alexander Kochetkov <al.koc...@gmail.com> > --- > drivers/dma/pl330.c | 192 > +++++++++++++++++++++++++-------------------------- > 1 file changed, 94 insertions(+), 98 deletions(-) >
I didn't look at the code but testing fails. HW: Odroid U3 (Exynos4412), pl330 used for dma for i2s, max98090 audio codec SW: 4.11.0-rc6-next-20170413 Only first aplay workes fine. After it, the next sound stalls: [ 170.059271] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 170.059441] 1-...: (1 GPs behind) idle=11e/140000000000000/0 softirq=2335/2335 fqs=1049 [ 170.067474] (detected by 3, t=2102 jiffies, g=459, c=458, q=194) [ 170.073555] Sending NMI from CPU 3 to CPUs 1: [ 180.083093] rcu_preempt kthread starved for 999 jiffies! g459 c458 f0x0 RCU_GP_DOING_FQS(4) ->state=0x0 [ 180.086848] rcu_preempt S 0 8 2 0x00000000 [ 180.092344] [<c073e150>] (__schedule) from [<c073e4dc>] (schedule+0x4c/0xac) [ 180.099353] [<c073e4dc>] (schedule) from [<c0742634>] (schedule_timeout+0x14c/0x23c) [ 180.107081] [<c0742634>] (schedule_timeout) from [<c01702f4>] (rcu_gp_kthread+0x5dc/0x94c) [ 180.115330] [<c01702f4>] (rcu_gp_kthread) from [<c01381f0>] (kthread+0x124/0x154) [ 180.122793] [<c01381f0>] (kthread) from [<c0108438>] (ret_from_fork+0x14/0x3c) Let me know if you need more data. I wonder why you haven't experience this? Best regards, Krzysztof
