Re: [alsa-devel] [PATCH 2/3] ASoC: DaVinci: pcm, rename variables in prep for ping/pong

[Caglar Akyuz <caglarakyuz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Wednesday 09 September 2009 15:08:42 Nori, Sekhar wrote:
> On Fri, Sep 04, 2009 at 00:25:57, Troy Kisky wrote:
> > Nori, Sekhar wrote:
> > > On Thu, Sep 03, 2009 at 05:45:08, Troy Kisky wrote:
> > >> Mark Brown wrote:
> > >>> On Mon, Aug 31, 2009 at 04:31:44PM -0700, Troy Kisky wrote:
> > >
> > > [...]
> > >
> > >>> I'll probably also apply the first patch since nobody else seems to
> > >>> care one way or another, but I would urge you to look at changing the
> > >>> default for the platform data to at most select the workaround only
> > >>> on CPUs that have problems with channel swapping - it's going to
> > >>> cause confusion for people to have it on by default.
> > >>
> > >> I think the ones without a problem use davinci-mcasp instead of
> > >> davinci-i2s but share davinci-pcm. So, I don't know of any machines to
> > >> exclude in davinci-i2s. But if someone else knows, speak up.
>
> [...]
>
> > > Using EDMA acount=4 instead of 2 (32-bit transfers) did fix that issue
> > > on the OSS drivers but I don't recall the problem morphing into an
> > > "always channel swapped" case.
> > >
> > > Have you tested your patch (1/3) with DM644x EVM? If not, we can do
> > > that and see if it leads to channels being always swapped on that
> > > hardware as well.
> >
> > Yes, I have tested with dm644x, not evm. I haven't tried to hear the
> > channel swap, but I have no doubt that it is.
>
> I finally got around to testing your patch 1/3 on DM6446 EVM.
>
> Without your patch, channel swap is quite easy to reproduce using audio
> loopback:
>
> arecord -fcd | aplay -fcd
>
> The audio source is a PC which speaker balance set to an extreme.
> By starting and stopping this command repeatedly, you can see the audio
> moving from one channel to the other.
>
> Applying your patch fixes this issue.
>
> Also, I did not notice any permanent channel swap. Used aplay to play data
> which was first left-only and then right-only. Plays the same way on a
> Linux PC.
>
> I will test on couple of other platform using davinci-i2s (DM355 etc)
> before acking the patch.
>
> However, with or without your patch, I noticed a segmentation fault for the
> first time the 'arecord | aplay' loop is created. There is no fault the
> second time around. I haven't spent time debugging this yet.
>

This is due to these lines in davinci_pcm_enqueue_dma:

	data_type = prtd->params->data_type;	
	count = period_size / data_type;

First time running data_type is set to 0. This is a long time issue, I 
remember modifying my kernels to check for zero before this division..

Regards,
Caglar

> root@arago:~# arecord -fcd | aplay -fcd
> Recording WAVE 'stdin' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
> Division by zero in kernel.
> Backtrace:
> [<c002b784>] (dump_backtrace+0x0/0x114) from [<c0248cf0>]
> (dump_stack+0x18/0x1c) r7:86a60000 r6:c77cdae0 r5:00000040 r4:00000000
> [<c0248cd8>] (dump_stack+0x0/0x1c) from [<c002b8cc>] (__div0+0x18/0x20)
> [<c002b8b4>] (__div0+0x0/0x20) from [<c014b0fc>] (Ldiv0+0x8/0x10)
> [<c01bad64>] (davinci_pcm_enqueue_dma+0x0/0x110) from [<c01baea0>]
> (davinci_pcm_ prepare+0x2c/0x58)
> [<c01bae74>] (davinci_pcm_prepare+0x0/0x58) from [<c01b5260>]
> (soc_pcm_prepare+0 x84/0x184)
>  r7:c030df38 r6:c030d1b8 r5:c70d3900 r4:00000000
> [<c01b51dc>] (soc_pcm_prepare+0x0/0x184) from [<c01aac3c>]
> (snd_pcm_do_prepare+0 x1c/0x34)
> [<c01aac20>] (snd_pcm_do_prepare+0x0/0x34) from [<c01aa87c>]
> (snd_pcm_action_sin gle+0x40/0x7c)
>  r5:c70d3900 r4:c030cbc8
> [<c01aa83c>] (snd_pcm_action_single+0x0/0x7c) from [<c01abd80>]
> (snd_pcm_action_ nonatomic+0x58/0x70)
>  r7:c70d3900 r6:00000002 r5:c030cbc8 r4:c70d3900
> [<c01abd28>] (snd_pcm_action_nonatomic+0x0/0x70) from [<c01ae2cc>]
> (snd_pcm_comm on_ioctl1+0x814/0x1308)
>  r7:c70d3900 r6:0002a690 r5:0002a690 r4:c77b6c80
> [<c01adab8>] (snd_pcm_common_ioctl1+0x0/0x1308) from [<c01af20c>]
> (snd_pcm_captu re_ioctl1+0x44c/0x470)
> [<c01aedc0>] (snd_pcm_capture_ioctl1+0x0/0x470) from [<c01af268>]
> (snd_pcm_captu re_ioctl+0x38/0x3c)
>  r7:c77b6c80 r6:00004140 r5:0002a690 r4:c77b6c80
> [<c01af230>] (snd_pcm_capture_ioctl+0x0/0x3c) from [<c00a2680>]
> (vfs_ioctl+0x34/ 0x94)
> [<c00a264c>] (vfs_ioctl+0x0/0x94) from [<c00a2d44>]
> (do_vfs_ioctl+0x56c/0x5c8) r7:c77b6c80 r6:00000004 r5:c77b6c80 r4:c6b8c8a8
> [<c00a27d8>] (do_vfs_ioctl+0x0/0x5c8) from [<c00a2de0>]
> (sys_ioctl+0x40/0x64) [<c00a2da0>] (sys_ioctl+0x0/0x64) from [<c0027ea0>]
> (ret_fast_syscall+0x0/0x2c) r7:00000036 r6:bec987d8 r5:0002a468 r4:000b567f
> Division by zero in kernel.
> Backtrace:
> [<c002b784>] (dump_backtrace+0x0/0x114) from [<c0248cf0>]
> (dump_stack+0x18/0x1c) r7:86a62000 r6:c77cdae0 r5:00000040 r4:00000000
> [<c0248cd8>] (dump_stack+0x0/0x1c) from [<c002b8cc>] (__div0+0x18/0x20)
> [<c002b8b4>] (__div0+0x0/0x20) from [<c014b0fc>] (Ldiv0+0x8/0x10)
> [<c01bad64>] (davinci_pcm_enqueue_dma+0x0/0x110) from [<c01baec0>]
> (davinci_pcm_ prepare+0x4c/0x58)
> [<c01bae74>] (davinci_pcm_prepare+0x0/0x58) from [<c01b5260>]
> (soc_pcm_prepare+0 x84/0x184)
>  r7:c030df38 r6:c030d1b8 r5:c70d3900 r4:00000000
> [<c01b51dc>] (soc_pcm_prepare+0x0/0x184) from [<c01aac3c>]
> (snd_pcm_do_prepare+0 x1c/0x34)
> [<c01aac20>] (snd_pcm_do_prepare+0x0/0x34) from [<c01aa87c>]
> (snd_pcm_action_sin gle+0x40/0x7c)
>  r5:c70d3900 r4:c030cbc8
> [<c01aa83c>] (snd_pcm_action_single+0x0/0x7c) from [<c01abd80>]
> (snd_pcm_action_ nonatomic+0x58/0x70)
>  r7:c70d3900 r6:00000002 r5:c030cbc8 r4:c70d3900
> [<c01abd28>] (snd_pcm_action_nonatomic+0x0/0x70) from [<c01ae2cc>]
> (snd_pcm_comm on_ioctl1+0x814/0x1308)
>  r7:c70d3900 r6:0002a690 r5:0002a690 r4:c77b6c80
> [<c01adab8>] (snd_pcm_common_ioctl1+0x0/0x1308) from [<c01af20c>]
> (snd_pcm_captu re_ioctl1+0x44c/0x470)
> [<c01aedc0>] (snd_pcm_capture_ioctl1+0x0/0x470) from [<c01af268>]
> (snd_pcm_captu re_ioctl+0x38/0x3c)
>  r7:c77b6c80 r6:00004140 r5:0002a690 r4:c77b6c80
> [<c01af230>] (snd_pcm_capture_ioctl+0x0/0x3c) from [<c00a2680>]
> (vfs_ioctl+0x34/ 0x94)
> [<c00a264c>] (vfs_ioctl+0x0/0x94) from [<c00a2d44>]
> (do_vfs_ioctl+0x56c/0x5c8) r7:c77b6c80 r6:00000004 r5:c77b6c80 r4:c6b8c8a8
> [<c00a27d8>] (do_vfs_ioctl+0x0/0x5c8) from [<c00a2de0>]
> (sys_ioctl+0x40/0x64) [<c00a2da0>] (sys_ioctl+0x0/0x64) from [<c0027ea0>]
> (ret_fast_syscall+0x0/0x2c) r7:00000036 r6:bec987d8 r5:0002a468 r4:000b567f
> Division by zero in kernel.
> Playing WAVE 'stBacktrace: din' : Signed 16
>  bit Little Endi[<c002b784>] an, Rate 44100 H(dump_backtrace+0x0/0x114) z,
> Stere o
> from [<c0248cf0>] (dump_stack+0x18/0x1c)
>  r7:86a64000 r6:c77cdae0 r5:00000040 r4:00000000
> [<c0248cd8>] (dump_stack+0x0/0x1c) from [<c002b8cc>] (__div0+0x18/0x20)
> [<c002b8b4>] (__div0+0x0/0x20) from [<c014b0fc>] (Ldiv0+0x8/0x10)
> [<c01bad64>] (davinci_pcm_enqueue_dma+0x0/0x110) from [<c01bb0bc>]
> (davinci_pcm_ dma_irq+0x58/0x80)
> [<c01bb064>] (davinci_pcm_dma_irq+0x0/0x80) from [<c0031904>]
> (dma_irq_handler+0 xec/0x12c)
>  r5:00000003 r4:00000004
> [<c0031818>] (dma_irq_handler+0x0/0x12c) from [<c0068ee8>]
> (handle_IRQ_event+0x4 4/0x114)
> [<c0068ea4>] (handle_IRQ_event+0x0/0x114) from [<c006ab74>]
> (handle_edge_irq+0x1 48/0x1b4)
>  r7:c7007440 r6:00000010 r5:c02ff060 r4:c6baa000
> [<c006aa2c>] (handle_edge_irq+0x0/0x1b4) from [<c0027070>]
> (_text+0x70/0x8c) r7:00000002 r6:00000800 r5:00000000 r4:00000010
> [<c0027000>] (_text+0x0/0x8c) from [<c0027aac>] (__irq_svc+0x4c/0x90)
> Exception stack(0xc6babdf0 to 0xc6babe38)
> bde0:                                     00000001 00000000 c6baa000
> 40000013 be00: 00000800 c76f2800 00000800 c70d3900 00000000 00000800
> 00000000 c6babe8c be20: c6baa000 c6babe38 c01b16f4 c01b1714 40000013
> ffffffff
>  r5:fec48000 r4:ffffffff
> [<c01b1548>] (snd_pcm_lib_read1+0x0/0x30c) from [<c01b1934>]
> (snd_pcm_lib_read+0 x60/0x6c)
> [<c01b18d4>] (snd_pcm_lib_read+0x0/0x6c) from [<c01aee8c>]
> (snd_pcm_capture_ioct l1+0xcc/0x470)
>  r6:bec98ab4 r5:bec98ab4 r4:00000000
> [<c01aedc0>] (snd_pcm_capture_ioctl1+0x0/0x470) from [<c01af268>]
> (snd_pcm_captu re_ioctl+0x38/0x3c)
>  r7:c77b6c80 r6:800c4151 r5:bec98ab4 r4:c77b6c80
> [<c01af230>] (snd_pcm_capture_ioctl+0x0/0x3c) from [<c00a2680>]
> (vfs_ioctl+0x34/ 0x94)
> [<c00a264c>] (vfs_ioctl+0x0/0x94) from [<c00a2d44>]
> (do_vfs_ioctl+0x56c/0x5c8) r7:c77b6c80 r6:00000004 r5:c77b6c80 r4:c6b8c8a8
> [<c00a27d8>] (do_vfs_ioctl+0x0/0x5c8) from [<c00a2de0>]
> (sys_ioctl+0x40/0x64) [<c00a2da0>] (sys_ioctl+0x0/0x64) from [<c0027ea0>]
> (ret_fast_syscall+0x0/0x2c) r7:00000036 r6:00000000 r5:0002a4b8 r4:0002a468
> arecord: pcm_read:1529: read error: Input/output error
> root@arago:~#
>
> Thanks,
> Sekhar
>
> > > One feedback we have received on this solution is that it does not work
> > > for 24-bit audio. In which case, implementing the workaround described
> > > in the errata is the only way around.
> >
> > Yes, you cannot shift more than 32 bits at once, so 48 bits is out.
> > Although 24 bit format would be easy to add, currently only 8, 16, and 32
> > are supported by davinci-i2s.
> >
> > > Thanks,
> > > Sekhar
>
> _______________________________________________
> Davinci-linux-open-source mailing list
> Davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org
> http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source