[alsa-devel] [PATCH v2 00/11] drm/i915: LPE audio runtime PM and multipipe (v2)
Pierre-Louis Bossart
pierre-louis.bossart at linux.intel.com
Tue May 2 03:29:10 CEST 2017
On 04/28/2017 02:37 PM, Ville Syrjälä wrote:
> On Fri, Apr 28, 2017 at 12:10:31PM -0500, Pierre-Louis Bossart wrote:
>>
>> On 04/28/2017 03:41 AM, Takashi Iwai wrote:
>>> On Thu, 27 Apr 2017 18:02:19 +0200,
>>> ville.syrjala at linux.intel.com wrote:
>>>> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>>>
>>>> Okay, here's the second attempt at getting multiple pipes playing back
>>>> audio on the VLV/CHV HDMI LPE audio device. The main change from v1 is
>>>> that now the PCM devices are associated with ports instead of pipes,
>>>> so the audio from one device always gets output on the same display.
>>>>
>>>> I've also tacked on the alsa-lib conf update. No clue whether it's
>>>> really correct or not (the config language isn't a close friend
>>>> of mine).
>>>>
>>>> BTW I did notice that with LPE audio all the controls say iface=PCM,
>>>> whereas on HDA a bunch of them say iface=MIXER. No idea if that's
>>>> OK or not, just something I spotted when I was comparing the results
>>>> with HDA.
>>> We generally accept both iface types for IEC958 stuff, since
>>> historically many drivers have already mixed them up. So it's no
>>> problem :)
>>>
>>>
>>>> Entire series available here:
>>>> git://github.com/vsyrjala/linux.git lpe_audio_multipipe_2
>>>>
>>>> Cc: Takashi Iwai <tiwai at suse.de>
>>>> Cc: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
>>> All look good, and feel free to take my reviewed-by tag
>>> Reviewed-by: Takashi Iwai <tiwai at suse.de>
>>>
>>> As said previously, my only slight concern is the compatibility.
>>> But, in the current situation with PulseAudio, only few people would
>>> use this driver, so it shouldn't be so big impact, I suppose.
>>>
>>> BTW, which port is used in general on BYT/CHT?
>>>
>>> Oh, also, I suppose you want to carry these over i915 tree?
>>> I don't mind either way, I can take them through sound tree if
>>> preferred, too.
>> I see frequent oops on startup with this lpe_audio_multipipe_2 branch
>> with my CHT device not booting or no HDMI audio device created.
>> Not sure if these issues are due to the new patches or to the rest of
>> the drm code?
>>
>> [ 5.529023] BUG: unable to handle kernel NULL pointer dereference
>> at (null)
>> [ 5.529143] IP: hdmi_lpe_audio_probe+0x40f/0x650 [snd_hdmi_lpe_audio]
>> [ 5.529202] PGD 0
>>
>> [ 5.529242] Oops: 0000 [#1] SMP
>> [ 5.529274] Modules linked in: snd_soc_sst_atom_hifi2_platform
>> snd_soc_sst_match snd_soc_core snd_compress lpc_ich snd_seq
>> snd_seq_device shpchp snd_hdmi_lpe_audio(+) snd_pcm snd_timer dw_dmac
>> snd soundcore i2c_designware_platform(+) i2c_designware_core
>> spi_pxa2xx_platform acpi_pad mac_hid nfsd auth_rpcgss nfs_acl lockd
>> grace sunrpc ip_tables x_tables hid_generic mmc_block i2c_hid usbhid hid
>> autofs4
>> [ 5.529605] CPU: 2 PID: 512 Comm: systemd-udevd Not tainted
>> 4.11.0-rc8-test+ #11
>> [ 5.529671] Hardware name: ZOTAC XXXXXX/Cherry Trail FFD, BIOS 5.11
>> 09/28/2016
>> [ 5.529736] task: ffff88007485b780 task.stack: ffffc90000bfc000
>> [ 5.529793] RIP: 0010:hdmi_lpe_audio_probe+0x40f/0x650
>> [snd_hdmi_lpe_audio]
>> [ 5.529855] RSP: 0018:ffffc90000bffaf0 EFLAGS: 00010246
>> [ 5.529904] RAX: 0000000000000000 RBX: ffff880079209898 RCX:
>> ffff88007920f078
>> [ 5.529967] RDX: 0000000000000014 RSI: ffffc90000bffb28 RDI:
>> 0000000000000002
>> [ 5.530031] RBP: ffffc90000bffb70 R08: 0000000000000001 R09:
>> 0000000000000000
>> [ 5.530094] R10: ffff88007441bf00 R11: ffffc90000bffb36 R12:
>> ffff88007920ef20
>> [ 5.530159] R13: ffff88007920ef48 R14: 0000000000005688 R15:
>> 0000000000000047
>> [ 5.530225] FS: 00007f627c988640(0000) GS:ffff88007b300000(0000)
>> knlGS:0000000000000000
>> [ 5.530299] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 5.530352] CR2: 0000000000000000 CR3: 0000000078cb8000 CR4:
>> 00000000001006e0
>> [ 5.530416] Call Trace:
>> [ 5.530452] platform_drv_probe+0x3b/0xa0
>> [ 5.530494] driver_probe_device+0x2bb/0x460
>> [ 5.530538] __driver_attach+0xdf/0xf0
>> [ 5.530576] ? driver_probe_device+0x460/0x460
>> [ 5.530620] bus_for_each_dev+0x60/0xa0
>> [ 5.530658] driver_attach+0x1e/0x20
>> [ 5.530693] bus_add_driver+0x170/0x270
>> [ 5.530731] driver_register+0x60/0xe0
>> [ 5.530769] ? 0xffffffffa01cb000
>> [ 5.530803] __platform_driver_register+0x36/0x40
>> [ 5.530851] hdmi_lpe_audio_driver_init+0x17/0x1000 [snd_hdmi_lpe_audio]
>> [ 5.530915] do_one_initcall+0x43/0x180
>> [ 5.530956] ? __vunmap+0x81/0xd0
>> [ 5.530991] ? kfree+0x14c/0x160
>> [ 5.531024] ? kmem_cache_alloc_trace+0x38/0x150
>> [ 5.531070] do_init_module+0x5f/0x1f8
>> [ 5.531108] load_module+0x271e/0x2bd0
>> [ 5.531147] ? kernel_read_file+0x1a3/0x1c0
>> [ 5.531188] SYSC_finit_module+0xbc/0xf0
>> [ 5.531226] ? SYSC_finit_module+0xbc/0xf0
>> [ 5.531267] SyS_finit_module+0xe/0x10
>> [ 5.531305] do_syscall_64+0x6e/0x180
>> [ 5.531345] entry_SYSCALL64_slow_path+0x25/0x25
>> [ 5.531389] RIP: 0033:0x7f627b5fbbf9
>> [ 5.531424] RSP: 002b:00007ffe053eee68 EFLAGS: 00000246 ORIG_RAX:
>> 0000000000000139
>> [ 5.531493] RAX: ffffffffffffffda RBX: 000055d6c745b690 RCX:
>> 00007f627b5fbbf9
>> [ 5.531558] RDX: 0000000000000000 RSI: 00007f627c134995 RDI:
>> 0000000000000007
>> [ 5.531622] RBP: 00007f627c134995 R08: 0000000000000000 R09:
>> 00007ffe053eef80
>> [ 5.531687] R10: 0000000000000007 R11: 0000000000000246 R12:
>> 0000000000000000
>> [ 5.531751] R13: 000055d6c7459ae0 R14: 0000000000020000 R15:
>> 000055d6c745b690
>> [ 5.531816] Code: 48 8b 45 b0 8b 48 18 e8 e0 cb 22 e1 49 8b 44 24 28
>> 4a 8d 8c 33 58 01 00 00 48 8d 75 b8 45 31 c9 41 b8 01 00 00 00 ba 14 00
>> 00 00 <48> 8b 38 e8 a9 2a ff ff 85 c0 0f 88 09 01 00 00 49 8b 84 24 58
> Disassembling that I get:
>
> 4005a0: 48 8b 45 b0 mov -0x50(%rbp),%rax
> 4005a4: 8b 48 18 mov 0x18(%rax),%ecx
> 4005a7: e8 e0 cb 22 e1 callq ffffffffe162d18c <_end+0xffffffffe102c14c>
> 4005ac: 49 8b 44 24 28 mov 0x28(%r12),%rax
> 4005b1: 4a 8d 8c 33 58 01 00 lea 0x158(%rbx,%r14,1),%rcx
> 4005b8: 00
> 4005b9: 48 8d 75 b8 lea -0x48(%rbp),%rsi
> 4005bd: 45 31 c9 xor %r9d,%r9d
> 4005c0: 41 b8 01 00 00 00 mov $0x1,%r8d
> 4005c6: ba 14 00 00 00 mov $0x14,%edx
> 4005cb: 48 8b 38 mov (%rax),%rdi
> 4005ce: e8 a9 2a ff ff callq 3f307c <_init-0xd32c>
> 4005d3: 85 c0 test %eax,%eax
> 4005d5: 0f 88 09 01 00 00 js 4006e4 <__GNU_EH_FRAME_HDR+0x100>
> 4005db: 49 rex.WB
> 4005dc: 8b .byte 0x8b
> 4005dd: 84 24 58 test %ah,(%rax,%rbx,2)
>
> Comparing that with the disassembly from my build, that
> first call looks like the snprintf() and the second one would
> then be snd_jack_new(). So it seems to blow in the
> ctx->card_ctx->card dereference. But I don't really see how
> a NULL pointer could sneak in there.
There was an standard PORT_B off-by-one error which resulted in memory
corruption. the patch below seems to fix the problem, I can get the same
functionality as before with concurrent playback on HDMI and DP, and the
jack values are correctly set.
diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c
b/drivers/gpu/drm/i915/intel_lpe_audio.c
index fa728ed..3bf6528 100644
--- a/drivers/gpu/drm/i915/intel_lpe_audio.c
+++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
@@ -332,7 +332,7 @@ void intel_lpe_audio_notify(struct drm_i915_private
*dev_priv,
return;
pdata = dev_get_platdata(&dev_priv->lpe_audio.platdev->dev);
- ppdata = &pdata->port[port];
+ ppdata = &pdata->port[port - PORT_B];
spin_lock_irqsave(&pdata->lpe_audio_slock, irqflags);
@@ -359,7 +359,7 @@ void intel_lpe_audio_notify(struct drm_i915_private
*dev_priv,
}
if (pdata->notify_audio_lpe)
- pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port);
+ pdata->notify_audio_lpe(dev_priv->lpe_audio.platdev, port - PORT_B);
spin_unlock_irqrestore(&pdata->lpe_audio_slock, irqflags);
}
diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c
index 909391d..0153439 100644
--- a/sound/x86/intel_hdmi_audio.c
+++ b/sound/x86/intel_hdmi_audio.c
@@ -1579,7 +1579,7 @@ static irqreturn_t
display_pipe_interrupt_handler(int irq, void *dev_id)
static void notify_audio_lpe(struct platform_device *pdev, int port)
{
struct snd_intelhad_card *card_ctx = platform_get_drvdata(pdev);
- struct snd_intelhad *ctx = &card_ctx->pcm_ctx[port];
+ struct snd_intelhad *ctx = &card_ctx->pcm_ctx[port]; /* warning:
offset with -PORT_B */
schedule_work(&ctx->hdmi_audio_wq);
}
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