From: Lauri Kasanen <cand@gmx.com>
To: Takashi Iwai <tiwai@suse.de>
Cc: linux-mips@vger.kernel.org, tsbogend@alpha.franken.de, perex@perex.cz
Subject: Re: [PATCH 5/6 v2] sound: Add n64 driver
Date: Sun, 10 Jan 2021 19:03:32 +0200 [thread overview]
Message-ID: <20210110190332.8a818e931975f02b8f3d3881@gmx.com> (raw)
In-Reply-To: <s5hwnwlum21.wl-tiwai@suse.de>
On Sun, 10 Jan 2021 11:24:22 +0100
Takashi Iwai <tiwai@suse.de> wrote:
> > At first there was no nextpos, and _pointer() always reported pos. This
> > didn't work, the core played through the audio at chipmunk speed. So
> > there must be more that I don't understand here.
>
> Try to set the periods_min=2 and the integer periods hw constraint at
> first, and change the pointer callback to return nextpos. Also, at
> the push function, set runtime->delay = period_size as well.
When I do all this, it still causes the chipmunk speed. Several seconds
of audio gets played in 0.3s or so. Sorry if this is taking too much of
your time, I'm a bit lost here at what the alsa core is expecting.
Printks show the following repeats:
start, period size 1024
push, bool irq=0
irq fired
push, bool irq=1
pointer at 8192
stop
It stops and starts again for some reason. This does not happen in the
current pos/nextpos implementation.
> > - the DMA unit has errata if (start + len) & 0x3fff == 0x2000, this
> > must never happen
>
> Ditto.
Can it really handle a constraint this complex? That'd be impressive.
It'd remove the memcpy need if so.
> > - the audio IRQ is not a timer, it fires when the card's internal
> > buffers are empty and need immediate refill
>
> It's the current implementation, right?
Yes, but I was wondering if a different setup would work better. The
alsa setup is a bit confusing to me still.
- Lauri
next prev parent reply other threads:[~2021-01-10 17:04 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-08 8:35 [PATCH 5/6 v2] sound: Add n64 driver Lauri Kasanen
2021-01-08 9:06 ` Takashi Iwai
2021-01-08 10:13 ` Lauri Kasanen
2021-01-09 7:23 ` Lauri Kasanen
2021-01-09 8:16 ` Takashi Iwai
2021-01-09 17:46 ` Lauri Kasanen
2021-01-09 18:17 ` Takashi Iwai
2021-01-09 20:54 ` Takashi Iwai
2021-01-10 7:15 ` Lauri Kasanen
2021-01-10 10:24 ` Takashi Iwai
2021-01-10 17:03 ` Lauri Kasanen [this message]
2021-01-10 17:22 ` Takashi Iwai
2021-01-10 17:41 ` Lauri Kasanen
2021-01-11 8:05 ` Takashi Iwai
2021-01-11 9:43 ` Lauri Kasanen
2021-01-11 10:11 ` Takashi Iwai
2021-01-11 12:02 ` Lauri Kasanen
2021-01-11 15:25 ` Takashi Iwai
2021-01-11 15:51 ` Lauri Kasanen
2021-01-13 11:57 ` Lauri Kasanen
2021-01-13 12:04 ` Takashi Iwai
2021-01-13 12:14 ` Lauri Kasanen
2021-01-13 12:38 ` Takashi Iwai
2021-01-13 12:49 ` Lauri Kasanen
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