[alsa-devel] MIDI on ice1724 - real-time kernel problem

[Takashi Iwai]

At Thu, 15 May 2008 09:21:02 +0200,
Clemens Ladisch wrote:
> 
> Pavel Hofman wrote:
> > Actually, when does the MPU_TX interrupt get thrown? Upon exhausting
> > some output buffer?
> 
> According to the datasheet, when the number of bytes in the TX FIFO goes
> below the watermark value (for some unspecified value of "below").
> 
> Is there a reason why the watermarks are set to 1 and not to 0?

We got TX IRQ storm when it was 0, according to Pavel.

> Anyway, this hardware is not compatible with the MPU-401, so we should
> not try to twist the MPU-401 code into working with it.

Agreed.  I thought it's enough similar to the real MPU401, but it's
getting nastier.


thanks,

Takashi