At Tue, 20 May 2008 11:03:42 -0500, Timur Tabi wrote:
-------- Original Message -------- Subject: RE: Regarding MPC8610 BSP question and issue Date: Tue, 20 May 2008 08:55:46 -0700 From: Hayasaka Manabu manabu.hayasaka@freescale.com To: Hayasaka Manabu manabu.hayasaka@freescale.com, Johnson Kelly Kelly.Johnson@freescale.com CC: sun york yorksun@freescale.com, Namiki Ayumi namiki@freescale.com, Beck Glenn Glenn.Beck@freescale.com, Cox Kevin K.Cox@freescale.com, Hamano Masahiro M.Hamano@freescale.com, Tabi Timur timur@freescale.com References: E03EE6E38549E949AE8138F60493E1E801C49A0C@zja67exm20.fsl.freescale.net 4807899D.3000901@freescale.com E03EE6E38549E949AE8138F60493E1E801DA1B11@zja67exm20.fsl.freescale.net 48110FCF.7070302@freescale.com BD243C8D8F65694A966948E9D51F9815C29409@zja67exm21.fsl.freescale.net 48189540.9060309@freescale.com BD243C8D8F65694A966948E9D51F9815C29422@zja67exm21.fsl.freescale.net E03EE6E38549E949AE8138F60493E1E801DA25D9@zja67exm20.fsl.freescale.net 4821CA02.2020504@freescale.com E03EE6E38549E949AE8138F60493E1E801FA11C8@zja67exm20.fsl.freescale.net 4829C444.7010206@freescale.com E03EE6E38549E949AE8138F60493E1E801FA13D2@zja67exm20.fsl.freescale.net 482B1D10.7090402@freescale.com 482B2699.8020409@freescale.com
I'm working with a customer that has discovered a possible problem with OSS emulation. Unfortunately, I don't have a lot of experience with OSS, so I need help understanding whether the customer's observations point to a real problem or not.
The customer is using an old application called "bplay" to test OSS audio support on our hardware. The application works fine on x86, but fails on our PowerPC board. It could be an endian issue, but I doubt it.
Here is the forwarded email (slightly edited). Can someone familiar with the OSS "sync" functionality comment?
They reported that it seemed some ioctl commands in the OSS emulation did not work correctly.
The tested procedure of the ioctl commands are as following,
#1) Stopped audio stream output after doing followings:
- Opening /dev/mixer
- Getting a channel value (0x00000001) that is used for "ioctl(fd,
SOUND_MIXER_READ_DEVMASK, &Sndsts);". 3. Write audio volume information by "ioctl(fd, SOUND_MIXER_WRITE_VOLUME, &Value);",
This looks weird. The mixer ioctl is independent from the PCM, basically.
#2) Stopped audio stream output after doing following:
- Opening /dev/dsp
- Executing command "ioctl(fd, SNDCTL_DSP_SYNC, NULL);",
The sync ioctl is to block the operation until all samples are played. But, it's a bit strange that the stream stops after this. It should be an underrun instead (and OSS recovers by itself).
Takashi
XXXX found that by commenting out the "sync_audio" function on the source code of "bplay" made "bplay" work. So XXXX suspects the implementation of the ioctl on the OSS emulation may have a problem.
-- Timur Tabi Linux kernel developer at Freescale _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel