At Mon, 10 Mar 2008 11:59:04 +0800, Saurav SAHU wrote: > > Hi all > > The platform on which I am trying to perform ALSA playback and record with > USB sound device is based on a MIPS CPU running Linux kernel 2.6.14. The > kernel uses non-coherent DMA in the configuration: > CONFIG_DMA_NONCOHERENT=y > CONFIG_DMA_NEED_PCI_MAP_STATE=y > CONFIG_CPU_BIG_ENDIAN=y > CONFIG_SYS_SUPPORTS_BIG_ENDIAN=y > CONFIG_BOOT_ELF32=y > CONFIG_MIPS_L1_CACHE_SHIFT=5 > I have attached the kernel .config file for further information. So far, I > have not succeeded in hearing sound with 'aplay', or capturing sound with > 'arecord'. > > If there have been any similar issues reported on ALSA usage with MIPS CPU > based on non-coherent DMA in the past, please let me know. Also, if there > have been any patches developed for successful resolution of this issue on > similar platform/configuration, it would be very useful for me.
Yes, there is a known long-standing problem wrt cache coherency. Try to disable the mmap support in the driver as a test. Takashi > > Thanks & Regards > Saurav > > ----- Original Message ----- > From: Saurav Sahu > To: alsa-user@lists.sourceforge.net > Sent: Friday, March 07, 2008 4:33 PM > Subject: Re: ALSA utility aplay/arecord error > > > I have been able to resolve the previously reported errors by setting the > environment variable for ALSA configuration file on the target filesystem of > the embedded platform. > > However, I do not hear any audio from USB sound device with speaker-test or > aplay: > > Upon using arecord for recording, I get an error: > > Is this problem related to a low-level driver issue which may not be > working well on target platform? Could there be a DMA related issue as the > samples don't seem to be transferred to the USB audio device. > > > ----- Original Message ----- > From: Saurav Sahu > To: alsa-user@lists.sourceforge.net > Sent: Thursday, March 06, 2008 4:28 PM > Subject: ALSA utility aplay/arecord error > > > Hello > > I am working towards using ALSA for playback and capture on an embedded > platform running Linux. The kernel uses ALSA driver version 1.0.10rc1. I had > manually built and installed ALSA library (v1.0.10) and ALSA utilities > (v1.0.10) for the target platform filesystem. I have a USB audio device > (C-Media) connected to the USB port of the board and it seems to be > successfully successfully detected by the driver. > > However, when I run ALSA utilities like aplay, arecord or speaker-test, I > observe errors opening the hardware device which may be related to the > configuration on the filesystem. > > Are these errors from ALSA utility/library due to the detection of > hardware, ALSA configuration files or something else related to my target > device filesystem? > > Thanks in advance for any help. Do let me know if you need any more > details. > > Best Regards > Saurav ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Alsa-user mailing list Alsa-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/alsa-user
