From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Liblit Date: Tue, 05 Oct 1999 09:32:03 +0000 Subject: harsh pop on Dell Precision 210 / Crystal audio Message-Id: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sound@vger.kernel.org I have a couple of Dell Precision 210 workstations with CS4236B sound chips. One is running Red Hat 6.1 and a self-built, unpatched kernel 2.2.12. It uses the following hand-tweaked module configuration: alias sound-slot-0 cs4232 alias sound-service-0-3 sound-slot-0 alias synth0 opl3 options cs4232 io=0x534 irq=5 dma=1 dma2=0 options opl3 io=0x388 The second box has Red Hat 6.0, including Red Hat's patched kernel 2.2.5. It uses the following module configuration, automatically generated by Red Hat's "sndconfig" tool: alias sound cs4232 pre-install sound insmod sound dmabuf=1 alias midi opl3 options opl3 io=0x388 options cs4232 io=0x534 irq=5 dma=1 dma2=0 \ mpuio=0x330 mpuirq=5 synthirq=-1 synthio=-1 In both cases, the IO/IRQ/DMA selections are also reflected in a PnP configuration file processed by "isapnp" at boot time. When any application starts to send sound to the chip, a loud and rather harsh "click" or "pop" comes out first. After that pop, sound continues to flow normally as long as the application keeps writing data. If the audio data flow stops, the pop will again appear the next time the audio data flow resumes. The pop appears when using either the "/dev/audio" or "/dev/dsp" interface, no matter what the overlying application: xmms, sox, esd, kwmsound, you name it. It does not appear, though, when using playmidi to play MIDI files through "/dev/sequencer". The pop even appears if I try to record sound rather than play it! "cat /dev/dsp >/dev/null" and "cat /dev/audio >/dev/null" both produce the pop. The pop is not associated with module loading. Even after the modules are loaded, each time an application starts to emit sound data, the introductory pop comes out first. The pop is not associated with simply opening "/dev/dsp" or "/dev/audio". The Enlightened sound daemon (esd) keeps "/dev/dsp" open the entire time it is running. But each time it plays a new sound clip, the harsh pop comes first. This ends up being particularly maddening when using a desktop configuration that plays accent sounds in response to user actions. "pop boing", "pop booda-booda", "pop whoosh" ... you get the picture. This does not appear to be a hardware failure, as both boxes suffer from the same problem. Furthermore, the IO/IRQ/DMA settings were copied from working Windows NT installations on the same boxes, and audio under NT does not exhibit this behavior. Any ideas?