Re: 3.4.4: disabling irq
On Sat, 29 Dec 2012, Udo van den Heuvel wrote: > Hello Alan, > > On 2012-12-02 18:38, Alan Stern wrote: > > Try this patch instead. > > The patch works OK for the first few times: > > ohci_hcd :00:13.0: last IRQ repeated 22 times > ohci_hcd :00:13.0: IRQ: 24 805a Can you provide the entire output? Two lines isn't enough. > After that it never prints anything anymore. > > The irq issue still occurs. How can we fix this? Does the IRQ problem occur immediately after the last line from the patch? I really need to see the entire log to tell what's happening. Also, you should turn on CONFIG_PRINTK_TIME so that the log entries will have timestamps. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: 3.4.4: disabling irq
Hello Alan, On 2012-12-31 18:24, Alan Stern wrote: >> The patch works OK for the first few times: >> >> ohci_hcd :00:13.0: last IRQ repeated 22 times >> ohci_hcd :00:13.0: IRQ: 24 805a > > Can you provide the entire output? Two lines isn't enough. It's just the normal bootup, then the two usb lines, and then nothing more related until the irq problem occurs. Then there's loads of pwc frame errors until I find out and correct the situation a bit. >> The irq issue still occurs. How can we fix this? > Does the IRQ problem occur immediately after the last line from the > patch? Nope. The lines are printed after bootup and then it can take hours. Kind regards, Udo -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
usb audio popping on low cpu speed device
Hi list, I've been looking into an issue wherein a cheap usb sound card [1] plugged into a host system with a 400MHz mips core [2] makes audible popping noises, at a rate of up to a few times per second. I don't believe the problem is at the application or alsa layers, as I don't get underflow errors. I'm running a 3.3.8 kernel from openwrt. The usb host uses the ehci driver. The sound card uses the snd-usb-audio driver. This only happens when the wifi built into the chip is enabled, and wifi traffic is occuring. If I disable it there are no audible pops. A different cheap usb sound card produces less pop noises, but it still makes them. My theory is that the wifi processing throws off the timing for the usb driver, so sometimes the isochronous schedule and data is not updated in time for the next usb frame. My understanding of usb/ehci is limited as I have only read the spec this weekend so I could be way off base. I might also be having a hardware/electrical issue rather than software/kernel. Any tips or advice appreciated. I can provide usbmon output for popping and non-popping cases. I also have audio recordings, and usb analyzer traces. The analyzer trace shows partial packets arriving during pops, with the rest arriving 200us later. There were sometimes other errors as well (sorry I don't have the analyzer trace on this machine). [1] http://www.amazon.com/Syba-SD-CM-UAUD-Adapter-C-Media-Chipset/dp/B001MSS6CS [2] http://wiki.openwrt.org/toh/tp-link/tl-mr3020 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
