Messages in this thread Patch in this message | | | Date | Thu, 05 Jun 2008 21:13:45 +0200 | From | Jaroslav Franek <> | Subject | [PATCH] sound: emu10k1 - fix system hang with Audigy2 ZS Notebook PCMCIA card |
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from: Jaroslav Franek
When the Linux kernel is compiled with CONFIG_DEBUG_SHIRQ=y, the Soundblaster Audigy2 ZS Notebook PCMCIA card causes the system hang during boot (udev stage) or when the card is hot-plug. The CONFIG_DEBUG_SHIRQ flag is by default 'y' with all Fedora kernels since 2.6.23. The problem was reported as https://bugzilla.redhat.com/show_bug.cgi?id=326411
The issue was hunted down to the snd_emu10k1_create() routine:
/* pseudo-code */ snd_emu10k1_create(...) { ... request_irq(... IRQF_SHARED ...) { register the irq handler #ifdef CONFIG_DEBUG_SHIRQ call the irq handler: snd_emu10k1_interrupt() { poll I/O port // <---- !! system hangs ... } #endif } ... snd_emu10k1_cardbus_init(...) { initialize I/O ports } ... }
The early access to I/O port in the interrupt handler causes the freeze. Obviously it is necessary to init the I/O ports before accessing them. This patch moves the registration of the irq handler after the initialization of the I/O ports.
Signed-off-by: Jaroslav Franek <jarin.franek@post.cz> --- This is the patch against 2.6.26-rc5. Please give it proper flaming, it is my first so I do not deserve much mercy ;).
--- a/sound/pci/emu10k1/emu10k1_main.c 2008-05-29 21:29:12.000000000 +0200 +++ b/sound/pci/emu10k1/emu10k1_main.c 2008-06-04 21:31:35.000000000 +0200 @@ -1818,13 +1818,6 @@ int __devinit snd_emu10k1_create(struct } emu->port = pci_resource_start(pci, 0); - if (request_irq(pci->irq, snd_emu10k1_interrupt, IRQF_SHARED, - "EMU10K1", emu)) { - err = -EBUSY; - goto error; - } - emu->irq = pci->irq; - emu->max_cache_pages = max_cache_bytes >> PAGE_SHIFT; if (snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, snd_dma_pci_data(pci), 32 * 1024, &emu->ptb_pages) < 0) { @@ -1887,6 +1880,14 @@ int __devinit snd_emu10k1_create(struct emu->fx8010.etram_pages.area = NULL; emu->fx8010.etram_pages.bytes = 0; + /* irq handler must be registered after I/O ports are activated */ + if (request_irq(pci->irq, snd_emu10k1_interrupt, IRQF_SHARED, + "EMU10K1", emu)) { + err = -EBUSY; + goto error; + } + emu->irq = pci->irq; + /* * Init to 0x02109204 : * Clock accuracy = 0 (1000ppm)
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