-stable review patch. If anyone has any objections, please let us know. ------------------ From: Jaroslav Franek upstream commit: 868e15dbd2940f9453b4399117686f408dc77299 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 Acked-by: James Courtier-Dutton Signed-off-by: Takashi Iwai Signed-off-by: Chris Wright --- sound/pci/emu10k1/emu10k1_main.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/sound/pci/emu10k1/emu10k1_main.c +++ b/sound/pci/emu10k1/emu10k1_main.c @@ -1817,13 +1817,6 @@ 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) { @@ -1886,6 +1879,14 @@ 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) -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/