Thanks for the tips, and they may work for other HP DV4 owners as a workaround, but they don't do anything for my machine. Something has still changed with snd_hda_intel between alsa 1.0.17 and 1.0.20 or kernel 2.6.27 and 2.6.28 (or both) that broke the proper PCI and/or IRQ grabbing on my machine.
Thanks for the tips, and they may work for other HP DV4 owners as a workaround, but they don't do anything for my machine. Something has still changed with snd_hda_intel between alsa 1.0.17 and 1.0.20 or kernel 2.6.27 and 2.6.28 (or both) that broke the proper PCI and/or IRQ grabbing on my machine.