At some point, typically after calling snd_device_new(), you need to register the struct device of the chip you're handling for udev and co. ALSA provides a macro for compatibility with older kernels. Simply call like the following:

  snd_card_set_dev(card, &pci->dev);

          

so that it stores the PCI's device pointer to the card. This will be referred by ALSA core functions later when the devices are registered.

In the case of non-PCI, pass the proper device struct pointer of the BUS instead. (In the case of legacy ISA without PnP, you don't have to do anything.)