MSI work being done

Chuck Tuffli is working on an implementation of MSI for DragonFly. MSI is a way for device drivers to talk, similar to but better than the old IRQ method. As Chuck kindly explained it to me, MSI and MSI-X are necessary for PCI-Express support.

2 Replies to “MSI work being done”

  1. One minor clarification. PCI-Express devices must support MSI or MSI-X, but that doesn’t mean an OS has to implement MSI(-X) to support PCIe devices. Many PCIe devices also emulate the legacy interrupt mode and thus can work with drivers and OS that know nothing about PCIe or MSI(-X).

  2. Hi Chuck, how does a device driver request and use MSI? Can you show me a sample code (if_em.c?). Thanks.

Comments are closed.

Your post must include a link to this post.

How does this work?
Write a response on your own website and include a link to this post. Then submit your response’s URL here. Your response may appear here after moderation. To update or remove it, edit or delete your original post and submit the same URL again. Learn more about Webmentions.