Gerd Knorr wrote: > ...you can vmalloc() a chunk of memory and then remap that to > userspace (like most drivers do today). For which v4l2_vmalloc_to_page() is still useful. (Thanks for the memory management tutorial.) > > > How do I setup a second, independent stream? > > > > second stream has be a different V4L2_BUF_TYPE. > > Another type. That will work, ok. /me was thinking about two capture > streams... Two capture streams can be done if the driver adds a second capture stream type, e.g. V4L2_BUF_TYPE_CAPTURE2. > Idea was to make it easier to handle v4l1 backward compatibility. I understand, but I disagree that that is a valid reason to change the API. It doesn't add new capability, provide a benefit to the application, or solve an API design defect. > I don't find it useful to have locked every single list operation. > [...] > The irq handler may have to handle multiple list operations, and > in needs to do more stuff (hardware programming) with the lock. I used different locks for hardware and lists. One lock for each list, and one lock for each card. Bill.
