On 21 Jan 2022, at 16:53, Greg KH wrote:
On Fri, Jan 21, 2022 at 04:21:18PM +0800, Tianrui Wei wrote:
If there're not out of box solutions, is there a way I could view the API changes in every subsystem clearly? For example, this particular commit[^1] shows the second return argument is being removed from ki_complete, and it took a lot of fishing down the lkml to do. Perhaps there is a simpler way?
Use git itself to track the changes in apis. You can see all changes to a .h file by doing: git log -p path/to/file and then see where the api got changed.
This is a really good suggestion, and it's also the way I approach recent kernel modules. However some specifically ancient kernel modules is rather difficult to use this approach.
We have git history going back to Linux 0.1 so this should work. If not, then do the normal 'does it build' test. APIs are almost always changed in ways that break the build.
Thanks for the suggestion, I'll bear it in mind.
It usually isn't that difficult to forward port a driver, but it all depends on the age of the code, and what it actually does. Do you have a link to the code you wish to drag forward?
The specific driver I had in mind is a PCIE driver for a Xilinx IP block. It's under https://www.xilinx.com/products/boards-and-kits/ek-k7-kc705-g.html#resources in a zip folder called rdf0281-kc705-base-trd-2014-3.zip. Everyone with a xilinx account could download the folder. Unfortunately its header claims it contains confidential information from Xilinx, as such I'm a bit wary to post it online.
Please get support from xilix for stuff like this. You are paying for it from them, so please take advantage of it. Especially if they claim that their code is not GPLv2 compatible, you want them to take that legal risk, not you :)
Thanks! That makes a lot of sense.
greg k-h
Best Regards, Tianrui