After a kick in the pants from the leader of the Linux driver project, Microsoft has resumed work on its historic driver code submission to the Linux kernel and avoided having the code pulled from the open source operating system.

Microsoft's submission includes 20,000 lines of code that once added to the Linux kernel will provide the hooks for any distribution of Linux to run on Windows Server 2008 and its Hyper-V hypervisor technology. The submission was greeted with astonishment in July when Microsoft made the announcement, which included releasing the code under a GPLv2 license Microsoft had criticized in the past.

Greg Kroah-Hartman, the Linux driver project lead who accepted the code from Microsoft in July, Wednesday called out Microsoft on the linux-kernel and driver-devel mailing lists saying the company was not actively developing its hv drivers. HV refers to Microsoft Hyper-V. He also posted the message to his blog.

"Unfortunately the Microsoft developers seem to have disappeared, and no one is answering my emails. If they do not show back up to claim this driver soon, it will be removed in the 2.6.33 [kernel] release. So sad...," he wrote.

However, in an interview with Network World, Kroah-Hartman said Microsoft got the message.

"They have responded since I posted," he said, and Microsoft is now back at work on the code they pledged to maintain. "This is a normal part of the development process. They are not the only company."

Kroah-Hartman said calling out specific projects on the mailing list is a technique he uses all the time to jump start those that are falling behind.

In all, Kroah-Hartman specifically mentioned 25 driver projects that were not being actively developed and faced being dropped from the main kernel release 2.6.33, which is due in March. He said the driver project was not a "dumping ground for dead code."

However, the nearly 40 projects Kroah-Hartman detailed in his mailing list submission, including the Microsoft drivers, will all be included in the 2.6.32 main kernel release slated for December.

On top of chiding Microsoft for not keeping up with code development, Kroah-Hartman took the company to task for the state of its original code submission.

"Over 200 patches make up the massive cleanup effort needed to just get this code into a semi-sane kernel coding style (someone owes me a big bottle of rum for that work!)," he wrote.

Kroah-Hartman says there are coding style guidelines and that Microsoft's code did not match those. "That's normal and not a big deal. It happens with a lot of companies," he said. But the large number of patches did turn out to be quite a bit of work, he noted.

He said Thursday that Microsoft still has not contributed any patches around the drivers. "They say they are going to contribute, but all they have submitted is changes to update the to-do list."

Kroah-Hartman says he has seen this all before and seemed to chalk it up to the ebbs and flows of the development process.