More changes for 2.6.21

[Posted February 21, 2007 by corbet]

With the release of 2.6.21-rc1, the merge window for this kernel development cycle is now closed. Most of the major 2.6.21 changes were covered here last week, but a number of significant changes did get into the mainline between then and the closing of the window. They are:

The VMI virtualization interface has been merged. VMI is a generic hypervisor interface; it is (now) built on top of paravirt_ops and provides a higher level of functionality.
The clocksource and dynamic tick patches have been merged.
Various improvements to the kernel's support for Sony laptops.
The deprecated ACPI "hotkey" driver has been removed.
Version 1 of the JFFS filesystem has been removed.
The audit subsystem has a "lockdown" mode where further configuration changes cannot be made.
A simple driver allowing Blackberry devices to be charged from a Linux system's USB port has been merged.
A big ARM update has been merged with oprofile support for ARMv6 processors, kexec() support, support for a number of new board and processor variants, and more.
The v9fs (Plan 9) filesystem has seen a number of improvements, mostly in the form of better caching.
The SYSV shared memory code has been reworked for more sane internal file usage and easier integration into the ongoing containers / namespaces work.
A driver for the Silicon Motion SM501 "multimedia companion" chip has been added.

Now the stabilization period begins, with the final 2.6.21 due somewhere approximately around the beginning of May.

More changes for 2.6.21

Posted Feb 22, 2007 6:06 UTC (Thu) by dlang (guest, #313) [Link]

The VMI virtualization interface has been merged. VMI is a generic hypervisor interface; it is (now) built on top of paravirt_ops and provides a higher level of functionality

one way to tell if an abstraction is useful is how many related things can reasonably use it. it looks like parvirt_ops is doing well.

More changes for 2.6.21

Posted Feb 22, 2007 6:09 UTC (Thu) by bradfitz (subscriber, #4378) [Link] (7 responses)

A simple driver allowing Blackberry devices to be charged from a Linux system's USB port has been merged.

That doesn't just ... work?

Or does the Blackberry dynamically request different amounts of current?

You don't see Linux USB power-providing drivers for all those lights and fishtanks and dancing hula girls. What's special about the Blackberry?

Bleckberry charging

Posted Feb 22, 2007 10:48 UTC (Thu) by morhippo (guest, #334) [Link] (2 responses)

Blackberry are sold by millions and are used by influential people. Arguably dancing hula girls look a lot nicer, but are not as essential for most people.

Standard USB current is 100 mV. BBs require 500 mV to charge. Even under Windows, you must install a driver, just to get a BB to charge on the USB port.

This is excellent news. BTW, older kernels can charge the BB by using the bcharge utility (google for it).

Bleckberry charging

Posted Feb 22, 2007 13:49 UTC (Thu) by dion (guest, #2764) [Link]

Well, USB hula girls and personal USB hotplates are rarely true USB devices in that they don't actually communicate with the host and that they often suck much more current than the 100mA without being allowed to.

The Blackberry seems to obey the USB rules.

I think one of the greatest mistakes in USB is that per-port current limiting is not mandatory, if a device used 10% more power than it had been allowed to then it should simply be turned off.

I'm very disappointed that the current crop of hula girls and christmas trees are not actual USB devices with proper HID interfaces to control them:)

Bleckberry charging

Posted Mar 1, 2007 21:09 UTC (Thu) by robert_s (subscriber, #42402) [Link]

"Standard USB current is 100 mV."

What is the world coming to when techies measure current in volts?

More changes for 2.6.21

Posted Feb 22, 2007 19:03 UTC (Thu) by kbob (guest, #1770) [Link] (2 responses)

I'm curious about that too. I have a Motorola RAZR phone. When I plug its USB cable into into a PC running Windows or just running the BIOS, the phone displays "Unauthorized Charger" and the battery doesn't charge. When I plug it into the same PC running Linux, it charges the battery just fine.

Aside from the obvious consideration that Motorola would like me to pay for a Windows driver disk, what's going on here?

Thanks...

More changes for 2.6.21

Posted Feb 22, 2007 20:05 UTC (Thu) by tetromino (guest, #33846) [Link]

Odd. I have a RAZR V3i, and it charges from USB from Linux and Windows equally well. (On the other hand, the transfer rate for photos via USB is an order of magnitude faster in Linux.)

More changes for 2.6.21

Posted Feb 28, 2007 18:53 UTC (Wed) by rjbell4 (guest, #35764) [Link]

With proper drivers, you can charge your RAZR from Windows (or at least, I can charge my RAZR v3m from Windows XP). You can grab the Motorola Phone Tools CD for about $8 from places like PC Microstore, or you can find free drivers by searching the forums at osnn.net.

More changes for 2.6.21

Posted Feb 23, 2007 19:19 UTC (Fri) by gregkh (subscriber, #8) [Link]

Blackberry devices require a "magic command" to be sent to them in order for them to switch into charging mode. This tiny driver sends those commands to the device so it can switch into that mode.