Hi, On 10/25/2016 02:36 PM, Greg Kroah-Hartman wrote: > On Tue, Oct 25, 2016 at 12:32:41PM +0800, Lu Baolu wrote: >> xHCI debug capability (DbC) is an optional but standalone >> functionality provided by an xHCI host controller. With DbC >> hardware initialized, the system will present a debug device >> through the USB3 debug port (normally the first USB3 port). >> The debug device is fully compliant with the USB framework >> and provides the equivalent of a very high performance (USB3) >> full-duplex serial link between the debug host and target. >> The DbC functionality is independent of xHCI host. There >> isn't any precondition from xHCI host side for DbC to work. >> >> This patch set adds support for early printk functionality >> through a USB3 debug port by 1) initializing and enabling >> the DbC hardware during early boot; 2) registering a boot >> console to the system so that early printk messages can go >> through the USB3 debug port. It also includes some lines >> of changes in usb_debug driver so that it can be bound when >> a USB3 debug device is enumerated. >> >> This code is designed to be used only for kernel debugging >> when machine crashes very early before the console code is >> initialized. It makes the life of kernel debugging easier >> when people work with a modern machine without any legacy >> serial ports. >> >> --- >> Change log: >> v2->v3: >> - Removed spinlock usage. >> - Removed work queue usage. >> - Refined the user guide document. > How is this a "RESEND" if this is the first time we have seen v3? > > confused, Sorry, I shouldn't add this. I will remove it if it needs a refreshed version. Best regards, Lu Baolu > > greg k-h > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
