summaryrefslogtreecommitdiffstats
path: root/drivers/usb/Makefile
diff options
context:
space:
mode:
authorLu Baolu <baolu.lu@linux.intel.com>2017-03-21 16:01:30 +0800
committerIngo Molnar <mingo@kernel.org>2017-03-21 12:30:05 +0100
commitaeb9dd1de98c1a5f2007ea5d2a154c1244caf8a0 (patch)
tree8882865e704b39e2408f072794a653f1f58966ec /drivers/usb/Makefile
parentdd759d93f4dd4fd2f345a78ad1223bb3edf3ee7b (diff)
downloadlinux-aeb9dd1de98c1a5f2007ea5d2a154c1244caf8a0.tar.bz2
usb/early: Add driver for xhci debug capability
XHCI debug capability (DbC) is an optional but standalone functionality provided by an xHCI host controller. Software learns this capability by walking through the extended capability list of the host. XHCI specification describes DbC in section 7.6. This patch introduces the code to probe and initialize the debug capability hardware during early boot. With hardware initialized, the debug target (system on which this code is running) will present a debug device through the 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 the xHCI host. There isn't any precondition from the xHCI host side for the DbC to work. One use for this feature is kernel debugging, for example when your machine crashes very early before the regular console code is initialized. Other uses include simpler, lockless logging instead of a full-blown printk console driver and klogd. Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathias Nyman <mathias.nyman@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-usb@vger.kernel.org Link: http://lkml.kernel.org/r/1490083293-3792-3-git-send-email-baolu.lu@linux.intel.com [ Small fix to the Kconfig help text. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/usb/Makefile')
-rw-r--r--drivers/usb/Makefile2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/Makefile b/drivers/usb/Makefile
index 7791af6c102c..53d1356bbd06 100644
--- a/drivers/usb/Makefile
+++ b/drivers/usb/Makefile
@@ -49,7 +49,7 @@ obj-$(CONFIG_USB_MICROTEK) += image/
obj-$(CONFIG_USB_SERIAL) += serial/
obj-$(CONFIG_USB) += misc/
-obj-$(CONFIG_EARLY_PRINTK_DBGP) += early/
+obj-$(CONFIG_EARLY_PRINTK_USB) += early/
obj-$(CONFIG_USB_ATM) += atm/
obj-$(CONFIG_USB_SPEEDTOUCH) += atm/