Re: [PATCH 3/3]x86_64: early_printk for early debug port support

[Yinghai Lu]

On 7/18/07, Andi Kleen <ak@xxxxxxx> wrote:
> On Monday 21 May 2007 07:19:18 Yinghai Lu wrote:
> > add early dbgp to early_printk.
> >
> > kernel command line:
> > earlyprintk=dbgp
> > or
> > earlyprintk=dbgp1
>
> Just checking some old patches. Was there ever an update for this one?
> What were the testing results?
>
> -Andi

please check the attachment. the diff to current Linus'd git.

after remove pci quirks for usb handoff, it could get boot log till
ohci try to reset the port with debug device. --- reset will fail.

Maybe Greg could continue debug it.

YH
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9a54148..956d8dc 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -550,11 +550,12 @@ and is between 256 and 4096 characters. It is defined in the file
 	earlyprintk=	[IA-32,X86-64,SH]
 			earlyprintk=vga
 			earlyprintk=serial[,ttySn[,baudrate]]
+			earlyprintk=dbgp
 
 			Append ",keep" to not disable it when the real console
 			takes over.
 
-			Only vga or serial at a time, not both.
+			Only vga or serial or usb debug port at a time.
 
 			Currently only ttyS0 and ttyS1 are supported.
 
diff --git a/arch/x86_64/kernel/early_printk.c b/arch/x86_64/kernel/early_printk.c
index fd9aff3..3621d68 100644
--- a/arch/x86_64/kernel/early_printk.c
+++ b/arch/x86_64/kernel/early_printk.c
@@ -3,10 +3,19 @@
 #include <linux/init.h>
 #include <linux/string.h>
 #include <linux/screen_info.h>
+#include <linux/usb/ch9.h>
+#include <linux/pci_regs.h>
+#include <linux/pci_ids.h>
+#include <linux/errno.h>
 #include <asm/io.h>
 #include <asm/processor.h>
 #include <asm/fcntl.h>
 #include <xen/hvc-console.h>
+#include <asm/pci-direct.h>
+#include <asm/pgtable.h>
+#include <asm/fixmap.h>
+#define EARLY_PRINTK
+#include "../../../drivers/usb/host/ehci.h"
 
 /* Simple VGA output */
 
@@ -156,6 +165,594 @@ static struct console early_serial_console = {
 	.index =	-1,
 };
 
+
+static struct ehci_caps __iomem *ehci_caps;
+static struct ehci_regs __iomem *ehci_regs;
+static struct ehci_dbg_port __iomem *ehci_debug;
+static unsigned dbgp_endpoint_out;
+
+#define USB_DEBUG_DEVNUM 127
+
+#define DBGP_DATA_TOGGLE	0x8800
+
+static inline u32 dbgp_pid_update(u32 x, u32 tok)
+{
+	return ((((x) ^ DBGP_DATA_TOGGLE) & 0xffff00) | ((tok) & 0xff));
+}
+
+static inline u32 dbgp_len_update(u32 x, u32 len)
+{
+	return (((x) & ~0x0f) | ((len) & 0x0f));
+}
+
+/*
+ * USB Packet IDs (PIDs)
+ */
+
+/* token */
+#define USB_PID_OUT		0xe1
+#define USB_PID_IN		0x69
+#define USB_PID_SOF		0xa5
+#define USB_PID_SETUP		0x2d
+/* handshake */
+#define USB_PID_ACK		0xd2
+#define USB_PID_NAK		0x5a
+#define USB_PID_STALL		0x1e
+#define USB_PID_NYET		0x96
+/* data */
+#define USB_PID_DATA0		0xc3
+#define USB_PID_DATA1		0x4b
+#define USB_PID_DATA2		0x87
+#define USB_PID_MDATA		0x0f
+/* Special */
+#define USB_PID_PREAMBLE	0x3c
+#define USB_PID_ERR		0x3c
+#define USB_PID_SPLIT		0x78
+#define USB_PID_PING		0xb4
+#define USB_PID_UNDEF_0		0xf0
+
+#define USB_PID_DATA_TOGGLE	0x88
+#define DBGP_CLAIM (DBGP_OWNER | DBGP_ENABLED | DBGP_INUSE)
+
+#define PCI_CAP_ID_EHCI_DEBUG	0xa
+
+#define HUB_ROOT_RESET_TIME	50	/* times are in msec */
+#define HUB_SHORT_RESET_TIME	10
+#define HUB_LONG_RESET_TIME	200
+#define HUB_RESET_TIMEOUT	500
+
+#define DBGP_MAX_PACKET		8
+
+static int dbgp_wait_until_complete(void)
+{
+	unsigned ctrl;
+	int loop = 0x100000;
+
+	do {
+		ctrl = readl(&ehci_debug->control);
+		/* Stop when the transaction is finished */
+		if (ctrl & DBGP_DONE)
+			break;
+	} while (--loop > 0);
+
+	if (!loop)
+		return -1;
+
+	/* Now that we have observed the completed transaction,
+	 * clear the done bit.
+	 */
+	writel(ctrl | DBGP_DONE, &ehci_debug->control);
+	return (ctrl & DBGP_ERROR) ? -DBGP_ERRCODE(ctrl) : DBGP_LEN(ctrl);
+}
+
+static void dbgp_mdelay(int ms)
+{
+	int i;
+	while (ms--) {
+		for (i = 0; i < 1000; i++)
+			outb(0x1, 0x80);
+	}
+}
+
+static void dbgp_breath(void)
+{
+	/* Sleep to give the debug port a chance to breathe */
+}
+
+static int dbgp_wait_until_done(unsigned ctrl)
+{
+	unsigned pids, lpid;
+	int ret;
+	int loop = 3;
+
+retry:
+	writel(ctrl | DBGP_GO, &ehci_debug->control);
+	ret = dbgp_wait_until_complete();
+	pids = readl(&ehci_debug->pids);
+	lpid = DBGP_PID_GET(pids);
+
+	if (ret < 0)
+		return ret;
+
+	/* If the port is getting full or it has dropped data
+	 * start pacing ourselves, not necessary but it's friendly.
+	 */
+	if ((lpid == USB_PID_NAK) || (lpid == USB_PID_NYET))
+		dbgp_breath();
+
+	/* If I get a NACK reissue the transmission */
+	if (lpid == USB_PID_NAK) {
+		if(--loop > 0)
+			goto retry;
+	}
+
+	return ret;
+}
+
+static void dbgp_set_data(const void *buf, int size)
+{
+	const unsigned char *bytes = buf;
+	unsigned lo, hi;
+	int i;
+
+	lo = hi = 0;
+	for (i = 0; i < 4 && i < size; i++)
+		lo |= bytes[i] << (8*i);
+	for (; i < 8 && i < size; i++)
+		hi |= bytes[i] << (8*(i - 4));
+	writel(lo, &ehci_debug->data03);
+	writel(hi, &ehci_debug->data47);
+}
+
+static void dbgp_get_data(void *buf, int size)
+{
+	unsigned char *bytes = buf;
+	unsigned lo, hi;
+	int i;
+	lo = readl(&ehci_debug->data03);
+	hi = readl(&ehci_debug->data47);
+	for (i = 0; i < 4 && i < size; i++)
+		bytes[i] = (lo >> (8*i)) & 0xff;
+	for (; i < 8 && i < size; i++)
+		bytes[i] = (hi >> (8*(i - 4))) & 0xff;
+}
+
+static int dbgp_bulk_write(unsigned devnum, unsigned endpoint,
+			 const char *bytes, int size)
+{
+	unsigned pids, addr, ctrl;
+	int ret;
+	if (size > DBGP_MAX_PACKET)
+		return -1;
+
+	addr = DBGP_EPADDR(devnum, endpoint);
+
+	pids = readl(&ehci_debug->pids);
+	pids = dbgp_pid_update(pids, USB_PID_OUT);
+
+	ctrl = readl(&ehci_debug->control);
+	ctrl = dbgp_len_update(ctrl, size);
+	ctrl |= DBGP_OUT;
+	ctrl |= DBGP_GO;
+
+	dbgp_set_data(bytes, size);
+	writel(addr, &ehci_debug->address);
+	writel(pids, &ehci_debug->pids);
+
+	ret = dbgp_wait_until_done(ctrl);
+	if (ret < 0)
+		return ret;
+
+	return ret;
+}
+
+static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data, int size)
+{
+	unsigned pids, addr, ctrl;
+	int ret;
+
+	if (size > DBGP_MAX_PACKET)
+		return -1;
+
+	addr = DBGP_EPADDR(devnum, endpoint);
+
+	pids = readl(&ehci_debug->pids);
+	pids = dbgp_pid_update(pids, USB_PID_IN);
+
+	ctrl = readl(&ehci_debug->control);
+	ctrl = dbgp_len_update(ctrl, size);
+	ctrl &= ~DBGP_OUT;
+	ctrl |= DBGP_GO;
+
+	writel(addr, &ehci_debug->address);
+	writel(pids, &ehci_debug->pids);
+	ret = dbgp_wait_until_done(ctrl);
+	if (ret < 0)
+		return ret;
+	if (size > ret)
+		size = ret;
+	dbgp_get_data(data, size);
+	return ret;
+}
+
+static int dbgp_control_msg(unsigned devnum, int requesttype, int request,
+	int value, int index, void *data, int size)
+{
+	unsigned pids, addr, ctrl;
+	struct usb_ctrlrequest req;
+	int read;
+	int ret;
+
+	read = (requesttype & USB_DIR_IN) != 0;
+	if (size > (read ? DBGP_MAX_PACKET:0))
+		return -1;
+
+	/* Compute the control message */
+	req.bRequestType = requesttype;
+	req.bRequest = request;
+	req.wValue = value;
+	req.wIndex = index;
+	req.wLength = size;
+
+	pids = DBGP_PID_SET(USB_PID_DATA0, USB_PID_SETUP);
+	addr = DBGP_EPADDR(devnum, 0);
+
+	ctrl = readl(&ehci_debug->control);
+	ctrl = dbgp_len_update(ctrl, sizeof(req));
+	ctrl |= DBGP_OUT;
+	ctrl |= DBGP_GO;
+
+	/* Send the setup message */
+	dbgp_set_data(&req, sizeof(req));
+	writel(addr, &ehci_debug->address);
+	writel(pids, &ehci_debug->pids);
+	ret = dbgp_wait_until_done(ctrl);
+	if (ret < 0)
+		return ret;
+
+	/* Read the result */
+	ret = dbgp_bulk_read(devnum, 0, data, size);
+	return ret;
+}
+
+
+/* Find a PCI capability */
+static __u32 __init find_cap(int num, int slot, int func, int cap)
+{
+	u8 pos;
+	int bytes;
+	if (!(read_pci_config_16(num,slot,func,PCI_STATUS) & PCI_STATUS_CAP_LIST))
+		return 0;
+	pos = read_pci_config_byte(num,slot,func,PCI_CAPABILITY_LIST);
+	for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
+		u8 id;
+		pos &= ~3;
+		id = read_pci_config_byte(num,slot,func,pos+PCI_CAP_LIST_ID);
+		if (id == 0xff)
+			break;
+		if (id == cap)
+			return pos;
+		pos = read_pci_config_byte(num,slot,func,pos+PCI_CAP_LIST_NEXT);
+	}
+	return 0;
+}
+
+static __u32 __init find_dbgp(int ehci_num, unsigned *rbus, unsigned *rslot, unsigned *rfunc)
+{
+	unsigned bus, slot, func;
+
+	for (bus = 0; bus < 256; bus++) {
+		for (slot = 0; slot < 32; slot++) {
+			for (func = 0; func < 8; func++) {
+				u32 class;
+				unsigned cap;
+				class = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
+				if ((class >> 8) != PCI_CLASS_SERIAL_USB_EHCI)
+					continue;
+				cap = find_cap(bus, slot, func, PCI_CAP_ID_EHCI_DEBUG);
+				if (!cap)
+					continue;
+				if (ehci_num-- != 0)
+					continue;
+				*rbus = bus;
+				*rslot = slot;
+				*rfunc = func;
+				return cap;
+			}
+		}
+	}
+	return 0;
+}
+
+static int ehci_reset_port(int port)
+{
+	unsigned portsc;
+	unsigned delay_time, delay;
+	int loop;
+
+	/* Reset the usb debug port */
+	portsc = readl(&ehci_regs->port_status[port - 1]);
+	portsc &= ~PORT_PE;
+	portsc |= PORT_RESET;
+	writel(portsc, &ehci_regs->port_status[port - 1]);
+
+	delay = HUB_ROOT_RESET_TIME;
+	for (delay_time = 0; delay_time < HUB_RESET_TIMEOUT;
+	     delay_time += delay) {
+		dbgp_mdelay(delay);
+
+		portsc = readl(&ehci_regs->port_status[port - 1]);
+		if (portsc & PORT_RESET) {
+			/* force reset to complete */
+			loop = 2;
+			writel(portsc & ~(PORT_RWC_BITS | PORT_RESET),
+				&ehci_regs->port_status[port - 1]);
+			do {
+				portsc = readl(&ehci_regs->port_status[port - 1]);
+			} while ((portsc & PORT_RESET) && (--loop > 0));
+		}
+
+		/* Device went away? */
+		if (!(portsc & PORT_CONNECT))
+			return -ENOTCONN;
+
+		/* bomb out completely if something weird happend */
+		if ((portsc & PORT_CSC))
+			return -EINVAL;
+
+		/* If we've finished resetting, then break out of the loop */
+		if (!(portsc & PORT_RESET) && (portsc & PORT_PE))
+			return 0;
+	}
+	return -EBUSY;
+}
+
+static int ehci_wait_for_port(int port)
+{
+	unsigned status;
+	int ret, reps;
+
+	for (reps = 0; reps < 3; reps++) {
+		dbgp_mdelay(100);
+		status = readl(&ehci_regs->status);
+		if (status & STS_PCD) {
+			ret = ehci_reset_port(port);
+			if (ret == 0)
+				return 0;
+		}
+	}
+	return -ENOTCONN;
+}
+
+
+#define DBGP_DEBUG 0
+#if DBGP_DEBUG
+void early_printk(const char *fmt, ...);
+# define dbgp_printk early_printk
+#else
+static inline void dbgp_printk(const char *fmt, ...) { }
+#endif
+
+static int ehci_setup(void)
+{
+	unsigned cmd, ctrl, status, portsc, hcs_params, debug_port, n_ports;
+	int ret;
+	int loop;
+
+	hcs_params = readl(&ehci_caps->hcs_params);
+	debug_port = HCS_DEBUG_PORT(hcs_params);
+	n_ports    = HCS_N_PORTS(hcs_params);
+
+	dbgp_printk("debug_port: %d\n", debug_port);
+	dbgp_printk("n_ports:    %d\n", n_ports);
+
+	loop = 10;
+	/* Reset the EHCI controller */
+	cmd = readl(&ehci_regs->command);
+	cmd |= CMD_RESET;
+	writel(cmd, &ehci_regs->command);
+	do {
+		cmd = readl(&ehci_regs->command);
+	} while ((cmd & CMD_RESET) && (--loop > 0));
+
+	/* Claim ownership, but do not enable yet */
+	ctrl = readl(&ehci_debug->control);
+	ctrl |= DBGP_OWNER;
+	ctrl &= ~(DBGP_ENABLED | DBGP_INUSE);
+	writel(ctrl, &ehci_debug->control);
+
+	/* Start the ehci running */
+	cmd = readl(&ehci_regs->command);
+	cmd &= ~(CMD_LRESET | CMD_IAAD | CMD_PSE | CMD_ASE | CMD_RESET);
+	cmd |= CMD_RUN;
+	writel(cmd, &ehci_regs->command);
+
+	/* Ensure everything is routed to the EHCI */
+	writel(FLAG_CF, &ehci_regs->configured_flag);
+
+	/* Wait until the controller is no longer halted */
+	loop = 10;
+	do {
+		status = readl(&ehci_regs->status);
+	} while ((status & STS_HALT) && (--loop > 0));
+
+	/* Wait for a device to show up in the debug port */
+	ret = ehci_wait_for_port(debug_port);
+	if (ret < 0) {
+		dbgp_printk("No device found in debug port\n");
+		return -1;
+	}
+
+	/* Enable the debug port */
+	ctrl = readl(&ehci_debug->control);
+	ctrl |= DBGP_CLAIM;
+	writel(ctrl, &ehci_debug->control);
+	ctrl = readl(&ehci_debug->control);
+	if ((ctrl & DBGP_CLAIM) != DBGP_CLAIM) {
+		dbgp_printk("No device in debug port\n");
+		writel(ctrl & ~DBGP_CLAIM, &ehci_debug->control);
+		return -1;
+
+	}
+
+	/* Completely transfer the debug device to the debug controller */
+	portsc = readl(&ehci_regs->port_status[debug_port - 1]);
+	portsc &= ~PORT_PE;
+	writel(portsc, &ehci_regs->port_status[debug_port - 1]);
+
+	return 0;
+}
+
+static int __init early_dbgp_init(char *s)
+{
+	struct usb_debug_descriptor dbgp_desc;
+	void __iomem *ehci_bar;
+	unsigned ctrl, devnum;
+	unsigned bus, slot, func, cap;
+	unsigned debug_port, bar, offset;
+	unsigned bar_val;
+	char *e;
+	int ret;
+	unsigned dbgp_num;
+
+	if (!early_pci_allowed())
+		return -1;
+
+	dbgp_num = 0;
+	if (*s) {
+		dbgp_num = simple_strtoul(s, &e, 10);
+	}
+	dbgp_printk("dbgp_num: %d\n", dbgp_num);
+	cap = find_dbgp(dbgp_num, &bus, &slot, &func);
+	if (!cap)
+		return -1;
+
+	dbgp_printk("Found EHCI debug port\n");
+
+	debug_port = read_pci_config(bus, slot, func, cap);
+	bar = (debug_port >> 29) & 0x7;
+	bar = (bar * 4) + 0xc;
+	offset = (debug_port >> 16) & 0xfff;
+	dbgp_printk("bar: %02x offset: %03x\n", bar, offset);
+	if (bar != PCI_BASE_ADDRESS_0) {
+		dbgp_printk("only debug ports on bar 1 handled.\n");
+		return -1;
+	}
+
+	bar_val = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
+	dbgp_printk("bar_val: %02x offset: %03x\n", bar_val, offset);
+	if (bar_val & ~PCI_BASE_ADDRESS_MEM_MASK) {
+		dbgp_printk("only simple 32bit mmio bars supported\n");
+		return -1;
+	}
+
+
+	/* FIXME I don't have the bar size so just guess PAGE_SIZE is more
+	 * than enough.  1K is the biggest I have seen.
+	 */
+	dbgp_printk("dbgp pre-set_fixmap_nocache\n");
+	set_fixmap_nocache(FIX_DBGP_BASE, bar_val & PAGE_MASK);
+	dbgp_printk("dbgp post-set_fixmap_nocache\n");
+	ehci_bar = (void __iomem *)__fix_to_virt(FIX_DBGP_BASE);
+	ehci_bar += bar_val & ~PAGE_MASK;
+	dbgp_printk("ehci_bar: %p\n", ehci_bar);
+
+	ehci_caps  = ehci_bar;
+	ehci_regs  = ehci_bar + HC_LENGTH(readl(&ehci_caps->hc_capbase));
+	ehci_debug = ehci_bar + offset;
+
+	ret = ehci_setup();
+	if (ret < 0) {
+		dbgp_printk("ehci_setup failed\n");
+		ehci_debug = 0;
+		return -1;
+	}
+	dbgp_mdelay(100);
+
+	/* Find the debug device and make it device number 127 */
+	for (devnum = 0; devnum <= 127; devnum++) {
+		ret = dbgp_control_msg(devnum,
+			USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
+			USB_REQ_GET_DESCRIPTOR, (USB_DT_DEBUG << 8), 0,
+			&dbgp_desc, sizeof(dbgp_desc));
+		if (ret > 0)
+			break;
+	}
+	if (devnum > 127) {
+		dbgp_printk("Could not find attached debug device\n");
+		goto err;
+	}
+	if (ret < 0) {
+		dbgp_printk("Attached device is not a debug device\n");
+		goto err;
+	}
+	dbgp_endpoint_out = dbgp_desc.bDebugOutEndpoint;
+
+	/* Move the device to 127 if it isn't already there */
+	if (devnum != USB_DEBUG_DEVNUM) {
+		ret = dbgp_control_msg(devnum,
+			USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
+			USB_REQ_SET_ADDRESS, USB_DEBUG_DEVNUM, 0, NULL, 0);
+		if (ret < 0) {
+			dbgp_printk("Could not move attached device to %d\n",
+				USB_DEBUG_DEVNUM);
+			goto err;
+		}
+		devnum = USB_DEBUG_DEVNUM;
+	}
+
+	/* Enable the debug interface */
+	ret = dbgp_control_msg(USB_DEBUG_DEVNUM,
+		USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE,
+		USB_REQ_SET_FEATURE, USB_DEVICE_DEBUG_MODE, 0, NULL, 0);
+	if (ret < 0) {
+		dbgp_printk(" Could not enable the debug device\n");
+		goto err;
+	}
+
+	/* Perform a small write to get the even/odd data state in sync
+	 */
+	ret = dbgp_bulk_write(USB_DEBUG_DEVNUM, dbgp_endpoint_out, " ",1);
+	if (ret < 0) {
+		dbgp_printk("dbgp_bulk_write failed: %d\n", ret);
+		goto err;
+	}
+
+
+	return 0;
+err:
+	/* Things didn't work so remove my claim */
+	ctrl = readl(&ehci_debug->control);
+	ctrl &= ~(DBGP_CLAIM | DBGP_OUT);
+	writel(ctrl, &ehci_debug->control);
+	ehci_debug = 0;
+
+	return -1;
+}
+
+static void early_dbgp_write(struct console *con, const char *str, unsigned n)
+{
+	int chunk, ret;
+	if (!ehci_debug)
+		return;
+	while (n > 0) {
+		chunk = n;
+		if (chunk > DBGP_MAX_PACKET)
+			chunk = DBGP_MAX_PACKET;
+		ret = dbgp_bulk_write(USB_DEBUG_DEVNUM,
+			dbgp_endpoint_out, str, chunk);
+		str += chunk;
+		n -= chunk;
+	}
+}
+
+static struct console early_dbgp_console = {
+	.name =		"earlydbg",
+	.write =	early_dbgp_write,
+	.flags =	CON_PRINTBUFFER,
+	.index =	-1,
+};
+
 /* Console interface to a host file on AMD's SimNow! */
 
 static int simnow_fd;
@@ -213,10 +810,11 @@ void early_printk(const char *fmt, ...)
 	va_end(ap);
 }
 
-static int __initdata keep_early;
 
 static int __init setup_early_printk(char *buf)
 {
+	int keep_early;
+
 	if (!buf)
 		return 0;
 
@@ -224,8 +822,7 @@ static int __init setup_early_printk(char *buf)
 		return 0;
 	early_console_initialized = 1;
 
-	if (strstr(buf, "keep"))
-		keep_early = 1;
+	keep_early = (strstr(buf, "keep") != NULL);
 
 	if (!strncmp(buf, "serial", 6)) {
 		early_serial_init(buf + 6);
@@ -239,10 +836,14 @@ static int __init setup_early_printk(char *buf)
 		max_ypos = SCREEN_INFO.orig_video_lines;
 		current_ypos = SCREEN_INFO.orig_y;
 		early_console = &early_vga_console;
- 	} else if (!strncmp(buf, "simnow", 6)) {
- 		simnow_init(buf + 6);
- 		early_console = &simnow_console;
- 		keep_early = 1;
+	} else if (!strncmp(buf, "simnow", 6)) {
+		simnow_init(buf + 6);
+		early_console = &simnow_console;
+		keep_early = 1;
+	} else if (!strncmp(buf, "dbgp", 4)) {
+		if (early_dbgp_init(buf+4) < 0)
+			return 0;
+		early_console = &early_dbgp_console;
 #ifdef CONFIG_HVC_XEN
 	} else if (!strncmp(buf, "xen", 3)) {
 		early_console = &xenboot_console;
@@ -256,4 +857,17 @@ static int __init setup_early_printk(char *buf)
 	register_console(early_console);
 	return 0;
 }
+
+void __init enable_debug_console(char *buf)
+{
+#if DBGP_DEBUG
+	if(early_console_initialized && early_console) {
+		unregister_console(early_console);
+		early_console_initialized = 0;
+	}
+
+	setup_early_printk(buf);
+#endif
+}
+
 early_param("earlyprintk", setup_early_printk);
diff --git a/arch/x86_64/kernel/head64.c b/arch/x86_64/kernel/head64.c
index 6c34bdd..b972f7c 100644
--- a/arch/x86_64/kernel/head64.c
+++ b/arch/x86_64/kernel/head64.c
@@ -58,6 +58,8 @@ static void __init copy_bootdata(char *real_mode_data)
 	memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 }
 
+extern void __init enable_debug_console(char *buf);
+
 void __init x86_64_start_kernel(char * real_mode_data)
 {
 	int i;
@@ -74,10 +76,14 @@ void __init x86_64_start_kernel(char * real_mode_data)
 
 	early_printk("Kernel alive\n");
 
- 	for (i = 0; i < NR_CPUS; i++)
- 		cpu_pda(i) = &boot_cpu_pda[i];
+	for (i = 0; i < NR_CPUS; i++)
+		cpu_pda(i) = &boot_cpu_pda[i];
 
 	pda_init(0);
+
+	enable_debug_console("ttyS0,115200");
+	enable_debug_console("dbgp,keep");
+
 	copy_bootdata(__va(real_mode_data));
 #ifdef CONFIG_SMP
 	cpu_set(0, cpu_online_map);
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index c4e15ed..d772a63 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -213,8 +213,13 @@ static void tdi_reset (struct ehci_hcd *ehci)
 static int ehci_reset (struct ehci_hcd *ehci)
 {
 	int	retval;
-	u32	command = ehci_readl(ehci, &ehci->regs->command);
+	u32	command;
 
+	/* don't reset, if debug port is used */
+	if (ehci->debug)
+		return 0;
+
+	command = ehci_readl(ehci, &ehci->regs->command);
 	command |= CMD_RESET;
 	dbg_cmd (ehci, "reset", command);
 	ehci_writel(ehci, command, &ehci->regs->command);
@@ -396,11 +401,17 @@ static void ehci_port_power (struct ehci_hcd *ehci, int is_on)
 		return;
 
 	ehci_dbg (ehci, "...power%s ports...\n", is_on ? "up" : "down");
-	for (port = HCS_N_PORTS (ehci->hcs_params); port > 0; )
+	for (port = HCS_N_PORTS (ehci->hcs_params); port > 0; ) {
+		/* do not touch debug port if it is used */
+		if (ehci->debug && port == HCS_DEBUG_PORT(ehci->hcs_params))
+			continue;
+
 		(void) ehci_hub_control(ehci_to_hcd(ehci),
 				is_on ? SetPortFeature : ClearPortFeature,
 				USB_PORT_FEAT_POWER,
 				port--, NULL, 0);
+	}
+
 	/* Flush those writes */
 	ehci_readl(ehci, &ehci->regs->command);
 	msleep(20);
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 2c68a04..9842a05 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -62,6 +62,7 @@ struct ehci_stats {
 
 #define	EHCI_MAX_ROOT_PORTS	15		/* see HCS_N_PORTS */
 
+#ifndef EARLY_PRINTK
 struct ehci_hcd {			/* one per controller */
 	/* glue to PCI and HCD framework */
 	struct ehci_caps __iomem *caps;
@@ -192,6 +193,7 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action)
 		mod_timer (&ehci->watchdog, t);
 	}
 }
+#endif /* EARLY_PRINTK */
 
 /*-------------------------------------------------------------------------*/
 
@@ -337,6 +339,8 @@ struct ehci_dbg_port {
 
 #define	QTD_NEXT(ehci, dma)	cpu_to_hc32(ehci, (u32)dma)
 
+#ifndef EARLY_PRINTK
+
 /*
  * EHCI Specification 0.95 Section 3.5
  * QTD: describe data transfer components (buffer, direction, ...)
@@ -377,7 +381,7 @@ struct ehci_qtd {
 	struct urb		*urb;			/* qtd's urb */
 	size_t			length;			/* length of buffer */
 } __attribute__ ((aligned (32)));
-
+#endif
 /* mask NakCnt+T in qh->hw_alt_next */
 #define QTD_MASK(ehci)	cpu_to_hc32 (ehci, ~0x1f)
 
@@ -434,6 +438,7 @@ union ehci_shadow {
  * These appear in both the async and (for interrupt) periodic schedules.
  */
 
+#ifndef EARLY_PRINTK
 struct ehci_qh {
 	/* first part defined by EHCI spec */
 	__hc32			hw_next;	/* see EHCI 3.6.1 */
@@ -497,6 +502,7 @@ struct ehci_qh {
 	__le32			was_active;	/* active bit before "i" set */
 #endif
 } __attribute__ ((aligned (32)));
+#endif /* EARLY_PRITNK */
 
 /*-------------------------------------------------------------------------*/
 
@@ -510,6 +516,7 @@ struct ehci_iso_packet {
 	u32			buf1;
 };
 
+#ifndef EARLY_PRINTK
 /* temporary schedule data for packets from iso urbs (both speeds)
  * each packet is one logical usb transaction to the device (not TT),
  * beginning at stream->next_uframe
@@ -645,6 +652,7 @@ struct ehci_sitd {
 	unsigned		frame;
 	unsigned		index;
 } __attribute__ ((aligned (32)));
+#endif
 
 /*-------------------------------------------------------------------------*/
 
@@ -666,6 +674,8 @@ struct ehci_fstn {
 	union ehci_shadow	fstn_next;	/* ptr to periodic q entry */
 } __attribute__ ((aligned (32)));
 
+#ifndef EARLY_PRINTK
+
 /*-------------------------------------------------------------------------*/
 
 #ifdef CONFIG_USB_EHCI_ROOT_HUB_TT
@@ -832,4 +842,6 @@ static inline u32 hc32_to_cpup (const struct ehci_hcd *ehci, const __hc32 *x)
 
 /*-------------------------------------------------------------------------*/
 
+#endif /* EARLY_PRINTK */
+
 #endif /* __LINUX_EHCI_HCD_H */
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index c225159..3b379ff 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -358,4 +358,4 @@ static void __devinit quirk_usb_early_handoff(struct pci_dev *pdev)
 	else if (pdev->class == PCI_CLASS_SERIAL_USB_EHCI)
 		quirk_usb_disable_ehci(pdev);
 }
-DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, quirk_usb_early_handoff);
+//DECLARE_PCI_FIXUP_FINAL(PCI_ANY_ID, PCI_ANY_ID, quirk_usb_early_handoff);