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Commit 4968f951 authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: EHCI: remove unused Link Power Management code 



This patch (as1622) removes the USB-2.1 Link Power Management code
from the ehci-hcd driver.  This code was never integrated with
usbcore, it is full of bugs, and it was not getting used by anybody.

However, the debugging code for dumping the LPM-related fields in the
EHCI registers is left in place.  In theory it might be useful to see
these values, even though we don't use them.

This essentially amounts to a partial revert of commit
aa4d8342 (USB: EHCI: EHCI 1.1
addendum: preparation) and an almost full revert of commit
48f24970 (USB: EHCI: EHCI 1.1
addendum: Basic LPM feature support) plus its follow-ons.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 571e4121

drivers/usb/host/ehci-dbg.c

+0 −97
Original line number Diff line number Diff line
@@ -337,11 +337,6 @@ static int debug_async_open(struct inode *, struct file *); 
static int debug_periodic_open(struct inode *, struct file *);

static int debug_registers_open(struct inode *, struct file *);

static int debug_async_open(struct inode *, struct file *);

static ssize_t debug_lpm_read(struct file *file, char __user *user_buf,

				   size_t count, loff_t *ppos);

static ssize_t debug_lpm_write(struct file *file, const char __user *buffer,

			      size_t count, loff_t *ppos);

static int debug_lpm_close(struct inode *inode, struct file *file);



static ssize_t debug_output(struct file*, char __user*, size_t, loff_t*);

static int debug_close(struct inode *, struct file *);
@@ -367,14 +362,6 @@ static const struct file_operations debug_registers_fops = { 
	.release	= debug_close,

	.llseek		= default_llseek,

};

static const struct file_operations debug_lpm_fops = {

	.owner		= THIS_MODULE,

	.open		= simple_open,

	.read		= debug_lpm_read,

	.write		= debug_lpm_write,

	.release	= debug_lpm_close,

	.llseek		= noop_llseek,

};



static struct dentry *ehci_debug_root;
@@ -956,86 +943,6 @@ static int debug_registers_open(struct inode *inode, struct file *file) 
	return file->private_data ? 0 : -ENOMEM;

}



static int debug_lpm_close(struct inode *inode, struct file *file)

{

	return 0;

}



static ssize_t debug_lpm_read(struct file *file, char __user *user_buf,

				   size_t count, loff_t *ppos)

{

	/* TODO: show lpm stats */

	return 0;

}



static ssize_t debug_lpm_write(struct file *file, const char __user *user_buf,

			      size_t count, loff_t *ppos)

{

	struct usb_hcd		*hcd;

	struct ehci_hcd		*ehci;

	char buf[50];

	size_t len;

	u32 temp;

	unsigned long port;

	u32 __iomem	*portsc ;

	u32 params;



	hcd = bus_to_hcd(file->private_data);

	ehci = hcd_to_ehci(hcd);



	len = min(count, sizeof(buf) - 1);

	if (copy_from_user(buf, user_buf, len))

		return -EFAULT;

	buf[len] = '\0';

	if (len > 0 && buf[len - 1] == '\n')

		buf[len - 1] = '\0';



	if (strncmp(buf, "enable", 5) == 0) {

		if (strict_strtoul(buf + 7, 10, &port))

			return -EINVAL;

		params = ehci_readl(ehci, &ehci->caps->hcs_params);

		if (port > HCS_N_PORTS(params)) {

			ehci_dbg(ehci, "ERR: LPM on bad port %lu\n", port);

			return -ENODEV;

		}

		portsc = &ehci->regs->port_status[port-1];

		temp = ehci_readl(ehci, portsc);

		if (!(temp & PORT_DEV_ADDR)) {

			ehci_dbg(ehci, "LPM: no device attached\n");

			return -ENODEV;

		}

		temp |= PORT_LPM;

		ehci_writel(ehci, temp, portsc);

		printk(KERN_INFO "force enable LPM for port %lu\n", port);

	} else if (strncmp(buf, "hird=", 5) == 0) {

		unsigned long hird;

		if (strict_strtoul(buf + 5, 16, &hird))

			return -EINVAL;

		printk(KERN_INFO "setting hird %s %lu\n", buf + 6, hird);

		ehci->command = (ehci->command & ~CMD_HIRD) | (hird << 24);

		ehci_writel(ehci, ehci->command, &ehci->regs->command);

	} else if (strncmp(buf, "disable", 7) == 0) {

		if (strict_strtoul(buf + 8, 10, &port))

			return -EINVAL;

		params = ehci_readl(ehci, &ehci->caps->hcs_params);

		if (port > HCS_N_PORTS(params)) {

			ehci_dbg(ehci, "ERR: LPM off bad port %lu\n", port);

			return -ENODEV;

		}

		portsc = &ehci->regs->port_status[port-1];

		temp = ehci_readl(ehci, portsc);

		if (!(temp & PORT_DEV_ADDR)) {

			ehci_dbg(ehci, "ERR: no device attached\n");

			return -ENODEV;

		}

		temp &= ~PORT_LPM;

		ehci_writel(ehci, temp, portsc);

		printk(KERN_INFO "disabled LPM for port %lu\n", port);

	} else

		return -EOPNOTSUPP;

	return count;

}



static inline void create_debug_files (struct ehci_hcd *ehci)

{

	struct usb_bus *bus = &ehci_to_hcd(ehci)->self;
@@ -1056,10 +963,6 @@ static inline void create_debug_files (struct ehci_hcd *ehci) 
						    &debug_registers_fops))

		goto file_error;



	if (!debugfs_create_file("lpm", S_IRUGO|S_IWUSR, ehci->debug_dir, bus,

						    &debug_lpm_fops))

		goto file_error;



	return;



file_error:

drivers/usb/host/ehci-hcd.c

+0 −18
Original line number Diff line number Diff line
@@ -39,7 +39,6 @@ 
#include <linux/dma-mapping.h>

#include <linux/debugfs.h>

#include <linux/slab.h>

#include <linux/uaccess.h>



#include <asm/byteorder.h>

#include <asm/io.h>
@@ -108,11 +107,6 @@ static bool ignore_oc = 0; 
module_param (ignore_oc, bool, S_IRUGO);

MODULE_PARM_DESC (ignore_oc, "ignore bogus hardware overcurrent indications");



/* for link power management(LPM) feature */

static unsigned int hird;

module_param(hird, int, S_IRUGO);

MODULE_PARM_DESC(hird, "host initiated resume duration, +1 for each 75us");



#define	INTR_MASK (STS_IAA | STS_FATAL | STS_PCD | STS_ERR | STS_INT)



/*-------------------------------------------------------------------------*/
@@ -318,7 +312,6 @@ static void end_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh); 


#include "ehci-timer.c"

#include "ehci-hub.c"

#include "ehci-lpm.c"

#include "ehci-mem.c"

#include "ehci-q.c"

#include "ehci-sched.c"
@@ -580,17 +573,6 @@ static int ehci_init(struct usb_hcd *hcd) 
		temp &= ~(3 << 2);

		temp |= (EHCI_TUNE_FLS << 2);

	}

	if (HCC_LPM(hcc_params)) {

		/* support link power management EHCI 1.1 addendum */

		ehci_dbg(ehci, "support lpm\n");

		ehci->has_lpm = 1;

		if (hird > 0xf) {

			ehci_dbg(ehci, "hird %d invalid, use default 0",

			hird);

			hird = 0;

		}

		temp |= hird << 24;

	}

	ehci->command = temp;



	/* Accept arbitrarily long scatter-gather lists */

drivers/usb/host/ehci-hub.c

+0 −5
Original line number Diff line number Diff line
@@ -777,11 +777,6 @@ static int ehci_hub_control ( 
						status_reg);

			break;

		case USB_PORT_FEAT_C_CONNECTION:

			if (ehci->has_lpm) {

				/* clear PORTSC bits on disconnect */

				temp &= ~PORT_LPM;

				temp &= ~PORT_DEV_ADDR;

			}

			ehci_writel(ehci, temp | PORT_CSC, status_reg);

			break;

		case USB_PORT_FEAT_C_OVER_CURRENT:

drivers/usb/host/ehci-lpm.c

deleted100644 → 0
+0 −101
Original line number Diff line number Diff line 
/* ehci-lpm.c EHCI HCD LPM support code

 * Copyright (c) 2008 - 2010,  Intel Corporation.

 * Author: Jacob Pan <jacob.jun.pan@intel.com>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/



/* this file is part of ehci-hcd.c */



static int ehci_lpm_set_da(struct ehci_hcd *ehci, int dev_addr, int port_num)

{

	u32 __iomem portsc;



	ehci_dbg(ehci, "set dev address %d for port %d\n", dev_addr, port_num);

	if (port_num > HCS_N_PORTS(ehci->hcs_params)) {

		ehci_dbg(ehci, "invalid port number %d\n", port_num);

		return -ENODEV;

	}

	portsc = ehci_readl(ehci, &ehci->regs->port_status[port_num-1]);

	portsc &= ~PORT_DEV_ADDR;

	portsc |= dev_addr<<25;

	ehci_writel(ehci, portsc, &ehci->regs->port_status[port_num-1]);

	return 0;

}



/*

 * this function is used to check if the device support LPM

 * if yes, mark the PORTSC register with PORT_LPM bit

 */

static int ehci_lpm_check(struct ehci_hcd *ehci, int port)

{

	u32 __iomem	*portsc ;

	u32 val32;

	int retval;



	portsc = &ehci->regs->port_status[port-1];

	val32 = ehci_readl(ehci, portsc);

	if (!(val32 & PORT_DEV_ADDR)) {

		ehci_dbg(ehci, "LPM: no device attached\n");

		return -ENODEV;

	}

	val32 |= PORT_LPM;

	ehci_writel(ehci, val32, portsc);

	msleep(5);

	val32 |= PORT_SUSPEND;

	ehci_dbg(ehci, "Sending LPM 0x%08x to port %d\n", val32, port);

	ehci_writel(ehci, val32, portsc);

	/* wait for ACK */

	msleep(10);

	retval = handshake(ehci, &ehci->regs->port_status[port-1], PORT_SSTS,

			PORTSC_SUSPEND_STS_ACK, 125);

	dbg_port(ehci, "LPM", port, val32);

	if (retval != -ETIMEDOUT) {

		ehci_dbg(ehci, "LPM: device ACK for LPM\n");

		val32 |= PORT_LPM;

		/*

		 * now device should be in L1 sleep, let's wake up the device

		 * so that we can complete enumeration.

		 */

		ehci_writel(ehci, val32, portsc);

		msleep(10);

		val32 |= PORT_RESUME;

		ehci_writel(ehci, val32, portsc);

	} else {

		ehci_dbg(ehci, "LPM: device does not ACK, disable LPM %d\n",

			retval);

		val32 &= ~PORT_LPM;

		retval = -ETIMEDOUT;

		ehci_writel(ehci, val32, portsc);

	}



	return retval;

}



static int __maybe_unused ehci_update_device(struct usb_hcd *hcd,

		struct usb_device *udev)

{

	struct ehci_hcd *ehci = hcd_to_ehci(hcd);

	int rc = 0;



	if (!udev->parent) /* udev is root hub itself, impossible */

		rc = -1;

	/* we only support lpm device connected to root hub yet */

	if (ehci->has_lpm && !udev->parent->parent) {

		rc = ehci_lpm_set_da(ehci, udev->devnum, udev->portnum);

		if (!rc)

			rc = ehci_lpm_check(ehci, udev->portnum);

	}

	return rc;

}

drivers/usb/host/ehci-pci.c

+1 −12
Original line number Diff line number Diff line
@@ -202,11 +202,6 @@ static int ehci_pci_setup(struct usb_hcd *hcd) 
		break;

	case PCI_VENDOR_ID_INTEL:

		ehci->need_io_watchdog = 0;

		if (pdev->device == 0x0806 || pdev->device == 0x0811

				|| pdev->device == 0x0829) {

			ehci_info(ehci, "disable lpm for langwell/penwell\n");

			ehci->has_lpm = 0;

		}

		break;

	case PCI_VENDOR_ID_NVIDIA:

		switch (pdev->device) {
@@ -216,8 +211,7 @@ static int ehci_pci_setup(struct usb_hcd *hcd) 
		 * devices with PPCD enabled.

		 */

		case 0x0d9d:

			ehci_info(ehci, "disable lpm/ppcd for nvidia mcp89");

			ehci->has_lpm = 0;

			ehci_info(ehci, "disable ppcd for nvidia mcp89\n");

			ehci->has_ppcd = 0;

			ehci->command &= ~CMD_PPCEE;

			break;
@@ -425,11 +419,6 @@ static const struct hc_driver ehci_pci_hc_driver = { 
	.relinquish_port =	ehci_relinquish_port,

	.port_handed_over =	ehci_port_handed_over,



	/*

	 * call back when device connected and addressed

	 */

	.update_device =	ehci_update_device,



	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,

};