![Alan Stern](/assets/img/avatar_default.png)
This patch (as1069c) changes the way OHCI root-hub status-change interrupts are enabled. Currently a special HCD method, hub_irq_enable(), is called when the hub driver is finished using a root hub. This approach turns out to be subject to races, resulting in unnecessary polling. The patch does away with the method entirely. Instead, the driver automatically enables the RHSC interrupt when no more status changes are present. This scheme is safe with controllers using level-triggered semantics for their interrupt flags. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
215 lines
4.9 KiB
C
215 lines
4.9 KiB
C
/*
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* OHCI HCD (Host Controller Driver) for USB.
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*
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* (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
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* (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
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* (C) Copyright 2002 Hewlett-Packard Company
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*
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* Bus Glue for ep93xx.
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*
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* Written by Christopher Hoover <ch@hpl.hp.com>
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* Based on fragments of previous driver by Russell King et al.
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*
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* Modified for LH7A404 from ohci-sa1111.c
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* by Durgesh Pattamatta <pattamattad@sharpsec.com>
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*
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* Modified for pxa27x from ohci-lh7a404.c
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* by Nick Bane <nick@cecomputing.co.uk> 26-8-2004
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*
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* Modified for ep93xx from ohci-pxa27x.c
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* by Lennert Buytenhek <buytenh@wantstofly.org> 28-2-2006
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* Based on an earlier driver by Ray Lehtiniemi
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*
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* This file is licenced under the GPL.
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*/
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#include <linux/clk.h>
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#include <linux/device.h>
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#include <linux/signal.h>
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#include <linux/platform_device.h>
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#include <mach/hardware.h>
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static struct clk *usb_host_clock;
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static void ep93xx_start_hc(struct device *dev)
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{
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clk_enable(usb_host_clock);
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}
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static void ep93xx_stop_hc(struct device *dev)
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{
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clk_disable(usb_host_clock);
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}
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static int usb_hcd_ep93xx_probe(const struct hc_driver *driver,
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struct platform_device *pdev)
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{
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int retval;
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struct usb_hcd *hcd;
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if (pdev->resource[1].flags != IORESOURCE_IRQ) {
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pr_debug("resource[1] is not IORESOURCE_IRQ");
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return -ENOMEM;
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}
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hcd = usb_create_hcd(driver, &pdev->dev, "ep93xx");
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if (hcd == NULL)
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return -ENOMEM;
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hcd->rsrc_start = pdev->resource[0].start;
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hcd->rsrc_len = pdev->resource[0].end - pdev->resource[0].start + 1;
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if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
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usb_put_hcd(hcd);
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retval = -EBUSY;
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goto err1;
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}
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hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
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if (hcd->regs == NULL) {
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pr_debug("ioremap failed");
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retval = -ENOMEM;
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goto err2;
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}
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usb_host_clock = clk_get(&pdev->dev, "usb_host");
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ep93xx_start_hc(&pdev->dev);
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ohci_hcd_init(hcd_to_ohci(hcd));
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retval = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_DISABLED);
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if (retval == 0)
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return retval;
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ep93xx_stop_hc(&pdev->dev);
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iounmap(hcd->regs);
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err2:
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release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
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err1:
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usb_put_hcd(hcd);
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return retval;
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}
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static void usb_hcd_ep93xx_remove(struct usb_hcd *hcd,
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struct platform_device *pdev)
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{
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usb_remove_hcd(hcd);
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ep93xx_stop_hc(&pdev->dev);
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clk_put(usb_host_clock);
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iounmap(hcd->regs);
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release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
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usb_put_hcd(hcd);
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}
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static int __devinit ohci_ep93xx_start(struct usb_hcd *hcd)
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{
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struct ohci_hcd *ohci = hcd_to_ohci(hcd);
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int ret;
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if ((ret = ohci_init(ohci)) < 0)
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return ret;
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if ((ret = ohci_run(ohci)) < 0) {
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err("can't start %s", hcd->self.bus_name);
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ohci_stop(hcd);
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return ret;
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}
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return 0;
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}
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static struct hc_driver ohci_ep93xx_hc_driver = {
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.description = hcd_name,
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.product_desc = "EP93xx OHCI",
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.hcd_priv_size = sizeof(struct ohci_hcd),
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.irq = ohci_irq,
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.flags = HCD_USB11 | HCD_MEMORY,
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.start = ohci_ep93xx_start,
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.stop = ohci_stop,
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.shutdown = ohci_shutdown,
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.urb_enqueue = ohci_urb_enqueue,
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.urb_dequeue = ohci_urb_dequeue,
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.endpoint_disable = ohci_endpoint_disable,
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.get_frame_number = ohci_get_frame,
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.hub_status_data = ohci_hub_status_data,
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.hub_control = ohci_hub_control,
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#ifdef CONFIG_PM
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.bus_suspend = ohci_bus_suspend,
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.bus_resume = ohci_bus_resume,
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#endif
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.start_port_reset = ohci_start_port_reset,
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};
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extern int usb_disabled(void);
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static int ohci_hcd_ep93xx_drv_probe(struct platform_device *pdev)
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{
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int ret;
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ret = -ENODEV;
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if (!usb_disabled())
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ret = usb_hcd_ep93xx_probe(&ohci_ep93xx_hc_driver, pdev);
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return ret;
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}
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static int ohci_hcd_ep93xx_drv_remove(struct platform_device *pdev)
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{
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struct usb_hcd *hcd = platform_get_drvdata(pdev);
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usb_hcd_ep93xx_remove(hcd, pdev);
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return 0;
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}
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#ifdef CONFIG_PM
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static int ohci_hcd_ep93xx_drv_suspend(struct platform_device *pdev, pm_message_t state)
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{
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struct usb_hcd *hcd = platform_get_drvdata(pdev);
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struct ohci_hcd *ohci = hcd_to_ohci(hcd);
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if (time_before(jiffies, ohci->next_statechange))
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msleep(5);
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ohci->next_statechange = jiffies;
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ep93xx_stop_hc(&pdev->dev);
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hcd->state = HC_STATE_SUSPENDED;
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return 0;
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}
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static int ohci_hcd_ep93xx_drv_resume(struct platform_device *pdev)
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{
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struct usb_hcd *hcd = platform_get_drvdata(pdev);
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struct ohci_hcd *ohci = hcd_to_ohci(hcd);
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int status;
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if (time_before(jiffies, ohci->next_statechange))
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msleep(5);
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ohci->next_statechange = jiffies;
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ep93xx_start_hc(&pdev->dev);
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ohci_finish_controller_resume(hcd);
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return 0;
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}
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#endif
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static struct platform_driver ohci_hcd_ep93xx_driver = {
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.probe = ohci_hcd_ep93xx_drv_probe,
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.remove = ohci_hcd_ep93xx_drv_remove,
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.shutdown = usb_hcd_platform_shutdown,
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#ifdef CONFIG_PM
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.suspend = ohci_hcd_ep93xx_drv_suspend,
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.resume = ohci_hcd_ep93xx_drv_resume,
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#endif
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.driver = {
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.name = "ep93xx-ohci",
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.owner = THIS_MODULE,
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},
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};
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MODULE_ALIAS("platform:ep93xx-ohci");
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