![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>
216 lines
4.9 KiB
C
216 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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* (C) Copyright 2003-2005 MontaVista Software Inc.
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*
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* Bus Glue for PPC On-Chip OHCI driver
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* Tested on Freescale MPC5200 and IBM STB04xxx
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*
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* Modified by Dale Farnsworth <dale@farnsworth.org> from ohci-sa1111.c
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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/platform_device.h>
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#include <linux/signal.h>
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/* configure so an HC device and id are always provided */
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/* always called with process context; sleeping is OK */
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/**
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* usb_hcd_ppc_soc_probe - initialize On-Chip HCDs
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* Context: !in_interrupt()
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*
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* Allocates basic resources for this USB host controller.
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*
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* Store this function in the HCD's struct pci_driver as probe().
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*/
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static int usb_hcd_ppc_soc_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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struct ohci_hcd *ohci;
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struct resource *res;
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int irq;
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pr_debug("initializing PPC-SOC USB Controller\n");
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res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
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if (!res) {
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pr_debug(__FILE__ ": no irq\n");
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return -ENODEV;
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}
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irq = res->start;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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pr_debug(__FILE__ ": no reg addr\n");
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return -ENODEV;
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}
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hcd = usb_create_hcd(driver, &pdev->dev, "PPC-SOC USB");
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if (!hcd)
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return -ENOMEM;
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hcd->rsrc_start = res->start;
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hcd->rsrc_len = res->end - res->start + 1;
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if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
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pr_debug(__FILE__ ": request_mem_region failed\n");
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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) {
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pr_debug(__FILE__ ": ioremap failed\n");
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retval = -ENOMEM;
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goto err2;
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}
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ohci = hcd_to_ohci(hcd);
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ohci->flags |= OHCI_QUIRK_BE_MMIO | OHCI_QUIRK_BE_DESC;
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#ifdef CONFIG_PPC_MPC52xx
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/* MPC52xx doesn't need frame_no shift */
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ohci->flags |= OHCI_QUIRK_FRAME_NO;
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#endif
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ohci_hcd_init(ohci);
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retval = usb_add_hcd(hcd, irq, IRQF_DISABLED);
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if (retval == 0)
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return retval;
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pr_debug("Removing PPC-SOC USB Controller\n");
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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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/* may be called without controller electrically present */
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/* may be called with controller, bus, and devices active */
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/**
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* usb_hcd_ppc_soc_remove - shutdown processing for On-Chip HCDs
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* @pdev: USB Host Controller being removed
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* Context: !in_interrupt()
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*
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* Reverses the effect of usb_hcd_ppc_soc_probe().
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* It is always called from a thread
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* context, normally "rmmod", "apmd", or something similar.
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*
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*/
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static void usb_hcd_ppc_soc_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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pr_debug("stopping PPC-SOC USB Controller\n");
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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
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ohci_ppc_soc_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", ohci_to_hcd(ohci)->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 const struct hc_driver ohci_ppc_soc_hc_driver = {
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.description = hcd_name,
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.hcd_priv_size = sizeof(struct ohci_hcd),
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/*
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* generic hardware linkage
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*/
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.irq = ohci_irq,
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.flags = HCD_USB11 | HCD_MEMORY,
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/*
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* basic lifecycle operations
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*/
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.start = ohci_ppc_soc_start,
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.stop = ohci_stop,
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.shutdown = ohci_shutdown,
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/*
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* managing i/o requests and associated device resources
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*/
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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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/*
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* scheduling support
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*/
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.get_frame_number = ohci_get_frame,
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/*
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* root hub support
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*/
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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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static int ohci_hcd_ppc_soc_drv_probe(struct platform_device *pdev)
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{
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int ret;
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if (usb_disabled())
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return -ENODEV;
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ret = usb_hcd_ppc_soc_probe(&ohci_ppc_soc_hc_driver, pdev);
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return ret;
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}
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static int ohci_hcd_ppc_soc_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_ppc_soc_remove(hcd, pdev);
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return 0;
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}
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static struct platform_driver ohci_hcd_ppc_soc_driver = {
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.probe = ohci_hcd_ppc_soc_drv_probe,
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.remove = ohci_hcd_ppc_soc_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_ppc_soc_drv_suspend,*/
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/*.resume = ohci_hcd_ppc_soc_drv_resume,*/
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#endif
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.driver = {
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.name = "ppc-soc-ohci",
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.owner = THIS_MODULE,
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},
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};
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MODULE_ALIAS("platform:ppc-soc-ohci");
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