USB: don't explicitly reenable root-hub status interrupts

This patch (as1069b) 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>

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index e68fef5361d20d4f999b82b106ea13117e6119c8..bf10e9c4195e04eb473e15f65d17903b7afde935 100644 (file)
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -924,15 +924,6 @@ static int register_root_hub(struct usb_hcd *hcd)
        return retval;
 }
 
-void usb_enable_root_hub_irq (struct usb_bus *bus)
-{
-       struct usb_hcd *hcd;
-
-       hcd = container_of (bus, struct usb_hcd, self);
-       if (hcd->driver->hub_irq_enable && hcd->state != HC_STATE_HALT)
-               hcd->driver->hub_irq_enable (hcd);
-}
-
 
 /*-------------------------------------------------------------------------*/
 

diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index 3ba258eb05de0bce323796f20752d2779414f735..1e4b81e9eb5034a06c1b85406f0dbaf3da7f77a9 100644 (file)
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -210,8 +210,6 @@ struct hc_driver {
        int     (*bus_suspend)(struct usb_hcd *);
        int     (*bus_resume)(struct usb_hcd *);
        int     (*start_port_reset)(struct usb_hcd *, unsigned port_num);
-       void    (*hub_irq_enable)(struct usb_hcd *);
-               /* Needed only if port-change IRQs are level-triggered */
 
                /* force handover of high-speed port to full-speed companion */
        void    (*relinquish_port)(struct usb_hcd *, int);

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 1e23e360ea91fec68a24aeda683ab1d8d19c0601..5a338a5d4fe7e3c885232b732513e9ef6fce29a8 100644 (file)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2001,8 +2001,6 @@ int usb_port_resume(struct usb_device *udev)
        }
 
        clear_bit(port1, hub->busy_bits);
-       if (!hub->hdev->parent && !hub->busy_bits[0])
-               usb_enable_root_hub_irq(hub->hdev->bus);
 
        if (status == 0)
                status = finish_port_resume(udev);
@@ -2918,11 +2916,6 @@ static void hub_events(void)
 
                hub->activating = 0;
 
-               /* If this is a root hub, tell the HCD it's okay to
-                * re-enable port-change interrupts now. */
-               if (!hdev->parent && !hub->busy_bits[0])
-                       usb_enable_root_hub_irq(hdev->bus);
-
 loop_autopm:
                /* Allow autosuspend if we're not going to run again */
                if (list_empty(&hub->event_list))
@@ -3148,8 +3141,6 @@ int usb_reset_device(struct usb_device *udev)
                        break;
        }
        clear_bit(port1, parent_hub->busy_bits);
-       if (!parent_hdev->parent && !parent_hub->busy_bits[0])
-               usb_enable_root_hub_irq(parent_hdev->bus);
 
        if (ret < 0)
                goto re_enumerate;

diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index e534f9de0f05f9bbfc20c4f9938cb29c66a31f7a..c96db1153dcf6d595d2e42fc3bc3c18899f7b187 100644 (file)
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -261,7 +261,6 @@ static const struct hc_driver ohci_at91_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-au1xxx.c b/drivers/usb/host/ohci-au1xxx.c
index f90fe0c7373f046d7677d48350e177731daef514..1b9abdba920b9d18a8a53723a8eabc58342eaf0d 100644 (file)
--- a/drivers/usb/host/ohci-au1xxx.c
+++ b/drivers/usb/host/ohci-au1xxx.c
@@ -288,7 +288,6 @@ static const struct hc_driver ohci_au1xxx_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-ep93xx.c b/drivers/usb/host/ohci-ep93xx.c
index 5adaf36e47d05627dd1d9a884895ceaa28608aef..06aadfb0ec29a4683830a1d47191174e3f99b500 100644 (file)
--- a/drivers/usb/host/ohci-ep93xx.c
+++ b/drivers/usb/host/ohci-ep93xx.c
@@ -135,7 +135,6 @@ static struct hc_driver ohci_ep93xx_hc_driver = {
        .get_frame_number       = ohci_get_frame,
        .hub_status_data        = ohci_hub_status_data,
        .hub_control            = ohci_hub_control,
-       .hub_irq_enable         = ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend            = ohci_bus_suspend,
        .bus_resume             = ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index 355a82f2527425ba6ba8f71d993c3cde92335b3f..5be3bb3e6a9d791aa6262af9e429f724f20066f3 100644 (file)
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -36,18 +36,6 @@
 
 /*-------------------------------------------------------------------------*/
 
-/* hcd->hub_irq_enable() */
-static void ohci_rhsc_enable (struct usb_hcd *hcd)
-{
-       struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
-
-       spin_lock_irq(&ohci->lock);
-       if (!ohci->autostop)
-               del_timer(&hcd->rh_timer);      /* Prevent next poll */
-       ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
-       spin_unlock_irq(&ohci->lock);
-}
-
 #define OHCI_SCHED_ENABLES \
        (OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
 
@@ -374,18 +362,28 @@ static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
                int any_connected)
 {
        int     poll_rh = 1;
+       int     rhsc;
 
+       rhsc = ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC;
        switch (ohci->hc_control & OHCI_CTRL_HCFS) {
 
        case OHCI_USB_OPER:
-               /* keep on polling until we know a device is connected
-                * and RHSC is enabled */
+               /* If no status changes are pending, enable status-change
+                * interrupts.
+                */
+               if (!rhsc && !changed) {
+                       rhsc = OHCI_INTR_RHSC;
+                       ohci_writel(ohci, rhsc, &ohci->regs->intrenable);
+               }
+
+               /* Keep on polling until we know a device is connected
+                * and RHSC is enabled, or until we autostop.
+                */
                if (!ohci->autostop) {
                        if (any_connected ||
                                        !device_may_wakeup(&ohci_to_hcd(ohci)
                                                ->self.root_hub->dev)) {
-                               if (ohci_readl(ohci, &ohci->regs->intrenable) &
-                                               OHCI_INTR_RHSC)
+                               if (rhsc)
                                        poll_rh = 0;
                        } else {
                                ohci->autostop = 1;
@@ -398,12 +396,13 @@ static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
                                ohci->autostop = 0;
                                ohci->next_statechange = jiffies +
                                                STATECHANGE_DELAY;
-                       } else if (time_after_eq(jiffies,
+                       } else if (rhsc && time_after_eq(jiffies,
                                                ohci->next_statechange)
                                        && !ohci->ed_rm_list
                                        && !(ohci->hc_control &
                                                OHCI_SCHED_ENABLES)) {
                                ohci_rh_suspend(ohci, 1);
+                               poll_rh = 0;
                        }
                }
                break;
@@ -417,6 +416,12 @@ static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
                        else
                                usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
                } else {
+                       if (!rhsc && (ohci->autostop ||
+                                       ohci_to_hcd(ohci)->self.root_hub->
+                                               do_remote_wakeup))
+                               ohci_writel(ohci, OHCI_INTR_RHSC,
+                                               &ohci->regs->intrenable);
+
                        /* everything is idle, no need for polling */
                        poll_rh = 0;
                }
@@ -438,12 +443,16 @@ static inline int ohci_rh_resume(struct ohci_hcd *ohci)
 static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
                int any_connected)
 {
-       int     poll_rh = 1;
-
-       /* keep on polling until RHSC is enabled */
+       /* If RHSC is enabled, don't poll */
        if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
-               poll_rh = 0;
-       return poll_rh;
+               return 0;
+
+       /* If no status changes are pending, enable status-change interrupts */
+       if (!changed) {
+               ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
+               return 0;
+       }
+       return 1;
 }
 
 #endif /* CONFIG_PM */

diff --git a/drivers/usb/host/ohci-lh7a404.c b/drivers/usb/host/ohci-lh7a404.c
index 13c12ed22252cc90c1ace3319410819a5e111937..96d14fa1d8331b7ee2a587d9138246b99e4bceec 100644 (file)
--- a/drivers/usb/host/ohci-lh7a404.c
+++ b/drivers/usb/host/ohci-lh7a404.c
@@ -193,7 +193,6 @@ static const struct hc_driver ohci_lh7a404_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-omap.c b/drivers/usb/host/ohci-omap.c
index 3a7c24c03671199680a435cd93370b415bcfa52c..6859fb5f1d6f6a5d2f9dd29b0c3d063697c15233 100644 (file)
--- a/drivers/usb/host/ohci-omap.c
+++ b/drivers/usb/host/ohci-omap.c
@@ -466,7 +466,6 @@ static const struct hc_driver ohci_omap_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-pci.c b/drivers/usb/host/ohci-pci.c
index 4696cc912e16203540a5185568a27e02bb7c15e2..3bf175d95a2303b17d80a3561fc38a727ce13c84 100644 (file)
--- a/drivers/usb/host/ohci-pci.c
+++ b/drivers/usb/host/ohci-pci.c
@@ -327,7 +327,6 @@ static const struct hc_driver ohci_pci_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-pnx4008.c b/drivers/usb/host/ohci-pnx4008.c
index 28b458f20cc3013749503821119e5e741e58a85f..664f07ee87320e2a568c727d95bbf82b8d446894 100644 (file)
--- a/drivers/usb/host/ohci-pnx4008.c
+++ b/drivers/usb/host/ohci-pnx4008.c
@@ -280,7 +280,6 @@ static const struct hc_driver ohci_pnx4008_hc_driver = {
         */
        .hub_status_data = ohci_hub_status_data,
        .hub_control = ohci_hub_control,
-       .hub_irq_enable = ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend = ohci_bus_suspend,
        .bus_resume = ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-pnx8550.c b/drivers/usb/host/ohci-pnx8550.c
index 605d59cba28e79d46bbbb3215cfc9ccd1b6f6a5b..28467e288a93d54607c7cb244e1e904dc6136395 100644 (file)
--- a/drivers/usb/host/ohci-pnx8550.c
+++ b/drivers/usb/host/ohci-pnx8550.c
@@ -201,7 +201,6 @@ static const struct hc_driver ohci_pnx8550_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-ppc-of.c b/drivers/usb/host/ohci-ppc-of.c
index a6725279122315bf7566b255164d29c7f8130bbd..50e55db13636ece797f64ae65e1a01a58800fabe 100644 (file)
--- a/drivers/usb/host/ohci-ppc-of.c
+++ b/drivers/usb/host/ohci-ppc-of.c
@@ -72,7 +72,6 @@ static const struct hc_driver ohci_ppc_of_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-ppc-soc.c b/drivers/usb/host/ohci-ppc-soc.c
index 523c30125577d39a8c24287ce30ae2b2532929e2..cd3398b675b2dea8c2402fd2178cee58c23a52e4 100644 (file)
--- a/drivers/usb/host/ohci-ppc-soc.c
+++ b/drivers/usb/host/ohci-ppc-soc.c
@@ -172,7 +172,6 @@ static const struct hc_driver ohci_ppc_soc_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-ps3.c b/drivers/usb/host/ohci-ps3.c
index c1935ae537f80a90779d6eaea502dd4d02ee267d..bfdeb0d22d050576755f6d1054d9d4b561bb7e3a 100644 (file)
--- a/drivers/usb/host/ohci-ps3.c
+++ b/drivers/usb/host/ohci-ps3.c
@@ -68,7 +68,6 @@ static const struct hc_driver ps3_ohci_hc_driver = {
        .get_frame_number       = ohci_get_frame,
        .hub_status_data        = ohci_hub_status_data,
        .hub_control            = ohci_hub_control,
-       .hub_irq_enable         = ohci_rhsc_enable,
        .start_port_reset       = ohci_start_port_reset,
 #if defined(CONFIG_PM)
        .bus_suspend            = ohci_bus_suspend,

diff --git a/drivers/usb/host/ohci-pxa27x.c b/drivers/usb/host/ohci-pxa27x.c
index d4ee27d92be8fd69874f50b1e16785257a1066c1..70b0d4b459e753bf13ed622eb32fd7b458c9d38c 100644 (file)
--- a/drivers/usb/host/ohci-pxa27x.c
+++ b/drivers/usb/host/ohci-pxa27x.c
@@ -298,7 +298,6 @@ static const struct hc_driver ohci_pxa27x_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef  CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-s3c2410.c b/drivers/usb/host/ohci-s3c2410.c
index ead4772f0f277c0f1447636e682392612ca65aa3..a73d2ff322e28d862184ad83188da0302386f61c 100644 (file)
--- a/drivers/usb/host/ohci-s3c2410.c
+++ b/drivers/usb/host/ohci-s3c2410.c
@@ -466,7 +466,6 @@ static const struct hc_driver ohci_s3c2410_hc_driver = {
         */
        .hub_status_data =      ohci_s3c2410_hub_status_data,
        .hub_control =          ohci_s3c2410_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-sa1111.c b/drivers/usb/host/ohci-sa1111.c
index 0f48f2d992263f199ad889e31f8e0f3bf0c4f48d..99438c65981b4f8cd98e87066092c2ea1b9251b3 100644 (file)
--- a/drivers/usb/host/ohci-sa1111.c
+++ b/drivers/usb/host/ohci-sa1111.c
@@ -231,7 +231,6 @@ static const struct hc_driver ohci_sa1111_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-sh.c b/drivers/usb/host/ohci-sh.c
index e7ee607278fece8b92570beb5b839e74ca8aa2db..60f03cc7ec4f20a4f80d228b59faebe715ae1148 100644 (file)
--- a/drivers/usb/host/ohci-sh.c
+++ b/drivers/usb/host/ohci-sh.c
@@ -68,7 +68,6 @@ static const struct hc_driver ohci_sh_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-sm501.c b/drivers/usb/host/ohci-sm501.c
index 4a11e181601778d13abc58e8694efe3f225be8b4..77204f001b9a6eefcce60ee54b241aa364013f38 100644 (file)
--- a/drivers/usb/host/ohci-sm501.c
+++ b/drivers/usb/host/ohci-sm501.c
@@ -75,7 +75,6 @@ static const struct hc_driver ohci_sm501_hc_driver = {
         */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
-       .hub_irq_enable =       ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,

diff --git a/drivers/usb/host/ohci-ssb.c b/drivers/usb/host/ohci-ssb.c
index 7275186db31556baf8278ec300da9d0d8600a98f..c4265caec78023993e62607c5be548560d34fbf4 100644 (file)
--- a/drivers/usb/host/ohci-ssb.c
+++ b/drivers/usb/host/ohci-ssb.c
@@ -81,7 +81,6 @@ static const struct hc_driver ssb_ohci_hc_driver = {
 
        .hub_status_data        = ohci_hub_status_data,
        .hub_control            = ohci_hub_control,
-       .hub_irq_enable         = ohci_rhsc_enable,
 #ifdef CONFIG_PM
        .bus_suspend            = ohci_bus_suspend,
        .bus_resume             = ohci_bus_resume,

diff --git a/drivers/usb/host/u132-hcd.c b/drivers/usb/host/u132-hcd.c
index 9b6323f768b242523495d352134f5533c423566d..f29307405bb36aa45ef4a764f9d483d99dfeef6e 100644 (file)
--- a/drivers/usb/host/u132-hcd.c
+++ b/drivers/usb/host/u132-hcd.c
@@ -2934,16 +2934,6 @@ static int u132_start_port_reset(struct usb_hcd *hcd, unsigned port_num)
                return 0;
 }
 
-static void u132_hub_irq_enable(struct usb_hcd *hcd)
-{
-       struct u132 *u132 = hcd_to_u132(hcd);
-       if (u132->going > 1) {
-               dev_err(&u132->platform_dev->dev, "device has been removed %d\n"
-                       , u132->going);
-       } else if (u132->going > 0)
-               dev_err(&u132->platform_dev->dev, "device is being removed\n");
-}
-
 
 #ifdef CONFIG_PM
 static int u132_bus_suspend(struct usb_hcd *hcd)
@@ -2995,7 +2985,6 @@ static struct hc_driver u132_hc_driver = {
        .bus_suspend = u132_bus_suspend,
        .bus_resume = u132_bus_resume,
        .start_port_reset = u132_start_port_reset,
-       .hub_irq_enable = u132_hub_irq_enable,
 };
 
 /*