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linux-next/drivers/usb/host/ohci-hub.c
Shigeru Yoshida b2685bdacd ohci-hcd: Fix race condition caused by ohci_urb_enqueue() and io_watchdog_func() 
Running io_watchdog_func() while ohci_urb_enqueue() is running can
cause a race condition where ohci->prev_frame_no is corrupted and the
watchdog can mis-detect following error:

  ohci-platform 664a0800.usb: frame counter not updating; disabled
  ohci-platform 664a0800.usb: HC died; cleaning up

Specifically, following scenario causes a race condition:

  1. ohci_urb_enqueue() calls spin_lock_irqsave(&ohci->lock, flags)
     and enters the critical section
  2. ohci_urb_enqueue() calls timer_pending(&ohci->io_watchdog) and it
     returns false
  3. ohci_urb_enqueue() sets ohci->prev_frame_no to a frame number
     read by ohci_frame_no(ohci)
  4. ohci_urb_enqueue() schedules io_watchdog_func() with mod_timer()
  5. ohci_urb_enqueue() calls spin_unlock_irqrestore(&ohci->lock,
     flags) and exits the critical section
  6. Later, ohci_urb_enqueue() is called
  7. ohci_urb_enqueue() calls spin_lock_irqsave(&ohci->lock, flags)
     and enters the critical section
  8. The timer scheduled on step 4 expires and io_watchdog_func() runs
  9. io_watchdog_func() calls spin_lock_irqsave(&ohci->lock, flags)
     and waits on it because ohci_urb_enqueue() is already in the
     critical section on step 7
 10. ohci_urb_enqueue() calls timer_pending(&ohci->io_watchdog) and it
     returns false
 11. ohci_urb_enqueue() sets ohci->prev_frame_no to new frame number
     read by ohci_frame_no(ohci) because the frame number proceeded
     between step 3 and 6
 12. ohci_urb_enqueue() schedules io_watchdog_func() with mod_timer()
 13. ohci_urb_enqueue() calls spin_unlock_irqrestore(&ohci->lock,
     flags) and exits the critical section, then wake up
     io_watchdog_func() which is waiting on step 9
 14. io_watchdog_func() enters the critical section
 15. io_watchdog_func() calls ohci_frame_no(ohci) and set frame_no
     variable to the frame number
 16. io_watchdog_func() compares frame_no and ohci->prev_frame_no

On step 16, because this calling of io_watchdog_func() is scheduled on
step 4, the frame number set in ohci->prev_frame_no is expected to the
number set on step 3.  However, ohci->prev_frame_no is overwritten on
step 11.  Because step 16 is executed soon after step 11, the frame
number might not proceed, so ohci->prev_frame_no must equals to
frame_no.

To address above scenario, this patch introduces a special sentinel
value IO_WATCHDOG_OFF and set this value to ohci->prev_frame_no when
the watchdog is not pending or running.  When ohci_urb_enqueue()
schedules the watchdog (step 4 and 12 above), it compares
ohci->prev_frame_no to IO_WATCHDOG_OFF so that ohci->prev_frame_no is
not overwritten while io_watchdog_func() is running.

Signed-off-by: Shigeru Yoshida <Shigeru.Yoshida@windriver.com>
Signed-off-by: Haiqing Bai <Haiqing.Bai@windriver.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-15 18:43:57 +01:00

800 lines
21 KiB
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// SPDX-License-Identifier: GPL-1.0+
/*
* OHCI HCD (Host Controller Driver) for USB.
*
* (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
* (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
*
* This file is licenced under GPL
*/
/*-------------------------------------------------------------------------*/
/*
* OHCI Root Hub ... the nonsharable stuff
*/
#define dbg_port(hc,label,num,value) \
ohci_dbg (hc, \
"%s roothub.portstatus [%d] " \
"= 0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
label, num, value, \
(value & RH_PS_PRSC) ? " PRSC" : "", \
(value & RH_PS_OCIC) ? " OCIC" : "", \
(value & RH_PS_PSSC) ? " PSSC" : "", \
(value & RH_PS_PESC) ? " PESC" : "", \
(value & RH_PS_CSC) ? " CSC" : "", \
\
(value & RH_PS_LSDA) ? " LSDA" : "", \
(value & RH_PS_PPS) ? " PPS" : "", \
(value & RH_PS_PRS) ? " PRS" : "", \
(value & RH_PS_POCI) ? " POCI" : "", \
(value & RH_PS_PSS) ? " PSS" : "", \
\
(value & RH_PS_PES) ? " PES" : "", \
(value & RH_PS_CCS) ? " CCS" : "" \
);
/*-------------------------------------------------------------------------*/
#define OHCI_SCHED_ENABLES \
(OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
static void update_done_list(struct ohci_hcd *);
static void ohci_work(struct ohci_hcd *);
#ifdef CONFIG_PM
static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
__releases(ohci->lock)
__acquires(ohci->lock)
{
int status = 0;
ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
switch (ohci->hc_control & OHCI_CTRL_HCFS) {
case OHCI_USB_RESUME:
ohci_dbg (ohci, "resume/suspend?\n");
ohci->hc_control &= ~OHCI_CTRL_HCFS;
ohci->hc_control |= OHCI_USB_RESET;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
/* FALL THROUGH */
case OHCI_USB_RESET:
status = -EBUSY;
ohci_dbg (ohci, "needs reinit!\n");
goto done;
case OHCI_USB_SUSPEND:
if (!ohci->autostop) {
ohci_dbg (ohci, "already suspended\n");
goto done;
}
}
ohci_dbg (ohci, "%s root hub\n",
autostop ? "auto-stop" : "suspend");
/* First stop any processing */
if (!autostop && (ohci->hc_control & OHCI_SCHED_ENABLES)) {
ohci->hc_control &= ~OHCI_SCHED_ENABLES;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);
/* sched disables take effect on the next frame,
* then the last WDH could take 6+ msec
*/
ohci_dbg (ohci, "stopping schedules ...\n");
ohci->autostop = 0;
spin_unlock_irq (&ohci->lock);
msleep (8);
spin_lock_irq (&ohci->lock);
}
update_done_list(ohci);
ohci_work(ohci);
/*
* Some controllers don't handle "global" suspend properly if
* there are unsuspended ports. For these controllers, put all
* the enabled ports into suspend before suspending the root hub.
*/
if (ohci->flags & OHCI_QUIRK_GLOBAL_SUSPEND) {
__hc32 __iomem *portstat = ohci->regs->roothub.portstatus;
int i;
unsigned temp;
for (i = 0; i < ohci->num_ports; (++i, ++portstat)) {
temp = ohci_readl(ohci, portstat);
if ((temp & (RH_PS_PES | RH_PS_PSS)) ==
RH_PS_PES)
ohci_writel(ohci, RH_PS_PSS, portstat);
}
}
/* maybe resume can wake root hub */
if (ohci_to_hcd(ohci)->self.root_hub->do_remote_wakeup || autostop) {
ohci->hc_control |= OHCI_CTRL_RWE;
} else {
ohci_writel(ohci, OHCI_INTR_RHSC | OHCI_INTR_RD,
&ohci->regs->intrdisable);
ohci->hc_control &= ~OHCI_CTRL_RWE;
}
/* Suspend hub ... this is the "global (to this bus) suspend" mode,
* which doesn't imply ports will first be individually suspended.
*/
ohci->hc_control &= ~OHCI_CTRL_HCFS;
ohci->hc_control |= OHCI_USB_SUSPEND;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
/* no resumes until devices finish suspending */
if (!autostop) {
ohci->next_statechange = jiffies + msecs_to_jiffies (5);
ohci->autostop = 0;
ohci->rh_state = OHCI_RH_SUSPENDED;
}
done:
return status;
}
static inline struct ed *find_head (struct ed *ed)
{
/* for bulk and control lists */
while (ed->ed_prev)
ed = ed->ed_prev;
return ed;
}
/* caller has locked the root hub */
static int ohci_rh_resume (struct ohci_hcd *ohci)
__releases(ohci->lock)
__acquires(ohci->lock)
{
struct usb_hcd *hcd = ohci_to_hcd (ohci);
u32 temp, enables;
int status = -EINPROGRESS;
int autostopped = ohci->autostop;
ohci->autostop = 0;
ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
/* this can happen after resuming a swsusp snapshot */
if (ohci->rh_state != OHCI_RH_RUNNING) {
ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
ohci->hc_control);
status = -EBUSY;
/* this happens when pmcore resumes HC then root */
} else {
ohci_dbg (ohci, "duplicate resume\n");
status = 0;
}
} else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
case OHCI_USB_SUSPEND:
ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
ohci->hc_control |= OHCI_USB_RESUME;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
ohci_dbg (ohci, "%s root hub\n",
autostopped ? "auto-start" : "resume");
break;
case OHCI_USB_RESUME:
/* HCFS changes sometime after INTR_RD */
ohci_dbg(ohci, "%swakeup root hub\n",
autostopped ? "auto-" : "");
break;
case OHCI_USB_OPER:
/* this can happen after resuming a swsusp snapshot */
ohci_dbg (ohci, "snapshot resume? reinit\n");
status = -EBUSY;
break;
default: /* RESET, we lost power */
ohci_dbg (ohci, "lost power\n");
status = -EBUSY;
}
if (status == -EBUSY) {
if (!autostopped) {
spin_unlock_irq (&ohci->lock);
status = ohci_restart (ohci);
usb_root_hub_lost_power(hcd->self.root_hub);
spin_lock_irq (&ohci->lock);
}
return status;
}
if (status != -EINPROGRESS)
return status;
if (autostopped)
goto skip_resume;
spin_unlock_irq (&ohci->lock);
/* Some controllers (lucent erratum) need extra-long delays */
msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);
temp = ohci_readl (ohci, &ohci->regs->control);
temp &= OHCI_CTRL_HCFS;
if (temp != OHCI_USB_RESUME) {
ohci_err (ohci, "controller won't resume\n");
spin_lock_irq(&ohci->lock);
return -EBUSY;
}
/* disable old schedule state, reinit from scratch */
ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);
/* Sometimes PCI D3 suspend trashes frame timings ... */
periodic_reinit (ohci);
/*
* The following code is executed with ohci->lock held and
* irqs disabled if and only if autostopped is true. This
* will cause sparse to warn about a "context imbalance".
*/
skip_resume:
/* interrupts might have been disabled */
ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
if (ohci->ed_rm_list)
ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
/* Then re-enable operations */
ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
if (!autostopped)
msleep (3);
temp = ohci->hc_control;
temp &= OHCI_CTRL_RWC;
temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
ohci->hc_control = temp;
ohci_writel (ohci, temp, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
/* TRSMRCY */
if (!autostopped) {
msleep (10);
spin_lock_irq (&ohci->lock);
}
/* now ohci->lock is always held and irqs are always disabled */
/* keep it alive for more than ~5x suspend + resume costs */
ohci->next_statechange = jiffies + STATECHANGE_DELAY;
/* maybe turn schedules back on */
enables = 0;
temp = 0;
if (!ohci->ed_rm_list) {
if (ohci->ed_controltail) {
ohci_writel (ohci,
find_head (ohci->ed_controltail)->dma,
&ohci->regs->ed_controlhead);
enables |= OHCI_CTRL_CLE;
temp |= OHCI_CLF;
}
if (ohci->ed_bulktail) {
ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
&ohci->regs->ed_bulkhead);
enables |= OHCI_CTRL_BLE;
temp |= OHCI_BLF;
}
}
if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
if (enables) {
ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
ohci->hc_control |= enables;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
if (temp)
ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
(void) ohci_readl (ohci, &ohci->regs->control);
}
ohci->rh_state = OHCI_RH_RUNNING;
return 0;
}
static int ohci_bus_suspend (struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int rc;
spin_lock_irq (&ohci->lock);
if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
rc = -ESHUTDOWN;
else
rc = ohci_rh_suspend (ohci, 0);
spin_unlock_irq (&ohci->lock);
if (rc == 0) {
del_timer_sync(&ohci->io_watchdog);
ohci->prev_frame_no = IO_WATCHDOG_OFF;
}
return rc;
}
static int ohci_bus_resume (struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int rc;
if (time_before (jiffies, ohci->next_statechange))
msleep(5);
spin_lock_irq (&ohci->lock);
if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
rc = -ESHUTDOWN;
else
rc = ohci_rh_resume (ohci);
spin_unlock_irq (&ohci->lock);
/* poll until we know a device is connected or we autostop */
if (rc == 0)
usb_hcd_poll_rh_status(hcd);
return rc;
}
/* Carry out polling-, autostop-, and autoresume-related state changes */
static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
int any_connected, int rhsc_status)
{
int poll_rh = 1;
int rhsc_enable;
/* Some broken controllers never turn off RHSC in the interrupt
* status register. For their sake we won't re-enable RHSC
* interrupts if the interrupt bit is already active.
*/
rhsc_enable = ohci_readl(ohci, &ohci->regs->intrenable) &
OHCI_INTR_RHSC;
switch (ohci->hc_control & OHCI_CTRL_HCFS) {
case OHCI_USB_OPER:
/* If no status changes are pending, enable RHSC interrupts. */
if (!rhsc_enable && !rhsc_status && !changed) {
rhsc_enable = OHCI_INTR_RHSC;
ohci_writel(ohci, rhsc_enable, &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 (rhsc_enable)
poll_rh = 0;
} else {
ohci->autostop = 1;
ohci->next_statechange = jiffies + HZ;
}
/* if no devices have been attached for one second, autostop */
} else {
if (changed || any_connected) {
ohci->autostop = 0;
ohci->next_statechange = jiffies +
STATECHANGE_DELAY;
} else if (time_after_eq(jiffies,
ohci->next_statechange)
&& !ohci->ed_rm_list
&& !(ohci->hc_control &
OHCI_SCHED_ENABLES)) {
ohci_rh_suspend(ohci, 1);
if (rhsc_enable)
poll_rh = 0;
}
}
break;
case OHCI_USB_SUSPEND:
case OHCI_USB_RESUME:
/* if there is a port change, autostart or ask to be resumed */
if (changed) {
if (ohci->autostop)
ohci_rh_resume(ohci);
else
usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
/* If remote wakeup is disabled, stop polling */
} else if (!ohci->autostop &&
!ohci_to_hcd(ohci)->self.root_hub->
do_remote_wakeup) {
poll_rh = 0;
} else {
/* If no status changes are pending,
* enable RHSC interrupts
*/
if (!rhsc_enable && !rhsc_status) {
rhsc_enable = OHCI_INTR_RHSC;
ohci_writel(ohci, rhsc_enable,
&ohci->regs->intrenable);
}
/* Keep polling until RHSC is enabled */
if (rhsc_enable)
poll_rh = 0;
}
break;
}
return poll_rh;
}
#else /* CONFIG_PM */
static inline int ohci_rh_resume(struct ohci_hcd *ohci)
{
return 0;
}
/* Carry out polling-related state changes.
* autostop isn't used when CONFIG_PM is turned off.
*/
static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
int any_connected, int rhsc_status)
{
/* If RHSC is enabled, don't poll */
if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
return 0;
/* If status changes are pending, continue polling.
* Conversely, if no status changes are pending but the RHSC
* status bit was set, then RHSC may be broken so continue polling.
*/
if (changed || rhsc_status)
return 1;
/* It's safe to re-enable RHSC interrupts */
ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
return 0;
}
#endif /* CONFIG_PM */
/*-------------------------------------------------------------------------*/
/* build "status change" packet (one or two bytes) from HC registers */
int ohci_hub_status_data(struct usb_hcd *hcd, char *buf)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int i, changed = 0, length = 1;
int any_connected = 0;
int rhsc_status;
unsigned long flags;
spin_lock_irqsave (&ohci->lock, flags);
if (!HCD_HW_ACCESSIBLE(hcd))
goto done;
/* undocumented erratum seen on at least rev D */
if ((ohci->flags & OHCI_QUIRK_AMD756)
&& (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
/* retry later; "should not happen" */
goto done;
}
/* init status */
if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
buf [0] = changed = 1;
else
buf [0] = 0;
if (ohci->num_ports > 7) {
buf [1] = 0;
length++;
}
/* Clear the RHSC status flag before reading the port statuses */
ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrstatus);
rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
OHCI_INTR_RHSC;
/* look at each port */
for (i = 0; i < ohci->num_ports; i++) {
u32 status = roothub_portstatus (ohci, i);
/* can't autostop if ports are connected */
any_connected |= (status & RH_PS_CCS);
if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
| RH_PS_OCIC | RH_PS_PRSC)) {
changed = 1;
if (i < 7)
buf [0] |= 1 << (i + 1);
else
buf [1] |= 1 << (i - 7);
}
}
if (ohci_root_hub_state_changes(ohci, changed,
any_connected, rhsc_status))
set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
else
clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
done:
spin_unlock_irqrestore (&ohci->lock, flags);
return changed ? length : 0;
}
EXPORT_SYMBOL_GPL(ohci_hub_status_data);
/*-------------------------------------------------------------------------*/
static void
ohci_hub_descriptor (
struct ohci_hcd *ohci,
struct usb_hub_descriptor *desc
) {
u32 rh = roothub_a (ohci);
u16 temp;
desc->bDescriptorType = USB_DT_HUB;
desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
desc->bHubContrCurrent = 0;
desc->bNbrPorts = ohci->num_ports;
temp = 1 + (ohci->num_ports / 8);
desc->bDescLength = 7 + 2 * temp;
temp = HUB_CHAR_COMMON_LPSM | HUB_CHAR_COMMON_OCPM;
if (rh & RH_A_NPS) /* no power switching? */
temp |= HUB_CHAR_NO_LPSM;
if (rh & RH_A_PSM) /* per-port power switching? */
temp |= HUB_CHAR_INDV_PORT_LPSM;
if (rh & RH_A_NOCP) /* no overcurrent reporting? */
temp |= HUB_CHAR_NO_OCPM;
else if (rh & RH_A_OCPM) /* per-port overcurrent reporting? */
temp |= HUB_CHAR_INDV_PORT_OCPM;
desc->wHubCharacteristics = cpu_to_le16(temp);
/* ports removable, and usb 1.0 legacy PortPwrCtrlMask */
rh = roothub_b (ohci);
memset(desc->u.hs.DeviceRemovable, 0xff,
sizeof(desc->u.hs.DeviceRemovable));
desc->u.hs.DeviceRemovable[0] = rh & RH_B_DR;
if (ohci->num_ports > 7) {
desc->u.hs.DeviceRemovable[1] = (rh & RH_B_DR) >> 8;
desc->u.hs.DeviceRemovable[2] = 0xff;
} else
desc->u.hs.DeviceRemovable[1] = 0xff;
}
/*-------------------------------------------------------------------------*/
#ifdef CONFIG_USB_OTG
static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
u32 status;
if (!port)
return -EINVAL;
port--;
/* start port reset before HNP protocol times out */
status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
if (!(status & RH_PS_CCS))
return -ENODEV;
/* hub_wq will finish the reset later */
ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
return 0;
}
#else
#define ohci_start_port_reset NULL
#endif
/*-------------------------------------------------------------------------*/
/* See usb 7.1.7.5: root hubs must issue at least 50 msec reset signaling,
* not necessarily continuous ... to guard against resume signaling.
*/
#define PORT_RESET_MSEC 50
/* this timer value might be vendor-specific ... */
#define PORT_RESET_HW_MSEC 10
/* wrap-aware logic morphed from <linux/jiffies.h> */
#define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)
/* called from some task, normally hub_wq */
static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
{
__hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
u32 temp = 0;
u16 now = ohci_readl(ohci, &ohci->regs->fmnumber);
u16 reset_done = now + PORT_RESET_MSEC;
int limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);
/* build a "continuous enough" reset signal, with up to
* 3msec gap between pulses. scheduler HZ==100 must work;
* this might need to be deadline-scheduled.
*/
do {
int limit_2;
/* spin until any current reset finishes */
limit_2 = PORT_RESET_HW_MSEC * 2;
while (--limit_2 >= 0) {
temp = ohci_readl (ohci, portstat);
/* handle e.g. CardBus eject */
if (temp == ~(u32)0)
return -ESHUTDOWN;
if (!(temp & RH_PS_PRS))
break;
udelay (500);
}
/* timeout (a hardware error) has been observed when
* EHCI sets CF while this driver is resetting a port;
* presumably other disconnect paths might do it too.
*/
if (limit_2 < 0) {
ohci_dbg(ohci,
"port[%d] reset timeout, stat %08x\n",
port, temp);
break;
}
if (!(temp & RH_PS_CCS))
break;
if (temp & RH_PS_PRSC)
ohci_writel (ohci, RH_PS_PRSC, portstat);
/* start the next reset, sleep till it's probably done */
ohci_writel (ohci, RH_PS_PRS, portstat);
msleep(PORT_RESET_HW_MSEC);
now = ohci_readl(ohci, &ohci->regs->fmnumber);
} while (tick_before(now, reset_done) && --limit_1 >= 0);
/* caller synchronizes using PRSC ... and handles PRS
* still being set when this returns.
*/
return 0;
}
int ohci_hub_control(
struct usb_hcd *hcd,
u16 typeReq,
u16 wValue,
u16 wIndex,
char *buf,
u16 wLength
) {
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int ports = ohci->num_ports;
u32 temp;
int retval = 0;
if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
return -ESHUTDOWN;
switch (typeReq) {
case ClearHubFeature:
switch (wValue) {
case C_HUB_OVER_CURRENT:
ohci_writel (ohci, RH_HS_OCIC,
&ohci->regs->roothub.status);
case C_HUB_LOCAL_POWER:
break;
default:
goto error;
}
break;
case ClearPortFeature:
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
switch (wValue) {
case USB_PORT_FEAT_ENABLE:
temp = RH_PS_CCS;
break;
case USB_PORT_FEAT_C_ENABLE:
temp = RH_PS_PESC;
break;
case USB_PORT_FEAT_SUSPEND:
temp = RH_PS_POCI;
break;
case USB_PORT_FEAT_C_SUSPEND:
temp = RH_PS_PSSC;
break;
case USB_PORT_FEAT_POWER:
temp = RH_PS_LSDA;
break;
case USB_PORT_FEAT_C_CONNECTION:
temp = RH_PS_CSC;
break;
case USB_PORT_FEAT_C_OVER_CURRENT:
temp = RH_PS_OCIC;
break;
case USB_PORT_FEAT_C_RESET:
temp = RH_PS_PRSC;
break;
default:
goto error;
}
ohci_writel (ohci, temp,
&ohci->regs->roothub.portstatus [wIndex]);
// ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
break;
case GetHubDescriptor:
ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
break;
case GetHubStatus:
temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
put_unaligned_le32(temp, buf);
break;
case GetPortStatus:
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
temp = roothub_portstatus (ohci, wIndex);
put_unaligned_le32(temp, buf);
if (*(u16*)(buf+2)) /* only if wPortChange is interesting */
dbg_port(ohci, "GetStatus", wIndex, temp);
break;
case SetHubFeature:
switch (wValue) {
case C_HUB_OVER_CURRENT:
// FIXME: this can be cleared, yes?
case C_HUB_LOCAL_POWER:
break;
default:
goto error;
}
break;
case SetPortFeature:
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
switch (wValue) {
case USB_PORT_FEAT_SUSPEND:
#ifdef CONFIG_USB_OTG
if (hcd->self.otg_port == (wIndex + 1)
&& hcd->self.b_hnp_enable)
ohci->start_hnp(ohci);
else
#endif
ohci_writel (ohci, RH_PS_PSS,
&ohci->regs->roothub.portstatus [wIndex]);
break;
case USB_PORT_FEAT_POWER:
ohci_writel (ohci, RH_PS_PPS,
&ohci->regs->roothub.portstatus [wIndex]);
break;
case USB_PORT_FEAT_RESET:
retval = root_port_reset (ohci, wIndex);
break;
default:
goto error;
}
break;
default:
error:
/* "protocol stall" on error */
retval = -EPIPE;
}
return retval;
}
EXPORT_SYMBOL_GPL(ohci_hub_control);
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