This patch (as1537) adds a bit-array to ehci-hcd for keeping track of
which ports are undergoing a resume transition. If any of the bits
are set when ehci_hub_status_data() is called, the routine will return
a nonzero value even if no ports have any status changes pending.
This will allow usbcore to handle races between root-hub suspend and
port wakeup.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
CC: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
CC: Chen Peter-B29397 <B29397@xxxxxxxxxxxxx>
CC: <stable@xxxxxxxxxxxxxxx>
---
drivers/usb/host/ehci-hcd.c | 3 +++
drivers/usb/host/ehci-hub.c | 31 ++++++++++++++++---------------
drivers/usb/host/ehci-tegra.c | 2 ++
drivers/usb/host/ehci.h | 2 ++
4 files changed, 23 insertions(+), 15 deletions(-)
Index: usb-3.3/drivers/usb/host/ehci.h
===================================================================
--- usb-3.3.orig/drivers/usb/host/ehci.h
+++ usb-3.3/drivers/usb/host/ehci.h
@@ -117,6 +117,8 @@ struct ehci_hcd { /* one per controlle
the change-suspend feature turned on */
unsigned long suspended_ports; /* which ports are
suspended */
+ unsigned long resuming_ports; /* which ports have
+ started to resume */
/* per-HC memory pools (could be per-bus, but ...) */
struct dma_pool *qh_pool; /* qh per active urb */
Index: usb-3.3/drivers/usb/host/ehci-hub.c
===================================================================
--- usb-3.3.orig/drivers/usb/host/ehci-hub.c
+++ usb-3.3/drivers/usb/host/ehci-hub.c
@@ -223,15 +223,10 @@ static int ehci_bus_suspend (struct usb_
* remote wakeup, we must fail the suspend.
*/
if (hcd->self.root_hub->do_remote_wakeup) {
- port = HCS_N_PORTS(ehci->hcs_params);
- while (port--) {
- if (ehci->reset_done[port] != 0) {
- spin_unlock_irq(&ehci->lock);
- ehci_dbg(ehci, "suspend failed because "
- "port %d is resuming\n",
- port + 1);
- return -EBUSY;
- }
+ if (ehci->resuming_ports) {
+ spin_unlock_irq(&ehci->lock);
+ ehci_dbg(ehci, "suspend failed because a port is resuming\n");
+ return -EBUSY;
}
}
@@ -554,16 +549,12 @@ static int
ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
{
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
- u32 temp, status = 0;
+ u32 temp, status;
u32 mask;
int ports, i, retval = 1;
unsigned long flags;
u32 ppcd = 0;
- /* if !USB_SUSPEND, root hub timers won't get shut down ... */
- if (ehci->rh_state != EHCI_RH_RUNNING)
- return 0;
-
/* init status to no-changes */
buf [0] = 0;
ports = HCS_N_PORTS (ehci->hcs_params);
@@ -572,6 +563,11 @@ ehci_hub_status_data (struct usb_hcd *hc
retval++;
}
+ /* Inform the core about resumes-in-progress by returning
+ * a non-zero value even if there are no status changes.
+ */
+ status = ehci->resuming_ports;
+
/* Some boards (mostly VIA?) report bogus overcurrent indications,
* causing massive log spam unless we completely ignore them. It
* may be relevant that VIA VT8235 controllers, where PORT_POWER is
@@ -846,6 +842,7 @@ static int ehci_hub_control (
ehci_writel(ehci,
temp & ~(PORT_RWC_BITS | PORT_RESUME),
status_reg);
+ clear_bit(wIndex, &ehci->resuming_ports);
retval = handshake(ehci, status_reg,
PORT_RESUME, 0, 2000 /* 2msec */);
if (retval != 0) {
@@ -864,6 +861,7 @@ static int ehci_hub_control (
ehci->reset_done[wIndex])) {
status |= USB_PORT_STAT_C_RESET << 16;
ehci->reset_done [wIndex] = 0;
+ clear_bit(wIndex, &ehci->resuming_ports);
/* force reset to complete */
ehci_writel(ehci, temp & ~(PORT_RWC_BITS | PORT_RESET),
@@ -884,8 +882,10 @@ static int ehci_hub_control (
ehci_readl(ehci, status_reg));
}
- if (!(temp & (PORT_RESUME|PORT_RESET)))
+ if (!(temp & (PORT_RESUME|PORT_RESET))) {
ehci->reset_done[wIndex] = 0;
+ clear_bit(wIndex, &ehci->resuming_ports);
+ }
/* transfer dedicated ports to the companion hc */
if ((temp & PORT_CONNECT) &&
@@ -920,6 +920,7 @@ static int ehci_hub_control (
status |= USB_PORT_STAT_SUSPEND;
} else if (test_bit(wIndex, &ehci->suspended_ports)) {
clear_bit(wIndex, &ehci->suspended_ports);
+ clear_bit(wIndex, &ehci->resuming_ports);
ehci->reset_done[wIndex] = 0;
if (temp & PORT_PE)
set_bit(wIndex, &ehci->port_c_suspend);
Index: usb-3.3/drivers/usb/host/ehci-hcd.c
===================================================================
--- usb-3.3.orig/drivers/usb/host/ehci-hcd.c
+++ usb-3.3/drivers/usb/host/ehci-hcd.c
@@ -347,6 +347,8 @@ static int ehci_reset (struct ehci_hcd *
if (ehci->debug)
dbgp_external_startup();
+ ehci->port_c_suspend = ehci->suspended_ports =
+ ehci->resuming_ports = 0;
return retval;
}
@@ -939,6 +941,7 @@ static irqreturn_t ehci_irq (struct usb_
* like usb_port_resume() does.
*/
ehci->reset_done[i] = jiffies + msecs_to_jiffies(25);
+ set_bit(i, &ehci->resuming_ports);
ehci_dbg (ehci, "port %d remote wakeup\n", i + 1);
mod_timer(&hcd->rh_timer, ehci->reset_done[i]);
}
Index: usb-3.3/drivers/usb/host/ehci-tegra.c
===================================================================
--- usb-3.3.orig/drivers/usb/host/ehci-tegra.c
+++ usb-3.3/drivers/usb/host/ehci-tegra.c
@@ -224,6 +224,7 @@ static int tegra_ehci_hub_control(
temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
/* start resume signalling */
ehci_writel(ehci, temp | PORT_RESUME, status_reg);
+ set_bit(wIndex-1, &ehci->resuming_ports);
spin_unlock_irqrestore(&ehci->lock, flags);
msleep(20);
@@ -236,6 +237,7 @@ static int tegra_ehci_hub_control(
pr_err("%s: timeout waiting for SUSPEND\n", __func__);
ehci->reset_done[wIndex-1] = 0;
+ clear_bit(wIndex-1, &ehci->resuming_ports);
tegra->port_resuming = 1;
goto done;
--
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