From a448e4dc25303fe551e4dafe16c8c7c34f1b9d82 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 3 Apr 2012 15:24:30 -0400 Subject: [PATCH] EHCI: keep track of ports being resumed and indicate in hub_status_data 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 CC: Sarah Sharp CC: Chen Peter-B29397 Signed-off-by: Greg Kroah-Hartman --- 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(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 057cdda..806cc95 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -347,6 +347,8 @@ static int ehci_reset (struct ehci_hcd *ehci) 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_hcd *hcd) * 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]); } diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index 256fbd4..38fe076 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -223,15 +223,10 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) * 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 *hcd, char *buf) 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); diff --git a/drivers/usb/host/ehci-tegra.c b/drivers/usb/host/ehci-tegra.c index 3de48a2..73544bd 100644 --- a/drivers/usb/host/ehci-tegra.c +++ b/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; diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 8f9acbc..2694ed6 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -117,6 +117,8 @@ struct ehci_hcd { /* one per controller */ 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 */ -- 2.7.4