From 383975d765523a56dc43a6cd6d52e9b376800cf2 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 4 May 2007 11:52:40 -0400 Subject: [PATCH] USB: EHCI, OHCI: handover changes This patch (as887) changes the way ehci-hcd and ohci-hcd handle a loss of VBUS power during suspend. In order for the USB-persist facility to work correctly, it is necessary for low- and full-speed devices attached to a high-speed port to be handed back to the companion controller during resume processing. This entails three changes: adding code to ehci-hcd to perform the handover, removing code from ohci-hcd to turn off ports during root-hub reinit, and adding code to ohci-hcd to turn on ports during PCI controller resume. (Other bus glue resume methods for platforms supporting high-speed controllers would need a similar change, if any existed.) Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 2 + drivers/usb/host/ehci-hub.c | 99 +++++++++++++++++++++++++++++++++++-- drivers/usb/host/ehci-pci.c | 7 +-- drivers/usb/host/ehci.h | 3 ++ drivers/usb/host/ohci-hcd.c | 21 +------- drivers/usb/host/ohci-pci.c | 41 ++++++++++++++- 6 files changed, 145 insertions(+), 28 deletions(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 99ab31e977..b5a7aa9020 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -399,6 +399,8 @@ static void ehci_port_power (struct ehci_hcd *ehci, int is_on) is_on ? SetPortFeature : ClearPortFeature, USB_PORT_FEAT_POWER, port--, NULL, 0); + /* Flush those writes */ + ehci_readl(ehci, &ehci->regs->command); msleep(20); } diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index f4d301bc83..3e80de7c7f 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -28,6 +28,87 @@ /*-------------------------------------------------------------------------*/ +#ifdef CONFIG_USB_PERSIST + +static int ehci_hub_control( + struct usb_hcd *hcd, + u16 typeReq, + u16 wValue, + u16 wIndex, + char *buf, + u16 wLength +); + +/* After a power loss, ports that were owned by the companion must be + * reset so that the companion can still own them. + */ +static void ehci_handover_companion_ports(struct ehci_hcd *ehci) +{ + u32 __iomem *reg; + u32 status; + int port; + __le32 buf; + struct usb_hcd *hcd = ehci_to_hcd(ehci); + + if (!ehci->owned_ports) + return; + + /* Give the connections some time to appear */ + msleep(20); + + port = HCS_N_PORTS(ehci->hcs_params); + while (port--) { + if (test_bit(port, &ehci->owned_ports)) { + reg = &ehci->regs->port_status[port]; + status = ehci_readl(ehci, reg); + + /* Port already owned by companion? */ + if (status & PORT_OWNER) + clear_bit(port, &ehci->owned_ports); + else + ehci_hub_control(hcd, SetPortFeature, + USB_PORT_FEAT_RESET, port + 1, + NULL, 0); + } + } + + if (!ehci->owned_ports) + return; + msleep(90); /* Wait for resets to complete */ + + port = HCS_N_PORTS(ehci->hcs_params); + while (port--) { + if (test_bit(port, &ehci->owned_ports)) { + ehci_hub_control(hcd, GetPortStatus, + 0, port + 1, + (char *) &buf, sizeof(buf)); + + /* The companion should now own the port, + * but if something went wrong the port must not + * remain enabled. + */ + reg = &ehci->regs->port_status[port]; + status = ehci_readl(ehci, reg) & ~PORT_RWC_BITS; + if (status & PORT_OWNER) + ehci_writel(ehci, status | PORT_CSC, reg); + else { + ehci_dbg(ehci, "failed handover port %d: %x\n", + port + 1, status); + ehci_writel(ehci, status & ~PORT_PE, reg); + } + } + } + + ehci->owned_ports = 0; +} + +#else /* CONFIG_USB_PERSIST */ + +static inline void ehci_handover_companion_ports(struct ehci_hcd *ehci) +{ } + +#endif + #ifdef CONFIG_PM static int ehci_bus_suspend (struct usb_hcd *hcd) @@ -60,14 +141,16 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) * then manually resume them in the bus_resume() routine. */ ehci->bus_suspended = 0; + ehci->owned_ports = 0; while (port--) { u32 __iomem *reg = &ehci->regs->port_status [port]; u32 t1 = ehci_readl(ehci, reg) & ~PORT_RWC_BITS; u32 t2 = t1; /* keep track of which ports we suspend */ - if ((t1 & PORT_PE) && !(t1 & PORT_OWNER) && - !(t1 & PORT_SUSPEND)) { + if (t1 & PORT_OWNER) + set_bit(port, &ehci->owned_ports); + else if ((t1 & PORT_PE) && !(t1 & PORT_SUSPEND)) { t2 |= PORT_SUSPEND; set_bit(port, &ehci->bus_suspended); } @@ -108,6 +191,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd) { struct ehci_hcd *ehci = hcd_to_ehci (hcd); u32 temp; + u32 power_okay; int i; if (time_before (jiffies, ehci->next_statechange)) @@ -120,8 +204,9 @@ static int ehci_bus_resume (struct usb_hcd *hcd) * the last user of the controller, not reset/pm hardware keeping * state we gave to it. */ - temp = ehci_readl(ehci, &ehci->regs->intr_enable); - ehci_dbg(ehci, "resume root hub%s\n", temp ? "" : " after power loss"); + power_okay = ehci_readl(ehci, &ehci->regs->intr_enable); + ehci_dbg(ehci, "resume root hub%s\n", + power_okay ? "" : " after power loss"); /* at least some APM implementations will try to deliver * IRQs right away, so delay them until we're ready. @@ -184,6 +269,9 @@ static int ehci_bus_resume (struct usb_hcd *hcd) ehci_writel(ehci, INTR_MASK, &ehci->regs->intr_enable); spin_unlock_irq (&ehci->lock); + + if (!power_okay) + ehci_handover_companion_ports(ehci); return 0; } @@ -448,7 +536,8 @@ static int ehci_hub_control ( ) { struct ehci_hcd *ehci = hcd_to_ehci (hcd); int ports = HCS_N_PORTS (ehci->hcs_params); - u32 __iomem *status_reg = &ehci->regs->port_status[wIndex - 1]; + u32 __iomem *status_reg = &ehci->regs->port_status[ + (wIndex & 0xff) - 1]; u32 temp, status; unsigned long flags; int retval = 0; diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c index 966965f723..a7816e392a 100644 --- a/drivers/usb/host/ehci-pci.c +++ b/drivers/usb/host/ehci-pci.c @@ -312,13 +312,14 @@ static int ehci_pci_resume(struct usb_hcd *hcd) ehci_work(ehci); spin_unlock_irq(&ehci->lock); - /* here we "know" root ports should always stay powered */ - ehci_port_power(ehci, 1); - ehci_writel(ehci, ehci->command, &ehci->regs->command); ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag); ehci_readl(ehci, &ehci->regs->command); /* unblock posted writes */ + /* here we "know" root ports should always stay powered */ + ehci_port_power(ehci, 1); + ehci_handover_companion_ports(ehci); + hcd->state = HC_STATE_SUSPENDED; return 0; } diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 6ef9d77577..4d617108f5 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -96,11 +96,14 @@ struct ehci_hcd { /* one per controller */ /* per root hub port */ unsigned long reset_done [EHCI_MAX_ROOT_PORTS]; + /* bit vectors (one bit per port) */ unsigned long bus_suspended; /* which ports were already suspended at the start of a bus suspend */ unsigned long companion_ports; /* which ports are dedicated to the companion controller */ + unsigned long owned_ports; /* which ports are + owned by the companion during a bus suspend */ /* per-HC memory pools (could be per-bus, but ...) */ struct dma_pool *qh_pool; /* qh per active urb */ diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c index a66637e725..ce05e5f7be 100644 --- a/drivers/usb/host/ohci-hcd.c +++ b/drivers/usb/host/ohci-hcd.c @@ -510,15 +510,7 @@ static int ohci_run (struct ohci_hcd *ohci) // flush the writes (void) ohci_readl (ohci, &ohci->regs->control); msleep(temp); - temp = roothub_a (ohci); - if (!(temp & RH_A_NPS)) { - /* power down each port */ - for (temp = 0; temp < ohci->num_ports; temp++) - ohci_writel (ohci, RH_PS_LSDA, - &ohci->regs->roothub.portstatus [temp]); - } - // flush those writes - (void) ohci_readl (ohci, &ohci->regs->control); + memset (ohci->hcca, 0, sizeof (struct ohci_hcca)); /* 2msec timelimit here means no irqs/preempt */ @@ -826,17 +818,8 @@ static int ohci_restart (struct ohci_hcd *ohci) if ((temp = ohci_run (ohci)) < 0) { ohci_err (ohci, "can't restart, %d\n", temp); return temp; - } else { - /* here we "know" root ports should always stay powered, - * and that if we try to turn them back on the root hub - * will respond to CSC processing. - */ - i = ohci->num_ports; - while (i--) - ohci_writel (ohci, RH_PS_PSS, - &ohci->regs->roothub.portstatus [i]); - ohci_dbg (ohci, "restart complete\n"); } + ohci_dbg(ohci, "restart complete\n"); return 0; } #endif diff --git a/drivers/usb/host/ohci-pci.c b/drivers/usb/host/ohci-pci.c index ca62cb5832..15013f4519 100644 --- a/drivers/usb/host/ohci-pci.c +++ b/drivers/usb/host/ohci-pci.c @@ -202,6 +202,42 @@ static int __devinit ohci_pci_start (struct usb_hcd *hcd) return ret; } +#if defined(CONFIG_USB_PERSIST) && (defined(CONFIG_USB_EHCI_HCD) || \ + defined(CONFIG_USB_EHCI_HCD_MODULE)) + +/* Following a power loss, we must prepare to regain control of the ports + * we used to own. This means turning on the port power before ehci-hcd + * tries to switch ownership. + * + * This isn't a 100% perfect solution. On most systems the OHCI controllers + * lie at lower PCI addresses than the EHCI controller, so they will be + * discovered (and hence resumed) first. But there is no guarantee things + * will always work this way. If the EHCI controller is resumed first and + * the OHCI ports are unpowered, then the handover will fail. + */ +static void prepare_for_handover(struct usb_hcd *hcd) +{ + struct ohci_hcd *ohci = hcd_to_ohci(hcd); + int port; + + /* Here we "know" root ports should always stay powered */ + ohci_dbg(ohci, "powerup ports\n"); + for (port = 0; port < ohci->num_ports; port++) + ohci_writel(ohci, RH_PS_PPS, + &ohci->regs->roothub.portstatus[port]); + + /* Flush those writes */ + ohci_readl(ohci, &ohci->regs->control); + msleep(20); +} + +#else + +static inline void prepare_for_handover(struct usb_hcd *hcd) +{ } + +#endif /* CONFIG_USB_PERSIST etc. */ + #ifdef CONFIG_PM static int ohci_pci_suspend (struct usb_hcd *hcd, pm_message_t message) @@ -241,7 +277,10 @@ static int ohci_pci_suspend (struct usb_hcd *hcd, pm_message_t message) static int ohci_pci_resume (struct usb_hcd *hcd) { set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags); - usb_hcd_resume_root_hub(hcd); + + /* FIXME: we should try to detect loss of VBUS power here */ + prepare_for_handover(hcd); + return 0; } -- 2.39.5