From 57e06c11372eccf5acebdd4664eb025fee76c561 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 16 Jan 2007 11:59:45 -0500 Subject: [PATCH] EHCI: force high-speed devices to run at full speed This patch (as710) adds a sysfs class-device attribute file named "companion" for EHCI controllers. The file contains a list of port numbers that are dedicated to the companion controller; by writing a port number to the file the user can force a high-speed device attached directly to the computer to run at full speed. (As far as I know it is not possible to do this for a device attached to an external hub.) A port is removed from the file by writing the negative of its port number. Several users have asked for this facility and it seems like a useful thing to have. Every now and then one runs across a device which behaves much better at full speed than at high speed. Signed-off-by: Alan Stern Cc: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 2 + drivers/usb/host/ehci-hub.c | 107 ++++++++++++++++++++++++++++++++++++ drivers/usb/host/ehci.h | 6 +- 3 files changed, 114 insertions(+), 1 deletion(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 9ec896218fe..92c62911f57 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -388,6 +388,7 @@ static void ehci_stop (struct usb_hcd *hcd) /* let companion controllers work when we aren't */ ehci_writel(ehci, 0, &ehci->regs->configured_flag); + remove_companion_file(ehci); remove_debug_files (ehci); /* root hub is shut down separately (first, when possible) */ @@ -563,6 +564,7 @@ static int ehci_run (struct usb_hcd *hcd) * since the class device isn't created that early. */ create_debug_files(ehci); + create_companion_file(ehci); return 0; } diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index 076474d95db..3cfba69e076 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -188,6 +188,103 @@ static int ehci_bus_resume (struct usb_hcd *hcd) #endif /* CONFIG_PM */ +/*-------------------------------------------------------------------------*/ + +/* Display the ports dedicated to the companion controller */ +static ssize_t show_companion(struct class_device *class_dev, char *buf) +{ + struct ehci_hcd *ehci; + int nports, index, n; + int count = PAGE_SIZE; + char *ptr = buf; + + ehci = hcd_to_ehci(bus_to_hcd(class_get_devdata(class_dev))); + nports = HCS_N_PORTS(ehci->hcs_params); + + for (index = 0; index < nports; ++index) { + if (test_bit(index, &ehci->companion_ports)) { + n = scnprintf(ptr, count, "%d\n", index + 1); + ptr += n; + count -= n; + } + } + return ptr - buf; +} + +/* + * Dedicate or undedicate a port to the companion controller. + * Syntax is "[-]portnum", where a leading '-' sign means + * return control of the port to the EHCI controller. + */ +static ssize_t store_companion(struct class_device *class_dev, + const char *buf, size_t count) +{ + struct ehci_hcd *ehci; + int portnum, new_owner, try; + u32 __iomem *status_reg; + u32 port_status; + + ehci = hcd_to_ehci(bus_to_hcd(class_get_devdata(class_dev))); + new_owner = PORT_OWNER; /* Owned by companion */ + if (sscanf(buf, "%d", &portnum) != 1) + return -EINVAL; + if (portnum < 0) { + portnum = - portnum; + new_owner = 0; /* Owned by EHCI */ + } + if (portnum <= 0 || portnum > HCS_N_PORTS(ehci->hcs_params)) + return -ENOENT; + status_reg = &ehci->regs->port_status[--portnum]; + if (new_owner) + set_bit(portnum, &ehci->companion_ports); + else + clear_bit(portnum, &ehci->companion_ports); + + /* + * The controller won't set the OWNER bit if the port is + * enabled, so this loop will sometimes require at least two + * iterations: one to disable the port and one to set OWNER. + */ + + for (try = 4; try > 0; --try) { + spin_lock_irq(&ehci->lock); + port_status = ehci_readl(ehci, status_reg); + if ((port_status & PORT_OWNER) == new_owner + || (port_status & (PORT_OWNER | PORT_CONNECT)) + == 0) + try = 0; + else { + port_status ^= PORT_OWNER; + port_status &= ~(PORT_PE | PORT_RWC_BITS); + ehci_writel(ehci, port_status, status_reg); + } + spin_unlock_irq(&ehci->lock); + if (try > 1) + msleep(5); + } + return count; +} +static CLASS_DEVICE_ATTR(companion, 0644, show_companion, store_companion); + +static inline void create_companion_file(struct ehci_hcd *ehci) +{ + int i; + + /* with integrated TT there is no companion! */ + if (!ehci_is_TDI(ehci)) + i = class_device_create_file(ehci_to_hcd(ehci)->self.class_dev, + &class_device_attr_companion); +} + +static inline void remove_companion_file(struct ehci_hcd *ehci) +{ + /* with integrated TT there is no companion! */ + if (!ehci_is_TDI(ehci)) + class_device_remove_file(ehci_to_hcd(ehci)->self.class_dev, + &class_device_attr_companion); +} + + /*-------------------------------------------------------------------------*/ static int check_reset_complete ( @@ -504,6 +601,16 @@ static int ehci_hub_control ( ehci_readl(ehci, status_reg)); } + /* transfer dedicated ports to the companion hc */ + if ((temp & PORT_CONNECT) && + test_bit(wIndex, &ehci->companion_ports)) { + temp &= ~PORT_RWC_BITS; + temp |= PORT_OWNER; + ehci_writel(ehci, temp, status_reg); + ehci_dbg(ehci, "port %d --> companion\n", wIndex + 1); + temp = ehci_readl(ehci, status_reg); + } + /* * Even if OWNER is set, there's no harm letting khubd * see the wPortStatus values (they should all be 0 except diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index 3ce7249085d..ec0da0343be 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -74,7 +74,11 @@ struct ehci_hcd { /* one per controller */ /* per root hub port */ unsigned long reset_done [EHCI_MAX_ROOT_PORTS]; - unsigned long bus_suspended; + /* 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 */ /* per-HC memory pools (could be per-bus, but ...) */ struct dma_pool *qh_pool; /* qh per active urb */ -- 2.41.1