USB: ehci-dbgp,ehci: Allow early or late use of the dbgp device

If the EHCI debug port is initialized and in use, the EHCI host
controller driver must follow two rules.

1) If the EHCI host driver issues a controller reset, the debug
   controller driver re-initialization must get called after the reset
   is completed.

2) The EHCI host driver should ignore any requests to the physical
   EHCI debug port when the EHCI debug port is in use.

The code to check for the debug port was moved from ehci_pci_reinit()
to ehci_pci_setup because it must get called prior to ehci_reset()
which will clear the debug port registers.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: dbrownell@users.sourceforge.net
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c
index 06e05ea178712bb5957bb8ae00077445ffeddebc..b88cb65b64e031d2c854555ab678be15e878042c 100644 (file)
--- a/drivers/usb/early/ehci-dbgp.c
+++ b/drivers/usb/early/ehci-dbgp.c
@@ -933,3 +933,26 @@ struct console early_dbgp_console = {
        .flags =        CON_PRINTBUFFER,
        .index =        -1,
 };
+
+int dbgp_reset_prep(void)
+{
+       u32 ctrl;
+
+       dbgp_not_safe = 1;
+       if (!ehci_debug)
+               return 0;
+
+       if (early_dbgp_console.index != -1 &&
+               !(early_dbgp_console.flags & CON_BOOT))
+               return 1;
+       /* This means the console is not initialized, or should get
+        * shutdown so as to allow for reuse of the usb device, which
+        * means it is time to shutdown the usb debug port. */
+       ctrl = readl(&ehci_debug->control);
+       if (ctrl & DBGP_ENABLED) {
+               ctrl &= ~(DBGP_CLAIM);
+               writel(ctrl, &ehci_debug->control);
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(dbgp_reset_prep);

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 4f89d7ffd53a23130307ceb7d4af0e27e8c726be..9835e0713943397fde9b5200f58fa36ab7db547a 100644 (file)
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -240,6 +240,11 @@ static int ehci_reset (struct ehci_hcd *ehci)
        int     retval;
        u32     command = ehci_readl(ehci, &ehci->regs->command);
 
+       /* If the EHCI debug controller is active, special care must be
+        * taken before and after a host controller reset */
+       if (ehci->debug && !dbgp_reset_prep())
+               ehci->debug = NULL;
+
        command |= CMD_RESET;
        dbg_cmd (ehci, "reset", command);
        ehci_writel(ehci, command, &ehci->regs->command);
@@ -260,6 +265,9 @@ static int ehci_reset (struct ehci_hcd *ehci)
        if (ehci_is_TDI(ehci))
                tdi_reset (ehci);
 
+       if (ehci->debug)
+               dbgp_external_startup();
+
        return retval;
 }
 

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 818647c33da889eced7bb700bb3ba7500f4f2030..6b5e4d18d4bf047acfbdbd06b5b306c49a13a2c2 100644 (file)
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -855,6 +855,15 @@ static int ehci_hub_control (
        case SetPortFeature:
                selector = wIndex >> 8;
                wIndex &= 0xff;
+               if (unlikely(ehci->debug)) {
+                       /* If the debug port is active any port
+                        * feature requests should get denied */
+                       if (wIndex == HCS_DEBUG_PORT(ehci->hcs_params) &&
+                           (readl(&ehci->debug->control) & DBGP_ENABLED)) {
+                               retval = -ENODEV;
+                               goto error_exit;
+                       }
+               }
                if (!wIndex || wIndex > ports)
                        goto error;
                wIndex--;
@@ -951,6 +960,7 @@ error:
                /* "stall" on error */
                retval = -EPIPE;
        }
+error_exit:
        spin_unlock_irqrestore (&ehci->lock, flags);
        return retval;
 }

diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index a88ad517ec5c29c31a397e5e900ae55e8393f789..378861b9d79a96fe926dcf86755c984646528a22 100644 (file)
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -27,28 +27,8 @@
 /* called after powerup, by probe or system-pm "wakeup" */
 static int ehci_pci_reinit(struct ehci_hcd *ehci, struct pci_dev *pdev)
 {
-       u32                     temp;
        int                     retval;
 
-       /* optional debug port, normally in the first BAR */
-       temp = pci_find_capability(pdev, 0x0a);
-       if (temp) {
-               pci_read_config_dword(pdev, temp, &temp);
-               temp >>= 16;
-               if ((temp & (3 << 13)) == (1 << 13)) {
-                       temp &= 0x1fff;
-                       ehci->debug = ehci_to_hcd(ehci)->regs + temp;
-                       temp = ehci_readl(ehci, &ehci->debug->control);
-                       ehci_info(ehci, "debug port %d%s\n",
-                               HCS_DEBUG_PORT(ehci->hcs_params),
-                               (temp & DBGP_ENABLED)
-                                       ? " IN USE"
-                                       : "");
-                       if (!(temp & DBGP_ENABLED))
-                               ehci->debug = NULL;
-               }
-       }
-
        /* we expect static quirk code to handle the "extended capabilities"
         * (currently just BIOS handoff) allowed starting with EHCI 0.96
         */
@@ -195,6 +175,25 @@ static int ehci_pci_setup(struct usb_hcd *hcd)
                break;
        }
 
+       /* optional debug port, normally in the first BAR */
+       temp = pci_find_capability(pdev, 0x0a);
+       if (temp) {
+               pci_read_config_dword(pdev, temp, &temp);
+               temp >>= 16;
+               if ((temp & (3 << 13)) == (1 << 13)) {
+                       temp &= 0x1fff;
+                       ehci->debug = ehci_to_hcd(ehci)->regs + temp;
+                       temp = ehci_readl(ehci, &ehci->debug->control);
+                       ehci_info(ehci, "debug port %d%s\n",
+                               HCS_DEBUG_PORT(ehci->hcs_params),
+                               (temp & DBGP_ENABLED)
+                                       ? " IN USE"
+                                       : "");
+                       if (!(temp & DBGP_ENABLED))
+                               ehci->debug = NULL;
+               }
+       }
+
        ehci_reset(ehci);
 
        /* at least the Genesys GL880S needs fixup here */

diff --git a/include/linux/usb/ehci_def.h b/include/linux/usb/ehci_def.h
index 07851e05d76371cb53d3aa6cd65f1106f11ba850..1909d924f8162ea9a85b2473754ec511a6e7977c 100644 (file)
--- a/include/linux/usb/ehci_def.h
+++ b/include/linux/usb/ehci_def.h
@@ -179,6 +179,16 @@ extern struct console early_dbgp_console;
 #ifdef CONFIG_EARLY_PRINTK_DBGP
 /* Call backs from ehci host driver to ehci debug driver */
 extern int dbgp_external_startup(void);
+extern int dbgp_reset_prep(void);
+#else
+static inline int dbgp_reset_prep(void)
+{
+       return 1;
+}
+static inline int dbgp_external_startup(void)
+{
+       return -1;
+}
 #endif
 
 #endif /* __LINUX_USB_EHCI_DEF_H */