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Subject[PATCH 07/10] ehci-dbgp,ehci: Allow early or late use of the dbgp device
Date
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 debug port was moved from the ehci_pci_reinit()
to the EHCI host controller reset logic because it applies to any
condition where EHCI host controller is getting reset.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Cc: Greg KH <gregkh@suse.de>
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>
---
drivers/usb/early/ehci-dbgp.c | 23 +++++++++++++++++++++++
drivers/usb/host/ehci-hcd.c | 33 ++++++++++++++++++++++++++++++++-
drivers/usb/host/ehci-hub.c | 10 ++++++++++
drivers/usb/host/ehci-pci.c | 20 --------------------
include/linux/usb/ehci_def.h | 1 +
5 files changed, 66 insertions(+), 21 deletions(-)
diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c
index 06e05ea..b88cb65 100644
--- 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 7d03549..0d9cf9d 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -238,7 +238,33 @@ static int ehci_reset (struct ehci_hcd *ehci)
{
int retval;
u32 command = ehci_readl(ehci, &ehci->regs->command);
-
+ u32 temp;
+ struct pci_dev *pdev = to_pci_dev(ehci_to_hcd(ehci)->self.controller);
+
+ /* Special handling for the ehci debug port */
+ ehci->debug = NULL;
+ /* 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 &= 0xfff;
+ 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"
+ : "");
+#ifdef CONFIG_EARLY_PRINTK_DBGP
+ if (!dbgp_reset_prep() || !(temp & DBGP_ENABLED))
+#else
+ if (!(temp & DBGP_ENABLED))
+#endif
+ ehci->debug = NULL;
+ }
+ }
command |= CMD_RESET;
dbg_cmd (ehci, "reset", command);
ehci_writel(ehci, command, &ehci->regs->command);
@@ -253,6 +279,11 @@ static int ehci_reset (struct ehci_hcd *ehci)
if (ehci_is_TDI(ehci))
tdi_reset (ehci);

+#ifdef CONFIG_EARLY_PRINTK_DBGP
+ /* Restore debug facilities if the controler was active */
+ if (ehci->debug)
+ dbgp_external_startup();
+#endif
return retval;
}

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index f46ad27..149beb8 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -816,6 +816,15 @@ 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 ((readl(&ehci->debug->control) & DBGP_ENABLED) &&
+ wIndex == HCS_DEBUG_PORT(ehci->hcs_params)) {
+ retval = -ENODEV;
+ goto error_exit;
+ }
+ }
if (!wIndex || wIndex > ports)
goto error;
wIndex--;
@@ -894,6 +903,7 @@ 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 c2f1b7d..af73d12 100644
--- 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
*/
diff --git a/include/linux/usb/ehci_def.h b/include/linux/usb/ehci_def.h
index e1346fd..279d48b 100644
--- a/include/linux/usb/ehci_def.h
+++ b/include/linux/usb/ehci_def.h
@@ -166,6 +166,7 @@ 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);
#endif

#endif /* __LINUX_USB_EHCI_DEF_H */
--
1.6.0.3.523.g304d0


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