Re: [linux-usb-devel] [PATCH] Fix NEC OHCI chip silicon bug

From: Michael Hanselmann
Date: Sat Jun 02 2007 - 08:40:36 EST

On Fri, Jun 01, 2007 at 10:19:30AM -0400, Alan Stern wrote:
> > @@ -779,7 +790,11 @@ static int ohci_restart (struct ohci_hcd
> > */
> > spin_lock_irq(&ohci->lock);
> > disable (ohci);
> > +
> > +#ifdef CONFIG_PM
> > usb_root_hub_lost_power(ohci_to_hcd(ohci)->self.root_hub);
> > +#endif
> > +

> Suppose CONFIG_PM isn't defined. How are you going to let usbcore
> know about all the old connections which no longer exist?

You're right, something is wrong there. The patch below uses
usb_root_hub_lost_power again but disables CONFIG_PM specific code in it
when CONFIG_PM isn't defined. It seems to work for me with and without
CONFIG_PM, but I have to confess I might not know enough about Linux'
USB core. Is it better now?

Signed-off-by: Michael Hanselmann <linux-kernel@xxxxxxxxx>

---
diff -Nurp --exclude-from=linux-exclude-from linux-2.6.22-rc3.orig/drivers/usb/core/hub.c linux-2.6.22-rc3/drivers/usb/core/hub.c
--- linux-2.6.22-rc3.orig/drivers/usb/core/hub.c 2007-05-31 22:53:54.000000000 +0200
+++ linux-2.6.22-rc3/drivers/usb/core/hub.c 2007-06-02 14:34:13.000000000 +0200
@@ -1089,9 +1089,6 @@ void usb_set_device_state(struct usb_dev
spin_unlock_irqrestore(&device_state_lock, flags);
}

-
-#ifdef CONFIG_PM
-
/**
* usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
* @rhdev: struct usb_device for the root hub
@@ -1109,10 +1106,12 @@ void usb_root_hub_lost_power(struct usb_

dev_warn(&rhdev->dev, "root hub lost power or was reset\n");

+#ifdef CONFIG_PM
/* Make sure no potential wakeup events get lost,
* by forcing the root hub to be resumed.
*/
rhdev->dev.power.prev_state.event = PM_EVENT_ON;
+#endif /* CONFIG_PM */

spin_lock_irqsave(&device_state_lock, flags);
hub = hdev_to_hub(rhdev);
@@ -1127,8 +1126,6 @@ void usb_root_hub_lost_power(struct usb_
}
EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);

-#endif /* CONFIG_PM */
-
static void choose_address(struct usb_device *udev)
{
int devnum;
diff -Nurp --exclude-from=linux-exclude-from linux-2.6.22-rc3.orig/drivers/usb/host/ohci.h linux-2.6.22-rc3/drivers/usb/host/ohci.h
--- linux-2.6.22-rc3.orig/drivers/usb/host/ohci.h 2007-05-31 22:53:54.000000000 +0200
+++ linux-2.6.22-rc3/drivers/usb/host/ohci.h 2007-05-31 22:54:27.000000000 +0200
@@ -397,8 +397,10 @@ struct ohci_hcd {
#define OHCI_QUIRK_BE_DESC 0x08 /* BE descriptors */
#define OHCI_QUIRK_BE_MMIO 0x10 /* BE registers */
#define OHCI_QUIRK_ZFMICRO 0x20 /* Compaq ZFMicro chipset*/
+#define OHCI_QUIRK_NEC 0x40 /* lost interrupts */
// there are also chip quirks/bugs in init logic

+ struct work_struct nec_work; /* Worker for NEC quirk */
};

/* convert between an hcd pointer and the corresponding ohci_hcd */
diff -Nurp --exclude-from=linux-exclude-from linux-2.6.22-rc3.orig/drivers/usb/host/ohci-hcd.c linux-2.6.22-rc3/drivers/usb/host/ohci-hcd.c
--- linux-2.6.22-rc3.orig/drivers/usb/host/ohci-hcd.c 2007-05-31 22:53:54.000000000 +0200
+++ linux-2.6.22-rc3/drivers/usb/host/ohci-hcd.c 2007-06-02 14:35:18.000000000 +0200
@@ -35,6 +35,7 @@
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/reboot.h>
+#include <linux/workqueue.h>

#include <asm/io.h>
#include <asm/irq.h>
@@ -82,6 +83,8 @@ static const char hcd_name [] = "ohci_hc
static void ohci_dump (struct ohci_hcd *ohci, int verbose);
static int ohci_init (struct ohci_hcd *ohci);
static void ohci_stop (struct usb_hcd *hcd);
+static int ohci_restart (struct ohci_hcd *ohci);
+static void ohci_quirk_nec_worker (struct work_struct *work);

#include "ohci-hub.c"
#include "ohci-dbg.c"
@@ -659,9 +662,20 @@ static irqreturn_t ohci_irq (struct usb_
}

if (ints & OHCI_INTR_UE) {
- disable (ohci);
- ohci_err (ohci, "OHCI Unrecoverable Error, disabled\n");
// e.g. due to PCI Master/Target Abort
+ if (ohci->flags & OHCI_QUIRK_NEC) {
+ /* Workaround for a silicon bug in some NEC chips used
+ * in Apple's PowerBooks. Adapted from Darwin code.
+ */
+ ohci_err (ohci, "OHCI Unrecoverable Error, scheduling NEC chip restart\n");
+
+ ohci_writel (ohci, OHCI_INTR_UE, &regs->intrdisable);
+
+ schedule_work (&ohci->nec_work);
+ } else {
+ disable (ohci);
+ ohci_err (ohci, "OHCI Unrecoverable Error, disabled\n");
+ }

ohci_dump (ohci, 1);
ohci_usb_reset (ohci);
@@ -763,9 +777,6 @@ static void ohci_stop (struct usb_hcd *h
/*-------------------------------------------------------------------------*/

/* must not be called from interrupt context */
-
-#ifdef CONFIG_PM
-
static int ohci_restart (struct ohci_hcd *ohci)
{
int temp;
@@ -839,7 +850,27 @@ static int ohci_restart (struct ohci_hcd
}
return 0;
}
-#endif
+
+/*-------------------------------------------------------------------------*/
+
+/* NEC workaround */
+static void ohci_quirk_nec_worker(struct work_struct *work)
+{
+ struct ohci_hcd *ohci = container_of(work, struct ohci_hcd, nec_work);
+ int status;
+
+ status = ohci_init(ohci);
+ if (status != 0) {
+ ohci_err(ohci, "Restarting NEC controller failed "
+ "in ohci_init, %d\n", status);
+ return;
+ }
+
+ status = ohci_restart(ohci);
+ if (status != 0)
+ ohci_err(ohci, "Restarting NEC controller failed "
+ "in ohci_restart, %d\n", status);
+}

/*-------------------------------------------------------------------------*/

diff -Nurp --exclude-from=linux-exclude-from linux-2.6.22-rc3.orig/drivers/usb/host/ohci-hub.c linux-2.6.22-rc3/drivers/usb/host/ohci-hub.c
--- linux-2.6.22-rc3.orig/drivers/usb/host/ohci-hub.c 2007-05-31 22:53:54.000000000 +0200
+++ linux-2.6.22-rc3/drivers/usb/host/ohci-hub.c 2007-05-31 22:54:27.000000000 +0200
@@ -55,8 +55,6 @@ static void dl_done_list (struct ohci_hc
static void finish_unlinks (struct ohci_hcd *, u16);

#ifdef CONFIG_PM
-static int ohci_restart(struct ohci_hcd *ohci);
-
static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
__releases(ohci->lock)
__acquires(ohci->lock)
diff -Nurp --exclude-from=linux-exclude-from linux-2.6.22-rc3.orig/drivers/usb/host/ohci-mem.c linux-2.6.22-rc3/drivers/usb/host/ohci-mem.c
--- linux-2.6.22-rc3.orig/drivers/usb/host/ohci-mem.c 2007-05-31 22:53:54.000000000 +0200
+++ linux-2.6.22-rc3/drivers/usb/host/ohci-mem.c 2007-05-31 23:24:43.000000000 +0200
@@ -28,6 +28,7 @@ static void ohci_hcd_init (struct ohci_h
ohci->next_statechange = jiffies;
spin_lock_init (&ohci->lock);
INIT_LIST_HEAD (&ohci->pending);
+ INIT_WORK (&ohci->nec_work, ohci_quirk_nec_worker);
}

/*-------------------------------------------------------------------------*/
diff -Nurp --exclude-from=linux-exclude-from linux-2.6.22-rc3.orig/drivers/usb/host/ohci-pci.c linux-2.6.22-rc3/drivers/usb/host/ohci-pci.c
--- linux-2.6.22-rc3.orig/drivers/usb/host/ohci-pci.c 2007-05-31 22:53:54.000000000 +0200
+++ linux-2.6.22-rc3/drivers/usb/host/ohci-pci.c 2007-05-31 22:54:27.000000000 +0200
@@ -111,6 +111,18 @@ static int ohci_quirk_toshiba_scc(struct
#endif
}

+/* Check for NEC chip and apply quirk for allegedly lost interrupts.
+ */
+static int ohci_quirk_nec(struct usb_hcd *hcd)
+{
+ struct ohci_hcd *ohci = hcd_to_ohci (hcd);
+
+ ohci->flags |= OHCI_QUIRK_NEC;
+ ohci_dbg (ohci, "enabled NEC chipset lost interrupt quirk\n");
+
+ return 0;
+}
+
/* List of quirks for OHCI */
static const struct pci_device_id ohci_pci_quirks[] = {
{
@@ -134,6 +146,10 @@ static const struct pci_device_id ohci_p
.driver_data = (unsigned long)ohci_quirk_toshiba_scc,
},
{
+ PCI_DEVICE(PCI_VENDOR_ID_NEC, PCI_DEVICE_ID_NEC_USB),
+ .driver_data = (unsigned long)ohci_quirk_nec,
+ },
+ {
/* Toshiba portege 4000 */
.vendor = PCI_VENDOR_ID_AL,
.device = 0x5237,
-
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