On Wed, 5 Dec 2007, David Brownell wrote:
> On Wednesday 05 December 2007, Alan Stern wrote:
> > But it will be easy enough to add IRQF_DISABLED in. Only a few drivers
> > omit it.
>
> I forgot that the flags are passed in to usb_add_hcd()... if we
> go that route, the drivers that don't pass it should be updated
> and so should hcd-pci.c; that seems the safest option to me.
The proposed patch is below.
> This looks like a longstanding bug/oversight. Color me surprised.
It's possible that it has caused undiagnosed lockups in the past. The
recent changes for urb->status removal must have made them much more
likely. For instance, the urb_unlink() routine formerly in hcd.c
used spin_lock_irqsave() but its replacement
usb_hcd_unlink_urb_from_ep() uses only spin_lock(). That particular
spinlock is what led to the bug report.
Alan Stern
Host controller IRQs are supposed to be serviced with interrupts
disabled. This patch (as1025) adds an IRQF_DISABLED flag to all the
controller drivers that lack it. It also replaces the
spin_lock_irqsave() and spin_unlock_irqrestore() calls in uhci_irq()
with simple spin_lock() and spin_unlock().
This fixes Bugzilla #9335.
Signed-off-by: Alan Stern <[EMAIL PROTECTED]>
---
Index: usb-2.6/drivers/usb/core/hcd-pci.c
===================================================================
--- usb-2.6.orig/drivers/usb/core/hcd-pci.c
+++ usb-2.6/drivers/usb/core/hcd-pci.c
@@ -125,7 +125,7 @@ int usb_hcd_pci_probe (struct pci_dev *d
pci_set_master (dev);
- retval = usb_add_hcd (hcd, dev->irq, IRQF_SHARED);
+ retval = usb_add_hcd(hcd, dev->irq, IRQF_DISABLED | IRQF_SHARED);
if (retval != 0)
goto err4;
return retval;
Index: usb-2.6/drivers/usb/host/ehci-fsl.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-fsl.c
+++ usb-2.6/drivers/usb/host/ehci-fsl.c
@@ -122,7 +122,7 @@ int usb_hcd_fsl_probe(const struct hc_dr
temp = in_le32(hcd->regs + 0x1a8);
out_le32(hcd->regs + 0x1a8, temp | 0x3);
- retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
+ retval = usb_add_hcd(hcd, irq, IRQF_DISABLED | IRQF_SHARED);
if (retval != 0)
goto err4;
return retval;
Index: usb-2.6/drivers/usb/host/ohci-ppc-of.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ohci-ppc-of.c
+++ usb-2.6/drivers/usb/host/ohci-ppc-of.c
@@ -142,7 +142,7 @@ ohci_hcd_ppc_of_probe(struct of_device *
ohci_hcd_init(ohci);
- rv = usb_add_hcd(hcd, irq, 0);
+ rv = usb_add_hcd(hcd, irq, IRQF_DISABLED);
if (rv == 0)
return 0;
Index: usb-2.6/drivers/usb/host/ohci-ssb.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ohci-ssb.c
+++ usb-2.6/drivers/usb/host/ohci-ssb.c
@@ -160,7 +160,7 @@ static int ssb_ohci_attach(struct ssb_de
hcd->regs = ioremap_nocache(hcd->rsrc_start, hcd->rsrc_len);
if (!hcd->regs)
goto err_put_hcd;
- err = usb_add_hcd(hcd, dev->irq, IRQF_SHARED);
+ err = usb_add_hcd(hcd, dev->irq, IRQF_DISABLED | IRQF_SHARED);
if (err)
goto err_iounmap;
Index: usb-2.6/drivers/usb/host/r8a66597-hcd.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/r8a66597-hcd.c
+++ usb-2.6/drivers/usb/host/r8a66597-hcd.c
@@ -2197,7 +2197,7 @@ static int __init r8a66597_probe(struct
INIT_LIST_HEAD(&r8a66597->child_device);
hcd->rsrc_start = res->start;
- ret = usb_add_hcd(hcd, irq, 0);
+ ret = usb_add_hcd(hcd, irq, IRQF_DISABLED);
if (ret != 0) {
err("Failed to add hcd");
goto clean_up;
Index: usb-2.6/drivers/usb/host/uhci-hcd.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/uhci-hcd.c
+++ usb-2.6/drivers/usb/host/uhci-hcd.c
@@ -378,7 +378,6 @@ static irqreturn_t uhci_irq(struct usb_h
{
struct uhci_hcd *uhci = hcd_to_uhci(hcd);
unsigned short status;
- unsigned long flags;
/*
* Read the interrupt status, and write it back to clear the
@@ -398,7 +397,7 @@ static irqreturn_t uhci_irq(struct usb_h
dev_err(uhci_dev(uhci), "host controller process "
"error, something bad happened!\n");
if (status & USBSTS_HCH) {
- spin_lock_irqsave(&uhci->lock, flags);
+ spin_lock(&uhci->lock);
if (uhci->rh_state >= UHCI_RH_RUNNING) {
dev_err(uhci_dev(uhci),
"host controller halted, "
@@ -415,16 +414,16 @@ static irqreturn_t uhci_irq(struct usb_h
* pending unlinks */
mod_timer(&hcd->rh_timer, jiffies);
}
- spin_unlock_irqrestore(&uhci->lock, flags);
+ spin_unlock(&uhci->lock);
}
}
if (status & USBSTS_RD)
usb_hcd_poll_rh_status(hcd);
else {
- spin_lock_irqsave(&uhci->lock, flags);
+ spin_lock(&uhci->lock);
uhci_scan_schedule(uhci);
- spin_unlock_irqrestore(&uhci->lock, flags);
+ spin_unlock(&uhci->lock);
}
return IRQ_HANDLED;
-
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