* [PATCH] usb/hcd: remove unnecessary local_irq_save
@ 2013-10-13 7:14 Michael Opdenacker
2013-10-13 15:35 ` Alan Stern
0 siblings, 1 reply; 4+ messages in thread
From: Michael Opdenacker @ 2013-10-13 7:14 UTC (permalink / raw)
To: gregkh
Cc: stern, sarah.a.sharp, tianyu.lan, broonie, linux-usb,
linux-kernel, Michael Opdenacker
Remove the use of local_irq_save() and IRQF_DISABLED, no longer needed since
interrupt handlers are always run with interrupts disabled on the
current CPU.
Tested successfully with 3.12.0-rc4 on my PC. Didn't find
any issue because of this change.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
---
drivers/usb/core/hcd.c | 15 ---------------
1 file changed, 15 deletions(-)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index d6a8d23..1c309f1 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2324,15 +2324,8 @@ EXPORT_SYMBOL_GPL(usb_bus_start_enum);
irqreturn_t usb_hcd_irq (int irq, void *__hcd)
{
struct usb_hcd *hcd = __hcd;
- unsigned long flags;
irqreturn_t rc;
- /* IRQF_DISABLED doesn't work correctly with shared IRQs
- * when the first handler doesn't use it. So let's just
- * assume it's never used.
- */
- local_irq_save(flags);
-
if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
rc = IRQ_NONE;
else if (hcd->driver->irq(hcd) == IRQ_NONE)
@@ -2340,7 +2333,6 @@ irqreturn_t usb_hcd_irq (int irq, void *__hcd)
else
rc = IRQ_HANDLED;
- local_irq_restore(flags);
return rc;
}
EXPORT_SYMBOL_GPL(usb_hcd_irq);
@@ -2547,13 +2539,6 @@ static int usb_hcd_request_irqs(struct usb_hcd *hcd,
if (hcd->driver->irq) {
- /* IRQF_DISABLED doesn't work as advertised when used together
- * with IRQF_SHARED. As usb_hcd_irq() will always disable
- * interrupts we can remove it here.
- */
- if (irqflags & IRQF_SHARED)
- irqflags &= ~IRQF_DISABLED;
-
snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
hcd->driver->description, hcd->self.busnum);
retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
--
1.8.1.2
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] usb/hcd: remove unnecessary local_irq_save
2013-10-13 7:14 [PATCH] usb/hcd: remove unnecessary local_irq_save Michael Opdenacker
@ 2013-10-13 15:35 ` Alan Stern
2013-10-14 3:23 ` Michael Opdenacker
0 siblings, 1 reply; 4+ messages in thread
From: Alan Stern @ 2013-10-13 15:35 UTC (permalink / raw)
To: Michael Opdenacker
Cc: gregkh, sarah.a.sharp, tianyu.lan, broonie, linux-usb,
linux-kernel
On Sun, 13 Oct 2013, Michael Opdenacker wrote:
> Remove the use of local_irq_save() and IRQF_DISABLED, no longer needed since
> interrupt handlers are always run with interrupts disabled on the
> current CPU.
>
> Tested successfully with 3.12.0-rc4 on my PC. Didn't find
> any issue because of this change.
>
> Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
> ---
> drivers/usb/core/hcd.c | 15 ---------------
> 1 file changed, 15 deletions(-)
How about removing all the other unnecessary usages of IRQF_DISABLED
under drivers/usb while you're at it?
Alan Stern
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] usb/hcd: remove unnecessary local_irq_save
2013-10-13 15:35 ` Alan Stern
@ 2013-10-14 3:23 ` Michael Opdenacker
2013-10-14 19:48 ` Alan Stern
0 siblings, 1 reply; 4+ messages in thread
From: Michael Opdenacker @ 2013-10-14 3:23 UTC (permalink / raw)
To: Alan Stern
Cc: gregkh, sarah.a.sharp, tianyu.lan, broonie, linux-usb,
linux-kernel
Hi Alan,
On 10/13/2013 05:35 PM, Alan Stern wrote:
> On Sun, 13 Oct 2013, Michael Opdenacker wrote:
>
>> Remove the use of local_irq_save() and IRQF_DISABLED, no longer needed since
>> interrupt handlers are always run with interrupts disabled on the
>> current CPU.
>>
>> Tested successfully with 3.12.0-rc4 on my PC. Didn't find
>> any issue because of this change.
>>
>> Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
>> ---
>> drivers/usb/core/hcd.c | 15 ---------------
>> 1 file changed, 15 deletions(-)
> How about removing all the other unnecessary usages of IRQF_DISABLED
> under drivers/usb while you're at it?
I believe I already did, through patches sent on Oct. 6:
drivers/usb/gadget/mv_u3d_core.c: IRQF_DISABLED |
IRQF_SHARED, driver_name, u3d)) {
=> Sent fix on Oct. 6, 2013
drivers/usb/host/uhci-platform.c: ret = usb_add_hcd(hcd,
pdev->resource[1].start, IRQF_DISABLED |
=> Sent fix on Oct. 6, 2013
Cheers,
Michael.
--
Michael Opdenacker, CEO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
+33 484 258 098
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] usb/hcd: remove unnecessary local_irq_save
2013-10-14 3:23 ` Michael Opdenacker
@ 2013-10-14 19:48 ` Alan Stern
0 siblings, 0 replies; 4+ messages in thread
From: Alan Stern @ 2013-10-14 19:48 UTC (permalink / raw)
To: Michael Opdenacker
Cc: gregkh, sarah.a.sharp, tianyu.lan, broonie, linux-usb,
linux-kernel
On Mon, 14 Oct 2013, Michael Opdenacker wrote:
> Hi Alan,
>
> On 10/13/2013 05:35 PM, Alan Stern wrote:
> > On Sun, 13 Oct 2013, Michael Opdenacker wrote:
> >
> >> Remove the use of local_irq_save() and IRQF_DISABLED, no longer needed since
> >> interrupt handlers are always run with interrupts disabled on the
> >> current CPU.
> >>
> >> Tested successfully with 3.12.0-rc4 on my PC. Didn't find
> >> any issue because of this change.
> >>
> >> Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
> >> ---
> >> drivers/usb/core/hcd.c | 15 ---------------
> >> 1 file changed, 15 deletions(-)
> > How about removing all the other unnecessary usages of IRQF_DISABLED
> > under drivers/usb while you're at it?
> I believe I already did, through patches sent on Oct. 6:
>
> drivers/usb/gadget/mv_u3d_core.c: IRQF_DISABLED |
> IRQF_SHARED, driver_name, u3d)) {
> => Sent fix on Oct. 6, 2013
>
> drivers/usb/host/uhci-platform.c: ret = usb_add_hcd(hcd,
> pdev->resource[1].start, IRQF_DISABLED |
> => Sent fix on Oct. 6, 2013
Ah, I had forgotten about those submissions. No further objections.
Alan Stern
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-10-14 19:48 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2013-10-13 7:14 [PATCH] usb/hcd: remove unnecessary local_irq_save Michael Opdenacker
2013-10-13 15:35 ` Alan Stern
2013-10-14 3:23 ` Michael Opdenacker
2013-10-14 19:48 ` Alan Stern
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