Re: [PATCH 2/2] gadget: Support for the usb charger framework
On 8 August 2015 at 01:53, Greg KH gre...@linuxfoundation.org wrote:
On Fri, Aug 07, 2015 at 05:22:47PM +0800, Baolin Wang wrote:
On 7 August 2015 at 17:07, Peter Chen peter.c...@freescale.com wrote:
/**
* struct usb_udc - describes one usb device controller @@ -127,12
+128,45 @@ void usb_gadget_giveback_request(struct usb_ep *ep, }
EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
+int usb_gadget_register_notify(struct usb_gadget *gadget,
+struct notifier_block *nb) {
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(gadget-lock, flags);
I find you use so many spin_lock_irqsave, any reasons for that?
Why mutex_lock can't be used?
The spin_lock_irqsave() can make it as a atomic notifier, that can make
sure the
gadget state event can be quickly reported to the user who register a
notifier
on the gadget device. Is it OK?
I don't think it is a good reason, spin_lock_irqsave is usually used for
protecting
data which is accessed at atomic environment.
Yes, we want the notify process is a atomic environment which do not
want to be interrupted by irq or other things to make the notice can
be quickly reported to the user.
No, this is a slow event, you don't need to notify anyone under atomic
context, that's crazy.
Also i think the notify process is less cost, thus i use the spinlock.
Thanks.
No, use a mutex please, that's the safe thing. This is not
time-critical code at all.
OK, Thanks for your comments and will fix the lock thing.
thanks,
greg k-h
--
Baolin.wang
Best Regards
--
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RE: [PATCH 2/2] gadget: Support for the usb charger framework
/**
* struct usb_udc - describes one usb device controller @@ -127,12
+128,45 @@ void usb_gadget_giveback_request(struct usb_ep *ep, }
EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
+int usb_gadget_register_notify(struct usb_gadget *gadget,
+struct notifier_block *nb) {
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(gadget-lock, flags);
I find you use so many spin_lock_irqsave, any reasons for that?
Why mutex_lock can't be used?
The spin_lock_irqsave() can make it as a atomic notifier, that can make sure
the
gadget state event can be quickly reported to the user who register a notifier
on the gadget device. Is it OK?
I don't think it is a good reason, spin_lock_irqsave is usually used for
protecting
data which is accessed at atomic environment.
Peter
Re: [PATCH 2/2] gadget: Support for the usb charger framework
On Thu, Aug 06, 2015 at 03:03:49PM +0800, Baolin Wang wrote:
The usb charger framework is based on usb gadget, and each usb gadget
can be one usb charger to set the current limitation.
This patch adds a notifier mechanism for usb charger to report to usb
charger when the usb gadget state is changed.
Also we introduce a callback 'get_charger_type' which will implemented
by user for usb gadget operations to get the usb charger type.
Signed-off-by: Baolin Wang baolin.w...@linaro.org
---
drivers/usb/gadget/udc/udc-core.c | 41
+
include/linux/usb/gadget.h| 20 ++
2 files changed, 61 insertions(+)
diff --git a/drivers/usb/gadget/udc/udc-core.c
b/drivers/usb/gadget/udc/udc-core.c
index d69c355..d5368088 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -28,6 +28,7 @@
#include linux/usb/ch9.h
#include linux/usb/gadget.h
#include linux/usb.h
+#include linux/usb/usb_charger.h
/**
* struct usb_udc - describes one usb device controller
@@ -127,12 +128,45 @@ void usb_gadget_giveback_request(struct usb_ep *ep,
}
EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
+int usb_gadget_register_notify(struct usb_gadget *gadget,
+struct notifier_block *nb)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(gadget-lock, flags);
I find you use so many spin_lock_irqsave, any reasons for that?
Why mutex_lock can't be used?
--
Best Regards,
Peter Chen
--
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the body of a message to majord...@vger.kernel.org
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Re: [PATCH 2/2] gadget: Support for the usb charger framework
On 7 August 2015 at 13:45, Peter Chen peter.c...@freescale.com wrote:
On Thu, Aug 06, 2015 at 03:03:49PM +0800, Baolin Wang wrote:
The usb charger framework is based on usb gadget, and each usb gadget
can be one usb charger to set the current limitation.
This patch adds a notifier mechanism for usb charger to report to usb
charger when the usb gadget state is changed.
Also we introduce a callback 'get_charger_type' which will implemented
by user for usb gadget operations to get the usb charger type.
Signed-off-by: Baolin Wang baolin.w...@linaro.org
---
drivers/usb/gadget/udc/udc-core.c | 41
+
include/linux/usb/gadget.h| 20 ++
2 files changed, 61 insertions(+)
diff --git a/drivers/usb/gadget/udc/udc-core.c
b/drivers/usb/gadget/udc/udc-core.c
index d69c355..d5368088 100644
--- a/drivers/usb/gadget/udc/udc-core.c
+++ b/drivers/usb/gadget/udc/udc-core.c
@@ -28,6 +28,7 @@
#include linux/usb/ch9.h
#include linux/usb/gadget.h
#include linux/usb.h
+#include linux/usb/usb_charger.h
/**
* struct usb_udc - describes one usb device controller
@@ -127,12 +128,45 @@ void usb_gadget_giveback_request(struct usb_ep *ep,
}
EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
+int usb_gadget_register_notify(struct usb_gadget *gadget,
+struct notifier_block *nb)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(gadget-lock, flags);
I find you use so many spin_lock_irqsave, any reasons for that?
Why mutex_lock can't be used?
The spin_lock_irqsave() can make it as a atomic notifier, that can
make sure the gadget state event can be quickly reported to the user
who register a notifier on the gadget device. Is it OK?
--
Best Regards,
Peter Chen
--
Baolin.wang
Best Regards
--
To unsubscribe from this list: send the line unsubscribe linux-usb in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/2] gadget: Support for the usb charger framework
On 7 August 2015 at 17:07, Peter Chen peter.c...@freescale.com wrote:
/**
* struct usb_udc - describes one usb device controller @@ -127,12
+128,45 @@ void usb_gadget_giveback_request(struct usb_ep *ep, }
EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
+int usb_gadget_register_notify(struct usb_gadget *gadget,
+struct notifier_block *nb) {
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(gadget-lock, flags);
I find you use so many spin_lock_irqsave, any reasons for that?
Why mutex_lock can't be used?
The spin_lock_irqsave() can make it as a atomic notifier, that can make sure
the
gadget state event can be quickly reported to the user who register a
notifier
on the gadget device. Is it OK?
I don't think it is a good reason, spin_lock_irqsave is usually used for
protecting
data which is accessed at atomic environment.
Yes, we want the notify process is a atomic environment which do not
want to be interrupted by irq or other things to make the notice can
be quickly reported to the user.
Also i think the notify process is less cost, thus i use the spinlock. Thanks.
Peter
--
Baolin.wang
Best Regards
--
To unsubscribe from this list: send the line unsubscribe linux-usb in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 2/2] gadget: Support for the usb charger framework
On Fri, Aug 07, 2015 at 05:22:47PM +0800, Baolin Wang wrote:
On 7 August 2015 at 17:07, Peter Chen peter.c...@freescale.com wrote:
/**
* struct usb_udc - describes one usb device controller @@ -127,12
+128,45 @@ void usb_gadget_giveback_request(struct usb_ep *ep, }
EXPORT_SYMBOL_GPL(usb_gadget_giveback_request);
+int usb_gadget_register_notify(struct usb_gadget *gadget,
+struct notifier_block *nb) {
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(gadget-lock, flags);
I find you use so many spin_lock_irqsave, any reasons for that?
Why mutex_lock can't be used?
The spin_lock_irqsave() can make it as a atomic notifier, that can make
sure the
gadget state event can be quickly reported to the user who register a
notifier
on the gadget device. Is it OK?
I don't think it is a good reason, spin_lock_irqsave is usually used for
protecting
data which is accessed at atomic environment.
Yes, we want the notify process is a atomic environment which do not
want to be interrupted by irq or other things to make the notice can
be quickly reported to the user.
No, this is a slow event, you don't need to notify anyone under atomic
context, that's crazy.
Also i think the notify process is less cost, thus i use the spinlock. Thanks.
No, use a mutex please, that's the safe thing. This is not
time-critical code at all.
thanks,
greg k-h
--
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the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
