Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1190880 > unrolled thread

[PATCH] usb/gadget: make composite gadget meet usb compliance for vbus draw

Back to article view | Back to linux.kernel

Contents

  [PATCH] usb/gadget: make composite gadget meet usb compliance for  vbus draw "Du, Changbin" <changbin.du@intel.com> - 2015-07-23 14:40 +0200
    Re: [PATCH] usb/gadget: make composite gadget meet usb compliance for  vbus draw Andrzej Pietrasiewicz <andrzej.p@samsung.com> - 2015-07-24 09:40 +0200
      RE: [PATCH] usb/gadget: make composite gadget meet usb compliance  for vbus draw "Du, Changbin" <changbin.du@intel.com> - 2015-07-24 10:40 +0200

#1190880 — [PATCH] usb/gadget: make composite gadget meet usb compliance for vbus draw

From 0a8e0d63a9887735c6782d7b0c15c2c1fdf1952a Mon Sep 17 00:00:00 2001
From: "Du, Changbin" <changbin.du@intel.com>
Date: Thu, 23 Jul 2015 20:08:04 +0800
Subject: [PATCH] usb/gadget: make composite gadget meet usb compliance for
 vbus draw

USB-IF compliance requirement limits the vbus current according to
current state. USB2 Spec requires that un-configured current must
be <= 100mA, for USB3 is 150mA, OTG is 2.5mA. So set corresponding
vbus draw current according to device mode.

Signed-off-by: Du, Changbin <changbin.du@intel.com>
---
 drivers/usb/gadget/composite.c | 39 ++++++++++++++++++++++++++++++++-------
 include/linux/usb/composite.h  |  8 ++++++++
 2 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 4e3447b..fdfd625 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -610,6 +610,21 @@ static void device_qual(struct usb_composite_dev *cdev)
 	qual->bRESERVED = 0;
 }
 
+static unsigned unconfigured_vbus_draw(struct usb_composite_dev *cdev)
+{
+	struct usb_gadget *g = cdev->gadget;
+	unsigned power;
+
+	if (gadget_is_otg(g))
+		power = USB_OTG_VBUS_DRAW_UNCONF;
+	else if (g->speed == USB_SPEED_SUPER)
+		power = USB3_VBUS_DRAW_UNCONF;
+	else
+		power = USB2_VBUS_DRAW_UNCONF;
+
+	return power;
+}
+
 /*-------------------------------------------------------------------------*/
 
 static void reset_config(struct usb_composite_dev *cdev)
@@ -634,7 +649,7 @@ static int set_config(struct usb_composite_dev *cdev,
 	struct usb_gadget	*gadget = cdev->gadget;
 	struct usb_configuration *c = NULL;
 	int			result = -EINVAL;
-	unsigned		power = gadget_is_otg(gadget) ? 8 : 100;
+	unsigned		power = unconfigured_vbus_draw(cdev);
 	int			tmp;
 
 	if (number) {
@@ -1829,6 +1844,15 @@ done:
 	return value;
 }
 
+static void composite_reset(struct usb_gadget *gadget)
+{
+	struct usb_composite_dev *cdev = get_gadget_data(gadget);
+
+	DBG(cdev, "reset\n");
+	usb_gadget_vbus_draw(gadget, unconfigured_vbus_draw(cdev));
+	composite_disconnect(gadget);
+}
+
 void composite_disconnect(struct usb_gadget *gadget)
 {
 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
@@ -2095,7 +2119,7 @@ void composite_suspend(struct usb_gadget *gadget)
 
 	cdev->suspended = 1;
 
-	usb_gadget_vbus_draw(gadget, 2);
+	usb_gadget_vbus_draw(gadget, USB_VBUS_DRAW_SUSPEND);
 }
 
 void composite_resume(struct usb_gadget *gadget)
@@ -2117,10 +2141,11 @@ void composite_resume(struct usb_gadget *gadget)
 		}
 
 		maxpower = cdev->config->MaxPower;
-
-		usb_gadget_vbus_draw(gadget, maxpower ?
-			maxpower : CONFIG_USB_GADGET_VBUS_DRAW);
-	}
+		if (!maxpower)
+			maxpower = CONFIG_USB_GADGET_VBUS_DRAW;
+	} else
+		maxpower = unconfigured_vbus_draw(cdev);
+	usb_gadget_vbus_draw(gadget, maxpower);
 
 	cdev->suspended = 0;
 }
@@ -2132,7 +2157,7 @@ static const struct usb_gadget_driver composite_driver_template = {
 	.unbind		= composite_unbind,
 
 	.setup		= composite_setup,
-	.reset		= composite_disconnect,
+	.reset		= composite_reset,
 	.disconnect	= composite_disconnect,
 
 	.suspend	= composite_suspend,
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 2511469..90b434d 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -333,6 +333,14 @@ enum {
 	USB_GADGET_FIRST_AVAIL_IDX,
 };
 
+/* USB2 compliance requires that un-configured current draw <= 100mA,
+ * USB3 requires it <= 150mA, OTG requires it <= 2.5mA.
+ */
+#define USB2_VBUS_DRAW_UNCONF		100
+#define USB3_VBUS_DRAW_UNCONF		150
+#define USB_OTG_VBUS_DRAW_UNCONF	2
+#define USB_VBUS_DRAW_SUSPEND		2
+
 /**
  * struct usb_composite_driver - groups configurations into a gadget
  * @name: For diagnostics, identifies the driver.
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [next] | [standalone]

#1191577

Hi,

W dniu 24.07.2015 o 06:11, Du, Changbin pisze:
> Thanks, Pietrasiewicz.
>> From: Andrzej Pietrasiewicz [mailto:andrzej.p@samsung.com]
>> W dniu 23.07.2015 o 14:34, Du, Changbin pisze:
>>> >From 0a8e0d63a9887735c6782d7b0c15c2c1fdf1952a Mon Sep 17 00:00:00
>>>    void composite_disconnect(struct usb_gadget *gadget)
>>>    {
>>>    	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
>>> @@ -2095,7 +2119,7 @@ void composite_suspend(struct usb_gadget
>> *gadget)
>>>
>>>    	cdev->suspended = 1;
>>>
>>> -	usb_gadget_vbus_draw(gadget, 2);
>>> +	usb_gadget_vbus_draw(gadget, USB_VBUS_DRAW_SUSPEND);
>>>    }
>>
>> This looks like an unrelated change. I think it should go first
>> in a separate patch which eliminates usage of "magic" numbers.
>>
> This change does make sense. As you know, when device is reset, it is in a 'unconfigured'
> state. Compliance Test equipment may also measure vbus current at this moment.

I am not questioning the change itself.

What I mean is that in my opinion it should be done in a separate patch,
because the newly introduced USB_VBUS_DRAW_SUSPEND is not used
anywhere else in your patch. The meaning of this change is "use a symbolic
name rather than an explicit number" and it is unrelated to
making composite gadget meet usb compliance for vbus draw. In other words,
if you don't do this change at all the compliance is still maintained,
because the value of USB_VBUS_DRAW_SUSPEND is 2 anyway, so what the
compiler eventually sees is the same whether the change is made or not.

My idea:

[PATCHv2 0/2] usb gadget vbus draw compilance
   [PATCHv2 1/2] usb: gadget: composite: avoid using a magic number
       >> substituting an explicit "2" with USB_VBUS_DRAW_SUSPEND goes here <<
   [PATCHv2 2/2] usb: gadget: composite: meet usb compliance for vbus draw
       >> the rest of your changes go here <<

>
>>>    }
>>> @@ -2132,7 +2157,7 @@ static const struct usb_gadget_driver
>> composite_driver_template = {
>>>    	.unbind		= composite_unbind,
>>>
>>>    	.setup		= composite_setup,
>>> -	.reset		= composite_disconnect,
>>> +	.reset		= composite_reset,
>>>    	.disconnect	= composite_disconnect,
>>>
>>
>> A similar "template" is in drivers/usb/gadget/configfs.c. Shouldn't the "reset"
>> method be changed there as well?
>>
> Yes, it also need to change. I will change it as well.
>
>>
>>>
>>> +/* USB2 compliance requires that un-configured current draw <= 100mA,
>>> + * USB3 requires it <= 150mA, OTG requires it <= 2.5mA.
>>> + */
>>> +#define USB2_VBUS_DRAW_UNCONF		100
>>> +#define USB3_VBUS_DRAW_UNCONF		150
>>> +#define USB_OTG_VBUS_DRAW_UNCONF	2
>>
>>
>>> +#define USB_VBUS_DRAW_SUSPEND		2
>>
>> separate patch
>>
> Sorry, I didn't get your idea. Why separate these macros definition?

Please see above.

Andrzej

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [next] | [standalone]

#1191599 — RE: [PATCH] usb/gadget: make composite gadget meet usb compliance for vbus draw

Thanks for explanation. I am agree with you that separate changes into two patches.
Will send out new patch soon.

Regards
Du, Changbin

> From: Andrzej Pietrasiewicz [mailto:andrzej.p@samsung.com]
> Hi,
> 
> W dniu 24.07.2015 o 06:11, Du, Changbin pisze:
> > Thanks, Pietrasiewicz.
> >> From: Andrzej Pietrasiewicz [mailto:andrzej.p@samsung.com]
> >> W dniu 23.07.2015 o 14:34, Du, Changbin pisze:
> >>> >From 0a8e0d63a9887735c6782d7b0c15c2c1fdf1952a Mon Sep 17
> 00:00:00
> >>>    void composite_disconnect(struct usb_gadget *gadget)
> >>>    {
> >>>    	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
> >>> @@ -2095,7 +2119,7 @@ void composite_suspend(struct usb_gadget
> >> *gadget)
> >>>
> >>>    	cdev->suspended = 1;
> >>>
> >>> -	usb_gadget_vbus_draw(gadget, 2);
> >>> +	usb_gadget_vbus_draw(gadget, USB_VBUS_DRAW_SUSPEND);
> >>>    }
> >>
> >> This looks like an unrelated change. I think it should go first
> >> in a separate patch which eliminates usage of "magic" numbers.
> >>
> > This change does make sense. As you know, when device is reset, it is in a
> 'unconfigured'
> > state. Compliance Test equipment may also measure vbus current at this
> moment.
> 
> I am not questioning the change itself.
> 
> What I mean is that in my opinion it should be done in a separate patch,
> because the newly introduced USB_VBUS_DRAW_SUSPEND is not used
> anywhere else in your patch. The meaning of this change is "use a symbolic
> name rather than an explicit number" and it is unrelated to
> making composite gadget meet usb compliance for vbus draw. In other
> words,
> if you don't do this change at all the compliance is still maintained,
> because the value of USB_VBUS_DRAW_SUSPEND is 2 anyway, so what the
> compiler eventually sees is the same whether the change is made or not.
> 
> My idea:
> 
> [PATCHv2 0/2] usb gadget vbus draw compilance
>    [PATCHv2 1/2] usb: gadget: composite: avoid using a magic number
>        >> substituting an explicit "2" with USB_VBUS_DRAW_SUSPEND goes
> here <<
>    [PATCHv2 2/2] usb: gadget: composite: meet usb compliance for vbus draw
>        >> the rest of your changes go here <<
> 
> >
> >>>    }
> >>> @@ -2132,7 +2157,7 @@ static const struct usb_gadget_driver
> >> composite_driver_template = {
> >>>    	.unbind		= composite_unbind,
> >>>
> >>>    	.setup		= composite_setup,
> >>> -	.reset		= composite_disconnect,
> >>> +	.reset		= composite_reset,
> >>>    	.disconnect	= composite_disconnect,
> >>>
> >>
> >> A similar "template" is in drivers/usb/gadget/configfs.c. Shouldn't the
> "reset"
> >> method be changed there as well?
> >>
> > Yes, it also need to change. I will change it as well.
> >
> >>
> >>>
> >>> +/* USB2 compliance requires that un-configured current draw <=
> 100mA,
> >>> + * USB3 requires it <= 150mA, OTG requires it <= 2.5mA.
> >>> + */
> >>> +#define USB2_VBUS_DRAW_UNCONF		100
> >>> +#define USB3_VBUS_DRAW_UNCONF		150
> >>> +#define USB_OTG_VBUS_DRAW_UNCONF	2
> >>
> >>
> >>> +#define USB_VBUS_DRAW_SUSPEND		2
> >>
> >> separate patch
> >>
> > Sorry, I didn't get your idea. Why separate these macros definition?
> 
> Please see above.
> 
> Andrzej

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web