Re: [PATCH v5 01/46] usb: gadget: encapsulate endpoint claiming mechanism
On 8/20/2015 10:45 AM, Felipe Balbi wrote:
> Hi,
>
> On Thu, Aug 20, 2015 at 07:16:48PM +0200, Robert Baldyga wrote:
>> On 08/20/2015 06:48 PM, Felipe Balbi wrote:
>>> On Thu, Aug 20, 2015 at 06:28:14PM +0200, Robert Baldyga wrote:
Hi Felipe,
On 08/20/2015 05:35 PM, Felipe Balbi wrote:
[...]
> just letting you know that this regresses all gadget drivers making them
> try to disable previously disabled endpoints and enable previously
> enabled endpoints.
>
> I have a possible fix (see below) but then it shows a problem on the
> host side when using with g_zero (see further below):
>
> commit 3b8932100aacb6cfbffe288ca93025d8b8430c00
> Author: Felipe Balbi
> Date: Wed Aug 19 18:05:27 2015 -0500
>
> usb: gadget: fix ep->claimed lifetime
>
> In order to fix a regression introduced by commit
> cc476b42a39d ("usb: gadget: encapsulate endpoint
> claiming mechanism") we have to introduce a simple
> helper to check if a particular is enabled or not.
>
> After that, we need to move ep->claimed lifetime to
> usb_ep_enable() and usb_ep_disable() since those
> are the only functions which actually enable and
> disable endpoints.
>
> A follow-up patch will come to drop all driver_data
> checks from function drivers, since those are, now,
> pointless.
>
> Fixes: cc476b42a39d ("usb: gadget: encapsulate endpoint
> claiming mechanism")
> Cc: Robert Baldyga
> Signed-off-by: Felipe Balbi
>
> diff --git a/drivers/usb/gadget/epautoconf.c
> b/drivers/usb/gadget/epautoconf.c
> index 978435a51038..ad45070cd76f 100644
> --- a/drivers/usb/gadget/epautoconf.c
> +++ b/drivers/usb/gadget/epautoconf.c
> @@ -126,7 +126,6 @@ found_ep:
> ep->address = desc->bEndpointAddress;
> ep->desc = NULL;
> ep->comp_desc = NULL;
> - ep->claimed = true;
Removing this line causes autoconfig can return the same endpoint many
times. This probably causes problems with g_zero.
I will try to fix it ASAP.
>>>
>>> I was considering the same thing, but the lifetime of ->claimed doesn't
>>> look correct to me either way. Note that once the flag is enabled, it
>>> won't get disabled by most gadget drivers.
>>
>> And it should not be. This flag is indicator, that endpoint is used by some
>> function. It should be set once by usb_ep_autoconfig() and cleared by
>> usb_ep_autoconfig_reset().
And the 'claimed' flag should be used for the ep autoconfig
mechanism alone. We may want to reset it during the autoconfig
phase for multiple configs and alt-interfaces. So there should be
separate 'claimed' and 'enabled' flags.
>
> have you considered switching interfaces and/or alternate settings ?
We ran into similar issues before with this very scenario. Handling
of set_config(0 or N), in both addressed and configured states, and
set_interface requests.
John
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Re: [PATCH v5 01/46] usb: gadget: encapsulate endpoint claiming mechanism
Hi,
On Thu, Aug 20, 2015 at 07:16:48PM +0200, Robert Baldyga wrote:
> On 08/20/2015 06:48 PM, Felipe Balbi wrote:
> >On Thu, Aug 20, 2015 at 06:28:14PM +0200, Robert Baldyga wrote:
> >>Hi Felipe,
> >>
> >>On 08/20/2015 05:35 PM, Felipe Balbi wrote:
> >>[...]
> >>>just letting you know that this regresses all gadget drivers making them
> >>>try to disable previously disabled endpoints and enable previously
> >>>enabled endpoints.
> >>>
> >>>I have a possible fix (see below) but then it shows a problem on the
> >>>host side when using with g_zero (see further below):
> >>>
> >>>commit 3b8932100aacb6cfbffe288ca93025d8b8430c00
> >>>Author: Felipe Balbi
> >>>Date: Wed Aug 19 18:05:27 2015 -0500
> >>>
> >>> usb: gadget: fix ep->claimed lifetime
> >>>
> >>> In order to fix a regression introduced by commit
> >>> cc476b42a39d ("usb: gadget: encapsulate endpoint
> >>> claiming mechanism") we have to introduce a simple
> >>> helper to check if a particular is enabled or not.
> >>>
> >>> After that, we need to move ep->claimed lifetime to
> >>> usb_ep_enable() and usb_ep_disable() since those
> >>> are the only functions which actually enable and
> >>> disable endpoints.
> >>>
> >>> A follow-up patch will come to drop all driver_data
> >>> checks from function drivers, since those are, now,
> >>> pointless.
> >>>
> >>> Fixes: cc476b42a39d ("usb: gadget: encapsulate endpoint
> >>> claiming mechanism")
> >>> Cc: Robert Baldyga
> >>> Signed-off-by: Felipe Balbi
> >>>
> >>>diff --git a/drivers/usb/gadget/epautoconf.c
> >>>b/drivers/usb/gadget/epautoconf.c
> >>>index 978435a51038..ad45070cd76f 100644
> >>>--- a/drivers/usb/gadget/epautoconf.c
> >>>+++ b/drivers/usb/gadget/epautoconf.c
> >>>@@ -126,7 +126,6 @@ found_ep:
> >>> ep->address = desc->bEndpointAddress;
> >>> ep->desc = NULL;
> >>> ep->comp_desc = NULL;
> >>>- ep->claimed = true;
> >>
> >>Removing this line causes autoconfig can return the same endpoint many
> >>times. This probably causes problems with g_zero.
> >>
> >>I will try to fix it ASAP.
> >
> >I was considering the same thing, but the lifetime of ->claimed doesn't
> >look correct to me either way. Note that once the flag is enabled, it
> >won't get disabled by most gadget drivers.
>
> And it should not be. This flag is indicator, that endpoint is used by some
> function. It should be set once by usb_ep_autoconfig() and cleared by
> usb_ep_autoconfig_reset().
have you considered switching interfaces and/or alternate settings ?
> I wonder what is reason of this enable/disable regression. Maybe the problem
> is that we don't set ep->driver_data to NULL in usb_ep_autoconfig_reset()
> (so far it was done). Does this problem occur while gadget is binded to UDC
> for the first time, or at any next time? Unfortunately at this moment I
> don't have access to my hardware, so it will take a moment before I will
> setup some testing environment.
yeah, that's okay. We've got time.
--
balbi
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Re: [PATCH v5 01/46] usb: gadget: encapsulate endpoint claiming mechanism
On 08/20/2015 06:48 PM, Felipe Balbi wrote:
On Thu, Aug 20, 2015 at 06:28:14PM +0200, Robert Baldyga wrote:
Hi Felipe,
On 08/20/2015 05:35 PM, Felipe Balbi wrote:
[...]
just letting you know that this regresses all gadget drivers making them
try to disable previously disabled endpoints and enable previously
enabled endpoints.
I have a possible fix (see below) but then it shows a problem on the
host side when using with g_zero (see further below):
commit 3b8932100aacb6cfbffe288ca93025d8b8430c00
Author: Felipe Balbi
Date: Wed Aug 19 18:05:27 2015 -0500
usb: gadget: fix ep->claimed lifetime
In order to fix a regression introduced by commit
cc476b42a39d ("usb: gadget: encapsulate endpoint
claiming mechanism") we have to introduce a simple
helper to check if a particular is enabled or not.
After that, we need to move ep->claimed lifetime to
usb_ep_enable() and usb_ep_disable() since those
are the only functions which actually enable and
disable endpoints.
A follow-up patch will come to drop all driver_data
checks from function drivers, since those are, now,
pointless.
Fixes: cc476b42a39d ("usb: gadget: encapsulate endpoint
claiming mechanism")
Cc: Robert Baldyga
Signed-off-by: Felipe Balbi
diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 978435a51038..ad45070cd76f 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -126,7 +126,6 @@ found_ep:
ep->address = desc->bEndpointAddress;
ep->desc = NULL;
ep->comp_desc = NULL;
- ep->claimed = true;
Removing this line causes autoconfig can return the same endpoint many
times. This probably causes problems with g_zero.
I will try to fix it ASAP.
I was considering the same thing, but the lifetime of ->claimed doesn't
look correct to me either way. Note that once the flag is enabled, it
won't get disabled by most gadget drivers.
And it should not be. This flag is indicator, that endpoint is used by
some function. It should be set once by usb_ep_autoconfig() and cleared
by usb_ep_autoconfig_reset().
I wonder what is reason of this enable/disable regression. Maybe the
problem is that we don't set ep->driver_data to NULL in
usb_ep_autoconfig_reset() (so far it was done). Does this problem occur
while gadget is binded to UDC for the first time, or at any next time?
Unfortunately at this moment I don't have access to my hardware, so it
will take a moment before I will setup some testing environment.
Thanks,
Robert
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Re: [PATCH v5 01/46] usb: gadget: encapsulate endpoint claiming mechanism
On Thu, Aug 20, 2015 at 06:28:14PM +0200, Robert Baldyga wrote:
> Hi Felipe,
>
> On 08/20/2015 05:35 PM, Felipe Balbi wrote:
> [...]
> >just letting you know that this regresses all gadget drivers making them
> >try to disable previously disabled endpoints and enable previously
> >enabled endpoints.
> >
> >I have a possible fix (see below) but then it shows a problem on the
> >host side when using with g_zero (see further below):
> >
> >commit 3b8932100aacb6cfbffe288ca93025d8b8430c00
> >Author: Felipe Balbi
> >Date: Wed Aug 19 18:05:27 2015 -0500
> >
> > usb: gadget: fix ep->claimed lifetime
> >
> > In order to fix a regression introduced by commit
> > cc476b42a39d ("usb: gadget: encapsulate endpoint
> > claiming mechanism") we have to introduce a simple
> > helper to check if a particular is enabled or not.
> >
> > After that, we need to move ep->claimed lifetime to
> > usb_ep_enable() and usb_ep_disable() since those
> > are the only functions which actually enable and
> > disable endpoints.
> >
> > A follow-up patch will come to drop all driver_data
> > checks from function drivers, since those are, now,
> > pointless.
> >
> > Fixes: cc476b42a39d ("usb: gadget: encapsulate endpoint
> > claiming mechanism")
> > Cc: Robert Baldyga
> > Signed-off-by: Felipe Balbi
> >
> >diff --git a/drivers/usb/gadget/epautoconf.c
> >b/drivers/usb/gadget/epautoconf.c
> >index 978435a51038..ad45070cd76f 100644
> >--- a/drivers/usb/gadget/epautoconf.c
> >+++ b/drivers/usb/gadget/epautoconf.c
> >@@ -126,7 +126,6 @@ found_ep:
> > ep->address = desc->bEndpointAddress;
> > ep->desc = NULL;
> > ep->comp_desc = NULL;
> >-ep->claimed = true;
>
> Removing this line causes autoconfig can return the same endpoint many
> times. This probably causes problems with g_zero.
>
> I will try to fix it ASAP.
I was considering the same thing, but the lifetime of ->claimed doesn't
look correct to me either way. Note that once the flag is enabled, it
won't get disabled by most gadget drivers.
--
balbi
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Re: [PATCH v5 01/46] usb: gadget: encapsulate endpoint claiming mechanism
Hi Felipe,
On 08/20/2015 05:35 PM, Felipe Balbi wrote:
[...]
just letting you know that this regresses all gadget drivers making them
try to disable previously disabled endpoints and enable previously
enabled endpoints.
I have a possible fix (see below) but then it shows a problem on the
host side when using with g_zero (see further below):
commit 3b8932100aacb6cfbffe288ca93025d8b8430c00
Author: Felipe Balbi
Date: Wed Aug 19 18:05:27 2015 -0500
usb: gadget: fix ep->claimed lifetime
In order to fix a regression introduced by commit
cc476b42a39d ("usb: gadget: encapsulate endpoint
claiming mechanism") we have to introduce a simple
helper to check if a particular is enabled or not.
After that, we need to move ep->claimed lifetime to
usb_ep_enable() and usb_ep_disable() since those
are the only functions which actually enable and
disable endpoints.
A follow-up patch will come to drop all driver_data
checks from function drivers, since those are, now,
pointless.
Fixes: cc476b42a39d ("usb: gadget: encapsulate endpoint
claiming mechanism")
Cc: Robert Baldyga
Signed-off-by: Felipe Balbi
diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 978435a51038..ad45070cd76f 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -126,7 +126,6 @@ found_ep:
ep->address = desc->bEndpointAddress;
ep->desc = NULL;
ep->comp_desc = NULL;
- ep->claimed = true;
Removing this line causes autoconfig can return the same endpoint many
times. This probably causes problems with g_zero.
I will try to fix it ASAP.
Thanks,
Robert
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Re: [PATCH v5 01/46] usb: gadget: encapsulate endpoint claiming mechanism
Hi,
On Fri, Jul 31, 2015 at 04:00:13PM +0200, Robert Baldyga wrote:
> So far it was necessary for usb functions to set ep->driver_data in
> endpoint obtained from autoconfig to non-null value, to indicate that
> endpoint is claimed by function (in autoconfig it was checked if endpoint
> has set this field to non-null value, and if it has, it was assumed that
> it is claimed). It could cause bugs because if some function doesn't
> set this field autoconfig could return the same endpoint more than one
> time.
>
> To help to avoid such bugs this patch adds claimed flag to struct usb_ep,
> and encapsulates endpoint claiming mechanism inside usb_ep_autoconfig_ss()
> and usb_ep_autoconfig_reset(), so now usb functions don't need to perform
> any additional actions to mark endpoint obtained from autoconfig as claimed.
>
> Signed-off-by: Robert Baldyga
just letting you know that this regresses all gadget drivers making them
try to disable previously disabled endpoints and enable previously
enabled endpoints.
I have a possible fix (see below) but then it shows a problem on the
host side when using with g_zero (see further below):
commit 3b8932100aacb6cfbffe288ca93025d8b8430c00
Author: Felipe Balbi
Date: Wed Aug 19 18:05:27 2015 -0500
usb: gadget: fix ep->claimed lifetime
In order to fix a regression introduced by commit
cc476b42a39d ("usb: gadget: encapsulate endpoint
claiming mechanism") we have to introduce a simple
helper to check if a particular is enabled or not.
After that, we need to move ep->claimed lifetime to
usb_ep_enable() and usb_ep_disable() since those
are the only functions which actually enable and
disable endpoints.
A follow-up patch will come to drop all driver_data
checks from function drivers, since those are, now,
pointless.
Fixes: cc476b42a39d ("usb: gadget: encapsulate endpoint
claiming mechanism")
Cc: Robert Baldyga
Signed-off-by: Felipe Balbi
diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 978435a51038..ad45070cd76f 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -126,7 +126,6 @@ found_ep:
ep->address = desc->bEndpointAddress;
ep->desc = NULL;
ep->comp_desc = NULL;
- ep->claimed = true;
return ep;
}
EXPORT_SYMBOL_GPL(usb_ep_autoconfig_ss);
@@ -182,11 +181,6 @@ EXPORT_SYMBOL_GPL(usb_ep_autoconfig);
*/
void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
{
- struct usb_ep *ep;
-
- list_for_each_entry (ep, &gadget->ep_list, ep_list) {
- ep->claimed = false;
- }
gadget->in_epnum = 0;
gadget->out_epnum = 0;
}
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index c14a69b36d27..9b3d60c1cf9f 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -243,6 +243,22 @@ static inline void usb_ep_set_maxpacket_limit(struct
usb_ep *ep,
}
/**
+ * usb_ep_enabled - is endpoint enabled ?
+ * @ep: the endpoint being checked. may not be the endpoint named "ep0".
+ *
+ * Whenever a function driver wants to check if a particular endpoint is
+ * enabled or not, it must check using this helper function. This will
+ * encapsulate details about how the endpoint is checked, saving the function
+ * driver from using private methods for doing so.
+ *
+ * return true if endpoint is enabled, false otherwise.
+ */
+static inline bool usb_ep_enabled(struct usb_ep *ep)
+{
+ return ep->claimed;
+}
+
+/**
* usb_ep_enable - configure endpoint, making it usable
* @ep:the endpoint being configured. may not be the endpoint named "ep0".
* drivers discover endpoints through the ep_list of a usb_gadget.
@@ -264,7 +280,18 @@ static inline void usb_ep_set_maxpacket_limit(struct
usb_ep *ep,
*/
static inline int usb_ep_enable(struct usb_ep *ep)
{
- return ep->ops->enable(ep, ep->desc);
+ int ret;
+
+ if (usb_ep_enabled(ep))
+ return 0;
+
+ ret = ep->ops->enable(ep, ep->desc);
+ if (ret)
+ return ret;
+
+ ep->claimed = true;
+
+ return 0;
}
/**
@@ -281,7 +308,18 @@ static inline int usb_ep_enable(struct usb_ep *ep)
*/
static inline int usb_ep_disable(struct usb_ep *ep)
{
- return ep->ops->disable(ep);
+ int ret;
+
+ if (!usb_ep_enabled(ep))
+ return 0;
+
+ ret = ep->ops->disable(ep);
+ if (ret)
+ return ret;
+
+ ep->claimed = false;
+
+ return 0;
}
/**
[ 73.290345] WARNING: CPU: 0 PID: 300 at lib/kobject.c:240
kobject_add_internal+0x25c/0x2d8()
[ 73.299172] kobject_add_internal failed for ep_81 with -EEXIST, don't try to
register things with the same name in the same directory.
[ 73.311825] Modules linked in: usbtest usb_f_ss_lb g_zero libcomposite
xhci_plat_hcd xhci_hcd usbcore joydev dwc3 udc_core usb_common m25p80 evdev
spi_nor omapfb
[PATCH v5 01/46] usb: gadget: encapsulate endpoint claiming mechanism
So far it was necessary for usb functions to set ep->driver_data in
endpoint obtained from autoconfig to non-null value, to indicate that
endpoint is claimed by function (in autoconfig it was checked if endpoint
has set this field to non-null value, and if it has, it was assumed that
it is claimed). It could cause bugs because if some function doesn't
set this field autoconfig could return the same endpoint more than one
time.
To help to avoid such bugs this patch adds claimed flag to struct usb_ep,
and encapsulates endpoint claiming mechanism inside usb_ep_autoconfig_ss()
and usb_ep_autoconfig_reset(), so now usb functions don't need to perform
any additional actions to mark endpoint obtained from autoconfig as claimed.
Signed-off-by: Robert Baldyga
---
drivers/usb/gadget/epautoconf.c | 11 ++-
include/linux/usb/gadget.h | 1 +
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
index 919cdfd..8e00ca7 100644
--- a/drivers/usb/gadget/epautoconf.c
+++ b/drivers/usb/gadget/epautoconf.c
@@ -53,7 +53,7 @@ ep_matches (
int num_req_streams = 0;
/* endpoint already claimed? */
- if (NULL != ep->driver_data)
+ if (ep->claimed)
return 0;
/* only support ep0 for portable CONTROL traffic */
@@ -240,7 +240,7 @@ find_ep (struct usb_gadget *gadget, const char *name)
* updated with the assigned number of streams if it is
* different from the original value. To prevent the endpoint
* from being returned by a later autoconfig call, claim it by
- * assigning ep->driver_data to some non-null value.
+ * assigning ep->claimed to true.
*
* On failure, this returns a null endpoint descriptor.
*/
@@ -323,6 +323,7 @@ struct usb_ep *usb_ep_autoconfig_ss(
found_ep:
ep->desc = NULL;
ep->comp_desc = NULL;
+ ep->claimed = true;
return ep;
}
EXPORT_SYMBOL_GPL(usb_ep_autoconfig_ss);
@@ -354,7 +355,7 @@ EXPORT_SYMBOL_GPL(usb_ep_autoconfig_ss);
* descriptor bEndpointAddress. For bulk endpoints, the wMaxPacket value
* is initialized as if the endpoint were used at full speed. To prevent
* the endpoint from being returned by a later autoconfig call, claim it
- * by assigning ep->driver_data to some non-null value.
+ * by assigning ep->claimed to true.
*
* On failure, this returns a null endpoint descriptor.
*/
@@ -373,7 +374,7 @@ EXPORT_SYMBOL_GPL(usb_ep_autoconfig);
*
* Use this for devices where one configuration may need to assign
* endpoint resources very differently from the next one. It clears
- * state such as ep->driver_data and the record of assigned endpoints
+ * state such as ep->claimed and the record of assigned endpoints
* used by usb_ep_autoconfig().
*/
void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
@@ -381,7 +382,7 @@ void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
struct usb_ep *ep;
list_for_each_entry (ep, &gadget->ep_list, ep_list) {
- ep->driver_data = NULL;
+ ep->claimed = false;
}
gadget->in_epnum = 0;
gadget->out_epnum = 0;
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 353a720..68fb5e8 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -173,6 +173,7 @@ struct usb_ep {
const char *name;
const struct usb_ep_ops *ops;
struct list_headep_list;
+ boolclaimed;
unsignedmaxpacket:16;
unsignedmaxpacket_limit:16;
unsignedmax_streams:16;
--
1.9.1
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