[PATCH] isp1362-hcd.c: usb message always saved in case of underrun

[PATCH] isp1362-hcd.c: usb message always saved in case of underrun

[Claudio Scordino]

Hi Olav,

	please find below a patch for the isp1362-hcd.c driver to always
save the message in case of underrun. More information is provided
inside the patch comment. Let us know if you need any further
information.

Best regards,

	Claudio


Subject: isp1362-hcd.c: usb message always saved in case of underrun
From: Bruno Morelli <bruno@evidence.eu.com>

The usb message must be saved also in case the USB endpoint is not a
control endpoint (i.e., "endpoint 0"), otherwise in some circumstances
we don't have a payload in case of error.

The patch has been created by tracing with usbmon the different error
messages generated by this driver with respect to the ehci-hcd driver.

Signed-off-by: Bruno Morelli <bruno@evidence.eu.com>
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Tested-by: Bruno Morelli <bruno@evidence.eu.com>
---
  drivers/usb/host/isp1362-hcd.c |   11 ++++++-----
  1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
index 2ed112d..61bf1b2 100644
--- a/drivers/usb/host/isp1362-hcd.c
+++ b/drivers/usb/host/isp1362-hcd.c
@@ -543,13 +543,14 @@ static void postproc_ep(struct isp1362_hcd *isp1362_hcd, struct isp1362_ep *ep)
  			    usb_pipein(urb->pipe) ? "IN" : "OUT", ep->nextpid,
  			    short_ok ? "" : "not_",
  			    PTD_GET_COUNT(ptd), ep->maxpacket, len);
+			/* save the data underrun error code for later and
+			 * proceed with the status stage
+			 */
+			urb->actual_length += PTD_GET_COUNT(ptd);
+			BUG_ON(urb->actual_length >
+			    urb->transfer_buffer_length);
  			if (usb_pipecontrol(urb->pipe)) {
  				ep->nextpid = USB_PID_ACK;
-				/* save the data underrun error code for later and
-				 * proceed with the status stage
-				 */
-				urb->actual_length += PTD_GET_COUNT(ptd);
-				BUG_ON(urb->actual_length > urb->transfer_buffer_length);
  
  				if (urb->status == -EINPROGRESS)
  					urb->status = cc_to_error[PTD_DATAUNDERRUN];
-- 
1.7.1

Re: [PATCH] isp1362-hcd.c: usb message always saved in case of underrun

[Greg KH]

On Wed, Jun 27, 2012 at 06:01:39PM +0200, Claudio Scordino wrote:
> Hi Olav,
> 
> 	please find below a patch for the isp1362-hcd.c driver to always
> save the message in case of underrun. More information is provided
> inside the patch comment. Let us know if you need any further
> information.
> 
> Best regards,
> 
> 	Claudio
> 
> 
> Subject: isp1362-hcd.c: usb message always saved in case of underrun
> From: Bruno Morelli <bruno@evidence.eu.com>
> 
> The usb message must be saved also in case the USB endpoint is not a
> control endpoint (i.e., "endpoint 0"), otherwise in some circumstances
> we don't have a payload in case of error.
> 
> The patch has been created by tracing with usbmon the different error
> messages generated by this driver with respect to the ehci-hcd driver.
> 
> Signed-off-by: Bruno Morelli <bruno@evidence.eu.com>
> Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
> Tested-by: Bruno Morelli <bruno@evidence.eu.com>
> ---
>  drivers/usb/host/isp1362-hcd.c |   11 ++++++-----
>  1 files changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
> index 2ed112d..61bf1b2 100644
> --- a/drivers/usb/host/isp1362-hcd.c
> +++ b/drivers/usb/host/isp1362-hcd.c
> @@ -543,13 +543,14 @@ static void postproc_ep(struct isp1362_hcd *isp1362_hcd, struct isp1362_ep *ep)
>  			    usb_pipein(urb->pipe) ? "IN" : "OUT", ep->nextpid,
>  			    short_ok ? "" : "not_",
>  			    PTD_GET_COUNT(ptd), ep->maxpacket, len);
> +			/* save the data underrun error code for later and
> +			 * proceed with the status stage
> +			 */
> +			urb->actual_length += PTD_GET_COUNT(ptd);
> +			BUG_ON(urb->actual_length >
> +			    urb->transfer_buffer_length);

Please NEVER crash the machine in a driver like this, it's bad and can
cause problems.  Yes, I know you are just moving it from the lines
below:

>  			if (usb_pipecontrol(urb->pipe)) {
>  				ep->nextpid = USB_PID_ACK;
> -				/* save the data underrun error code for later and
> -				 * proceed with the status stage
> -				 */
> -				urb->actual_length += PTD_GET_COUNT(ptd);
> -				BUG_ON(urb->actual_length > urb->transfer_buffer_length);

But really, it should not be in the driver at all.  Please remove it, at
the most, do a WARN_ON() so that someone can see the problem and at
least report it.

Actually, what is this checking?  How can someone recover from it?  Who
is this check for?  The developer of this driver?  Another driver?
Hardware developer?  End user?  Who would be able to fix the problem if
this happens?

As it is, I can't take it, sorry.

greg k-h

Re: [PATCH] isp1362-hcd.c: usb message always saved in case of underrun

[Claudio Scordino]

Il 06/07/2012 19:41, Greg KH ha scritto:
> On Wed, Jun 27, 2012 at 06:01:39PM +0200, Claudio Scordino wrote:
>> Hi Olav,
>>
>> 	please find below a patch for the isp1362-hcd.c driver to always
>> save the message in case of underrun. More information is provided
>> inside the patch comment. Let us know if you need any further
>> information.
>>
>> Best regards,
>>
>> 	Claudio
>>
>>
>> Subject: isp1362-hcd.c: usb message always saved in case of underrun
>> From: Bruno Morelli<bruno@evidence.eu.com>
>>
>> The usb message must be saved also in case the USB endpoint is not a
>> control endpoint (i.e., "endpoint 0"), otherwise in some circumstances
>> we don't have a payload in case of error.
>>
>> The patch has been created by tracing with usbmon the different error
>> messages generated by this driver with respect to the ehci-hcd driver.
>>
>> Signed-off-by: Bruno Morelli<bruno@evidence.eu.com>
>> Signed-off-by: Claudio Scordino<claudio@evidence.eu.com>
>> Tested-by: Bruno Morelli<bruno@evidence.eu.com>
>> ---
>>   drivers/usb/host/isp1362-hcd.c |   11 ++++++-----
>>   1 files changed, 6 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
>> index 2ed112d..61bf1b2 100644
>> --- a/drivers/usb/host/isp1362-hcd.c
>> +++ b/drivers/usb/host/isp1362-hcd.c
>> @@ -543,13 +543,14 @@ static void postproc_ep(struct isp1362_hcd *isp1362_hcd, struct isp1362_ep *ep)
>>   			    usb_pipein(urb->pipe) ? "IN" : "OUT", ep->nextpid,
>>   			    short_ok ? "" : "not_",
>>   			    PTD_GET_COUNT(ptd), ep->maxpacket, len);
>> +			/* save the data underrun error code for later and
>> +			 * proceed with the status stage
>> +			 */
>> +			urb->actual_length += PTD_GET_COUNT(ptd);
>> +			BUG_ON(urb->actual_length>
>> +			    urb->transfer_buffer_length);
>
> Please NEVER crash the machine in a driver like this, it's bad and can
> cause problems.  Yes, I know you are just moving it from the lines
> below:
>
>>   			if (usb_pipecontrol(urb->pipe)) {
>>   				ep->nextpid = USB_PID_ACK;
>> -				/* save the data underrun error code for later and
>> -				 * proceed with the status stage
>> -				 */
>> -				urb->actual_length += PTD_GET_COUNT(ptd);
>> -				BUG_ON(urb->actual_length>  urb->transfer_buffer_length);
>
> But really, it should not be in the driver at all.  Please remove it, at
> the most, do a WARN_ON() so that someone can see the problem and at
> least report it.
>
> Actually, what is this checking?  How can someone recover from it?  Who
> is this check for?  The developer of this driver?  Another driver?
> Hardware developer?  End user?  Who would be able to fix the problem if
> this happens?
>
> As it is, I can't take it, sorry.


Hi Greg.

I understand. As you have already said, this driver is full of BUG_ON
statements.

So, we can shift just the assignment as in the patch below, to have a
correct behavior, leaving the BUG_ON where it already is. Then, we may
propose a different patch to change BUG_ONs to WARN_ONs.

Best regards,

            Claudio


Subject: isp1362-hcd.c: usb message always saved in case of underrun
From: Bruno Morelli <bruno@evidence.eu.com>

The usb message must be saved also in case the USB endpoint is not a control
endpoint (i.e., "endpoint 0"), otherwise in some circumstances we don't have a
payload in case of error.

The patch has been created by tracing with usbmon the different error messages
generated by this driver with respect to the ehci-hcd driver.

Signed-off-by: Bruno Morelli <bruno@evidence.eu.com>
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Tested-by: Bruno Morelli <bruno@evidence.eu.com>
---
  drivers/usb/host/isp1362-hcd.c |    8 ++++----
  1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
index 2ed112d..2563263 100644
--- a/drivers/usb/host/isp1362-hcd.c
+++ b/drivers/usb/host/isp1362-hcd.c
@@ -543,12 +543,12 @@ static void postproc_ep(struct isp1362_hcd *isp1362_hcd, struct isp1362_ep *ep)
  			    usb_pipein(urb->pipe) ? "IN" : "OUT", ep->nextpid,
  			    short_ok ? "" : "not_",
  			    PTD_GET_COUNT(ptd), ep->maxpacket, len);
+			/* save the data underrun error code for later and
+			 * proceed with the status stage
+			 */
+			urb->actual_length += PTD_GET_COUNT(ptd);
  			if (usb_pipecontrol(urb->pipe)) {
  				ep->nextpid = USB_PID_ACK;
-				/* save the data underrun error code for later and
-				 * proceed with the status stage
-				 */
-				urb->actual_length += PTD_GET_COUNT(ptd);
  				BUG_ON(urb->actual_length > urb->transfer_buffer_length);
  
  				if (urb->status == -EINPROGRESS)
-- 
1.7.1

Re: [PATCH] isp1362-hcd.c: usb message always saved in case of underrun

[Greg KH]

On Wed, Jul 18, 2012 at 10:53:09AM +0200, Claudio Scordino wrote:
> Il 06/07/2012 19:41, Greg KH ha scritto:
> >On Wed, Jun 27, 2012 at 06:01:39PM +0200, Claudio Scordino wrote:
> >>Hi Olav,
> >>
> >>	please find below a patch for the isp1362-hcd.c driver to always
> >>save the message in case of underrun. More information is provided
> >>inside the patch comment. Let us know if you need any further
> >>information.
> >>
> >>Best regards,
> >>
> >>	Claudio
> >>
> >>
> >>Subject: isp1362-hcd.c: usb message always saved in case of underrun
> >>From: Bruno Morelli<bruno@evidence.eu.com>
> >>
> >>The usb message must be saved also in case the USB endpoint is not a
> >>control endpoint (i.e., "endpoint 0"), otherwise in some circumstances
> >>we don't have a payload in case of error.
> >>
> >>The patch has been created by tracing with usbmon the different error
> >>messages generated by this driver with respect to the ehci-hcd driver.
> >>
> >>Signed-off-by: Bruno Morelli<bruno@evidence.eu.com>
> >>Signed-off-by: Claudio Scordino<claudio@evidence.eu.com>
> >>Tested-by: Bruno Morelli<bruno@evidence.eu.com>
> >>---
> >>  drivers/usb/host/isp1362-hcd.c |   11 ++++++-----
> >>  1 files changed, 6 insertions(+), 5 deletions(-)
> >>
> >>diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
> >>index 2ed112d..61bf1b2 100644
> >>--- a/drivers/usb/host/isp1362-hcd.c
> >>+++ b/drivers/usb/host/isp1362-hcd.c
> >>@@ -543,13 +543,14 @@ static void postproc_ep(struct isp1362_hcd *isp1362_hcd, struct isp1362_ep *ep)
> >>  			    usb_pipein(urb->pipe) ? "IN" : "OUT", ep->nextpid,
> >>  			    short_ok ? "" : "not_",
> >>  			    PTD_GET_COUNT(ptd), ep->maxpacket, len);
> >>+			/* save the data underrun error code for later and
> >>+			 * proceed with the status stage
> >>+			 */
> >>+			urb->actual_length += PTD_GET_COUNT(ptd);
> >>+			BUG_ON(urb->actual_length>
> >>+			    urb->transfer_buffer_length);
> >
> >Please NEVER crash the machine in a driver like this, it's bad and can
> >cause problems.  Yes, I know you are just moving it from the lines
> >below:
> >
> >>  			if (usb_pipecontrol(urb->pipe)) {
> >>  				ep->nextpid = USB_PID_ACK;
> >>-				/* save the data underrun error code for later and
> >>-				 * proceed with the status stage
> >>-				 */
> >>-				urb->actual_length += PTD_GET_COUNT(ptd);
> >>-				BUG_ON(urb->actual_length>  urb->transfer_buffer_length);
> >
> >But really, it should not be in the driver at all.  Please remove it, at
> >the most, do a WARN_ON() so that someone can see the problem and at
> >least report it.
> >
> >Actually, what is this checking?  How can someone recover from it?  Who
> >is this check for?  The developer of this driver?  Another driver?
> >Hardware developer?  End user?  Who would be able to fix the problem if
> >this happens?
> >
> >As it is, I can't take it, sorry.
> 
> 
> Hi Greg.
> 
> I understand. As you have already said, this driver is full of BUG_ON
> statements.
> 
> So, we can shift just the assignment as in the patch below, to have a
> correct behavior, leaving the BUG_ON where it already is. Then, we may
> propose a different patch to change BUG_ONs to WARN_ONs.

Your updated patch is much better, thanks.

But it doesn't apply to my tree right now.  Can you please refresh it
against the usb-next tree and resend it?

thanks,

greg k-h

Re: [PATCH] isp1362-hcd.c: usb message always saved in case of underrun

[Claudio Scordino]

Il 20/07/2012 00:58, Greg KH ha scritto:
> On Wed, Jul 18, 2012 at 10:53:09AM +0200, Claudio Scordino wrote:
>> Il 06/07/2012 19:41, Greg KH ha scritto:
>>> On Wed, Jun 27, 2012 at 06:01:39PM +0200, Claudio Scordino wrote:
>>>> Hi Olav,
>>>>
>>>> 	please find below a patch for the isp1362-hcd.c driver to always
>>>> save the message in case of underrun. More information is provided
>>>> inside the patch comment. Let us know if you need any further
>>>> information.
>>>>
>>>> Best regards,
>>>>
>>>> 	Claudio
>>>>
>>>>
>>>> Subject: isp1362-hcd.c: usb message always saved in case of underrun
>>>> From: Bruno Morelli<bruno@evidence.eu.com>
>>>>
>>>> The usb message must be saved also in case the USB endpoint is not a
>>>> control endpoint (i.e., "endpoint 0"), otherwise in some circumstances
>>>> we don't have a payload in case of error.
>>>>
>>>> The patch has been created by tracing with usbmon the different error
>>>> messages generated by this driver with respect to the ehci-hcd driver.
>>>>
>>>> Signed-off-by: Bruno Morelli<bruno@evidence.eu.com>
>>>> Signed-off-by: Claudio Scordino<claudio@evidence.eu.com>
>>>> Tested-by: Bruno Morelli<bruno@evidence.eu.com>
>>>> ---
>>>>   drivers/usb/host/isp1362-hcd.c |   11 ++++++-----
>>>>   1 files changed, 6 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
>>>> index 2ed112d..61bf1b2 100644
>>>> --- a/drivers/usb/host/isp1362-hcd.c
>>>> +++ b/drivers/usb/host/isp1362-hcd.c
>>>> @@ -543,13 +543,14 @@ static void postproc_ep(struct isp1362_hcd *isp1362_hcd, struct isp1362_ep *ep)
>>>>   			    usb_pipein(urb->pipe) ? "IN" : "OUT", ep->nextpid,
>>>>   			    short_ok ? "" : "not_",
>>>>   			    PTD_GET_COUNT(ptd), ep->maxpacket, len);
>>>> +			/* save the data underrun error code for later and
>>>> +			 * proceed with the status stage
>>>> +			 */
>>>> +			urb->actual_length += PTD_GET_COUNT(ptd);
>>>> +			BUG_ON(urb->actual_length>
>>>> +			    urb->transfer_buffer_length);
>>>
>>> Please NEVER crash the machine in a driver like this, it's bad and can
>>> cause problems.  Yes, I know you are just moving it from the lines
>>> below:
>>>
>>>>   			if (usb_pipecontrol(urb->pipe)) {
>>>>   				ep->nextpid = USB_PID_ACK;
>>>> -				/* save the data underrun error code for later and
>>>> -				 * proceed with the status stage
>>>> -				 */
>>>> -				urb->actual_length += PTD_GET_COUNT(ptd);
>>>> -				BUG_ON(urb->actual_length>   urb->transfer_buffer_length);
>>>
>>> But really, it should not be in the driver at all.  Please remove it, at
>>> the most, do a WARN_ON() so that someone can see the problem and at
>>> least report it.
>>>
>>> Actually, what is this checking?  How can someone recover from it?  Who
>>> is this check for?  The developer of this driver?  Another driver?
>>> Hardware developer?  End user?  Who would be able to fix the problem if
>>> this happens?
>>>
>>> As it is, I can't take it, sorry.
>>
>>
>> Hi Greg.
>>
>> I understand. As you have already said, this driver is full of BUG_ON
>> statements.
>>
>> So, we can shift just the assignment as in the patch below, to have a
>> correct behavior, leaving the BUG_ON where it already is. Then, we may
>> propose a different patch to change BUG_ONs to WARN_ONs.
>
> Your updated patch is much better, thanks.
>
> But it doesn't apply to my tree right now.  Can you please refresh it
> against the usb-next tree and resend it?

Actually, I did.

So, this means that I'm using the wrong tree...

I'm using the "usb-next" branch available on your tree at

	git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git

Is this the wrong one ?

Many thanks,

	Claudio

Re: [PATCH] isp1362-hcd.c: usb message always saved in case of underrun

[Greg KH]

On Fri, Jul 20, 2012 at 12:26:10PM +0200, Claudio Scordino wrote:
> Il 20/07/2012 00:58, Greg KH ha scritto:
> >On Wed, Jul 18, 2012 at 10:53:09AM +0200, Claudio Scordino wrote:
> >>Il 06/07/2012 19:41, Greg KH ha scritto:
> >>>On Wed, Jun 27, 2012 at 06:01:39PM +0200, Claudio Scordino wrote:
> >>>>Hi Olav,
> >>>>
> >>>>	please find below a patch for the isp1362-hcd.c driver to always
> >>>>save the message in case of underrun. More information is provided
> >>>>inside the patch comment. Let us know if you need any further
> >>>>information.
> >>>>
> >>>>Best regards,
> >>>>
> >>>>	Claudio
> >>>>
> >>>>
> >>>>Subject: isp1362-hcd.c: usb message always saved in case of underrun
> >>>>From: Bruno Morelli<bruno@evidence.eu.com>
> >>>>
> >>>>The usb message must be saved also in case the USB endpoint is not a
> >>>>control endpoint (i.e., "endpoint 0"), otherwise in some circumstances
> >>>>we don't have a payload in case of error.
> >>>>
> >>>>The patch has been created by tracing with usbmon the different error
> >>>>messages generated by this driver with respect to the ehci-hcd driver.
> >>>>
> >>>>Signed-off-by: Bruno Morelli<bruno@evidence.eu.com>
> >>>>Signed-off-by: Claudio Scordino<claudio@evidence.eu.com>
> >>>>Tested-by: Bruno Morelli<bruno@evidence.eu.com>
> >>>>---
> >>>>  drivers/usb/host/isp1362-hcd.c |   11 ++++++-----
> >>>>  1 files changed, 6 insertions(+), 5 deletions(-)
> >>>>
> >>>>diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
> >>>>index 2ed112d..61bf1b2 100644
> >>>>--- a/drivers/usb/host/isp1362-hcd.c
> >>>>+++ b/drivers/usb/host/isp1362-hcd.c
> >>>>@@ -543,13 +543,14 @@ static void postproc_ep(struct isp1362_hcd *isp1362_hcd, struct isp1362_ep *ep)
> >>>>  			    usb_pipein(urb->pipe) ? "IN" : "OUT", ep->nextpid,
> >>>>  			    short_ok ? "" : "not_",
> >>>>  			    PTD_GET_COUNT(ptd), ep->maxpacket, len);
> >>>>+			/* save the data underrun error code for later and
> >>>>+			 * proceed with the status stage
> >>>>+			 */
> >>>>+			urb->actual_length += PTD_GET_COUNT(ptd);
> >>>>+			BUG_ON(urb->actual_length>
> >>>>+			    urb->transfer_buffer_length);
> >>>
> >>>Please NEVER crash the machine in a driver like this, it's bad and can
> >>>cause problems.  Yes, I know you are just moving it from the lines
> >>>below:
> >>>
> >>>>  			if (usb_pipecontrol(urb->pipe)) {
> >>>>  				ep->nextpid = USB_PID_ACK;
> >>>>-				/* save the data underrun error code for later and
> >>>>-				 * proceed with the status stage
> >>>>-				 */
> >>>>-				urb->actual_length += PTD_GET_COUNT(ptd);
> >>>>-				BUG_ON(urb->actual_length>   urb->transfer_buffer_length);
> >>>
> >>>But really, it should not be in the driver at all.  Please remove it, at
> >>>the most, do a WARN_ON() so that someone can see the problem and at
> >>>least report it.
> >>>
> >>>Actually, what is this checking?  How can someone recover from it?  Who
> >>>is this check for?  The developer of this driver?  Another driver?
> >>>Hardware developer?  End user?  Who would be able to fix the problem if
> >>>this happens?
> >>>
> >>>As it is, I can't take it, sorry.
> >>
> >>
> >>Hi Greg.
> >>
> >>I understand. As you have already said, this driver is full of BUG_ON
> >>statements.
> >>
> >>So, we can shift just the assignment as in the patch below, to have a
> >>correct behavior, leaving the BUG_ON where it already is. Then, we may
> >>propose a different patch to change BUG_ONs to WARN_ONs.
> >
> >Your updated patch is much better, thanks.
> >
> >But it doesn't apply to my tree right now.  Can you please refresh it
> >against the usb-next tree and resend it?
> 
> Actually, I did.
> 
> So, this means that I'm using the wrong tree...
> 
> I'm using the "usb-next" branch available on your tree at
> 
> 	git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
> 
> Is this the wrong one ?

That is the correct one.  It didn't work for me, so try refreshing your
patch and resending it.

thanks,

greg k-h

Re: [PATCH] isp1362-hcd.c: usb message always saved in case of underrun

[Claudio Scordino]

Il 20/07/2012 17:15, Greg KH ha scritto:
> On Fri, Jul 20, 2012 at 12:26:10PM +0200, Claudio Scordino wrote:
>> Il 20/07/2012 00:58, Greg KH ha scritto:
>>> On Wed, Jul 18, 2012 at 10:53:09AM +0200, Claudio Scordino wrote:
>>>> Il 06/07/2012 19:41, Greg KH ha scritto:
>>>>> On Wed, Jun 27, 2012 at 06:01:39PM +0200, Claudio Scordino wrote:
>>>>>> Hi Olav,
>>>>>>
>>>>>> 	please find below a patch for the isp1362-hcd.c driver to always
>>>>>> save the message in case of underrun. More information is provided
>>>>>> inside the patch comment. Let us know if you need any further
>>>>>> information.
>>>>>>
>>>>>> Best regards,
>>>>>>
>>>>>> 	Claudio
>>>>>>
>>>>>>
>>>>>> Subject: isp1362-hcd.c: usb message always saved in case of underrun
>>>>>> From: Bruno Morelli<bruno@evidence.eu.com>
>>>>>>
>>>>>> The usb message must be saved also in case the USB endpoint is not a
>>>>>> control endpoint (i.e., "endpoint 0"), otherwise in some circumstances
>>>>>> we don't have a payload in case of error.
>>>>>>
>>>>>> The patch has been created by tracing with usbmon the different error
>>>>>> messages generated by this driver with respect to the ehci-hcd driver.
>>>>>>
>>>>>> Signed-off-by: Bruno Morelli<bruno@evidence.eu.com>
>>>>>> Signed-off-by: Claudio Scordino<claudio@evidence.eu.com>
>>>>>> Tested-by: Bruno Morelli<bruno@evidence.eu.com>
>>>>>> ---
>>>>>>   drivers/usb/host/isp1362-hcd.c |   11 ++++++-----
>>>>>>   1 files changed, 6 insertions(+), 5 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
>>>>>> index 2ed112d..61bf1b2 100644
>>>>>> --- a/drivers/usb/host/isp1362-hcd.c
>>>>>> +++ b/drivers/usb/host/isp1362-hcd.c
>>>>>> @@ -543,13 +543,14 @@ static void postproc_ep(struct isp1362_hcd *isp1362_hcd, struct isp1362_ep *ep)
>>>>>>   			    usb_pipein(urb->pipe) ? "IN" : "OUT", ep->nextpid,
>>>>>>   			    short_ok ? "" : "not_",
>>>>>>   			    PTD_GET_COUNT(ptd), ep->maxpacket, len);
>>>>>> +			/* save the data underrun error code for later and
>>>>>> +			 * proceed with the status stage
>>>>>> +			 */
>>>>>> +			urb->actual_length += PTD_GET_COUNT(ptd);
>>>>>> +			BUG_ON(urb->actual_length>
>>>>>> +			    urb->transfer_buffer_length);
>>>>>
>>>>> Please NEVER crash the machine in a driver like this, it's bad and can
>>>>> cause problems.  Yes, I know you are just moving it from the lines
>>>>> below:
>>>>>
>>>>>>   			if (usb_pipecontrol(urb->pipe)) {
>>>>>>   				ep->nextpid = USB_PID_ACK;
>>>>>> -				/* save the data underrun error code for later and
>>>>>> -				 * proceed with the status stage
>>>>>> -				 */
>>>>>> -				urb->actual_length += PTD_GET_COUNT(ptd);
>>>>>> -				BUG_ON(urb->actual_length>    urb->transfer_buffer_length);
>>>>>
>>>>> But really, it should not be in the driver at all.  Please remove it, at
>>>>> the most, do a WARN_ON() so that someone can see the problem and at
>>>>> least report it.
>>>>>
>>>>> Actually, what is this checking?  How can someone recover from it?  Who
>>>>> is this check for?  The developer of this driver?  Another driver?
>>>>> Hardware developer?  End user?  Who would be able to fix the problem if
>>>>> this happens?
>>>>>
>>>>> As it is, I can't take it, sorry.
>>>>
>>>>
>>>> Hi Greg.
>>>>
>>>> I understand. As you have already said, this driver is full of BUG_ON
>>>> statements.
>>>>
>>>> So, we can shift just the assignment as in the patch below, to have a
>>>> correct behavior, leaving the BUG_ON where it already is. Then, we may
>>>> propose a different patch to change BUG_ONs to WARN_ONs.
>>>
>>> Your updated patch is much better, thanks.
>>>
>>> But it doesn't apply to my tree right now.  Can you please refresh it
>>> against the usb-next tree and resend it?
>>
>> Actually, I did.
>>
>> So, this means that I'm using the wrong tree...
>>
>> I'm using the "usb-next" branch available on your tree at
>>
>> 	git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
>>
>> Is this the wrong one ?
>
> That is the correct one.  It didn't work for me, so try refreshing your
> patch and resending it.

Hi Greg.

I've just refreshed the patch by cloning the repo from scratch and
creating the patch against the "usb-next" branch.

You can find the patch below, but the content is still the same.

Can you please check it again ? Is it possible that you have local
changes not yet committed  ?

Many thanks,

	Claudio


Subject: isp1362-hcd.c: usb message always saved in case of underrun
From: Bruno Morelli <bruno@evidence.eu.com>

The usb message must be saved also in case the USB endpoint is not a
control endpoint (i.e., "endpoint 0"), otherwise in some circumstances
we don't have a payload in case of error.

The patch has been created by tracing with usbmon the different error
messages generated by this driver with respect to the ehci-hcd driver.

Signed-off-by: Bruno Morelli <bruno@evidence.eu.com>
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Tested-by: Bruno Morelli <bruno@evidence.eu.com>
---
  drivers/usb/host/isp1362-hcd.c |    8 ++++----
  1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/isp1362-hcd.c b/drivers/usb/host/isp1362-hcd.c
index 2ed112d..2563263 100644
--- a/drivers/usb/host/isp1362-hcd.c
+++ b/drivers/usb/host/isp1362-hcd.c
@@ -543,12 +543,12 @@ static void postproc_ep(struct isp1362_hcd *isp1362_hcd, struct isp1362_ep *ep)
  			    usb_pipein(urb->pipe) ? "IN" : "OUT", ep->nextpid,
  			    short_ok ? "" : "not_",
  			    PTD_GET_COUNT(ptd), ep->maxpacket, len);
+			/* save the data underrun error code for later and
+			 * proceed with the status stage
+			 */
+			urb->actual_length += PTD_GET_COUNT(ptd);
  			if (usb_pipecontrol(urb->pipe)) {
  				ep->nextpid = USB_PID_ACK;
-				/* save the data underrun error code for later and
-				 * proceed with the status stage
-				 */
-				urb->actual_length += PTD_GET_COUNT(ptd);
  				BUG_ON(urb->actual_length > urb->transfer_buffer_length);
  
  				if (urb->status == -EINPROGRESS)
-- 
1.7.1