[PATCHv2] musb_host: fix lockup on rxcsr_h_error

[PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Max Uvarov]

Fix soft lockup when resetting remote device attached
to usb host. Configuration:
pppd -> musb hub -> usb-serial -> gsm modem
When gsm modem resets, musb rolls in incoming rx interrupts
which does not give any time to other application as result
it totally lock ups. Solution is to keep original logic for RXCSR_H_ERROR
and merge RXCSR_DATAERROR and RXCSR_H_ERROR branches to call same code
for setting rx stall with MUSB_RXCSR_H_WZC_BITS.

Signed-off-by: Max Uvarov <muvarov@gmail.com>
---
 v2: use bitwise or for error flags before logical and. (Sergei Shtylyov).

 drivers/usb/musb/musb_host.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index c3d5fc9..2d9aa78 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -1592,14 +1592,12 @@ void musb_host_rx(struct musb *musb, u8 epnum)
 
 		/* stall; record URB status */
 		status = -EPIPE;
+	} else if (rx_csr & (MUSB_RXCSR_DATAERROR | MUSB_RXCSR_H_ERROR)) {
 
-	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
-		dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
-
-		status = -EPROTO;
-		musb_writeb(epio, MUSB_RXINTERVAL, 0);
-
-	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
+		if (rx_csr & MUSB_RXCSR_H_ERROR) {
+			status = -EPROTO;
+			musb_writeb(epio, MUSB_RXINTERVAL, 0);
+		}
 
 		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
 			dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
-- 
1.9.1

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Wed, Apr 27, 2016 at 09:51:58AM +0300, Max Uvarov wrote:
> Fix soft lockup when resetting remote device attached
> to usb host. Configuration:
> pppd -> musb hub -> usb-serial -> gsm modem

I have heard a few reports similar to this symptom, but never been able
to reproduce it on my side.

> When gsm modem resets, musb rolls in incoming rx interrupts
> which does not give any time to other application as result
> it totally lock ups. Solution is to keep original logic for RXCSR_H_ERROR

Have you looked where exact place in the interrupt routine the execution
has stuck in?

> and merge RXCSR_DATAERROR and RXCSR_H_ERROR branches to call same code
> for setting rx stall with MUSB_RXCSR_H_WZC_BITS.

MUSB_RXCSR_H_WZC_BITS itself does not set rx stall, it just ensures
MUSB_RXCSR_H_RXSTALL not to be cleared. Please check its comment in
musb_regs.h.

> 
> Signed-off-by: Max Uvarov <muvarov@gmail.com>
> ---
>  v2: use bitwise or for error flags before logical and. (Sergei Shtylyov).
> 
>  drivers/usb/musb/musb_host.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> index c3d5fc9..2d9aa78 100644
> --- a/drivers/usb/musb/musb_host.c
> +++ b/drivers/usb/musb/musb_host.c
> @@ -1592,14 +1592,12 @@ void musb_host_rx(struct musb *musb, u8 epnum)

What kernel do you use? This line # is away off from upstream kernel.

>  
>  		/* stall; record URB status */
>  		status = -EPIPE;
> +	} else if (rx_csr & (MUSB_RXCSR_DATAERROR | MUSB_RXCSR_H_ERROR)) {
>  
> -	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
> -		dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
> -
> -		status = -EPROTO;
> -		musb_writeb(epio, MUSB_RXINTERVAL, 0);
> -
> -	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> +		if (rx_csr & MUSB_RXCSR_H_ERROR) {
> +			status = -EPROTO;
> +			musb_writeb(epio, MUSB_RXINTERVAL, 0);
> +		}

Please help me to understand how this change fixes the issue. I see the
most effect of the change here is directly 'goto finish' so that 'done'
flag is not set, then musb_advance_schedule() is not called. Is this the
case or I missed other important pieces?

Thanks,
-Bin.

>  
>  		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>  			dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
> -- 
> 1.9.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Maxim Uvarov]

2016-04-27 18:46 GMT+03:00 Bin Liu <b-liu@ti.com>:
> Hi,
>
> On Wed, Apr 27, 2016 at 09:51:58AM +0300, Max Uvarov wrote:
>> Fix soft lockup when resetting remote device attached
>> to usb host. Configuration:
>> pppd -> musb hub -> usb-serial -> gsm modem
>
> I have heard a few reports similar to this symptom, but never been able
> to reproduce it on my side.
>

Ok, I can reproduce it almost very easy.

>> When gsm modem resets, musb rolls in incoming rx interrupts
>> which does not give any time to other application as result
>> it totally lock ups. Solution is to keep original logic for RXCSR_H_ERROR
>
> Have you looked where exact place in the interrupt routine the execution
> has stuck in?
>

It does not stuck. It goes to that line which print proto error over
and over again and
nothing stops that. After some time kernel reports lockup. But
actually it's not stuck,
all cpu time was eaten by executing that handlers.


>> and merge RXCSR_DATAERROR and RXCSR_H_ERROR branches to call same code
>> for setting rx stall with MUSB_RXCSR_H_WZC_BITS.
>
> MUSB_RXCSR_H_WZC_BITS itself does not set rx stall, it just ensures
> MUSB_RXCSR_H_RXSTALL not to be cleared. Please check its comment in
> musb_regs.h.
>
>>
>> Signed-off-by: Max Uvarov <muvarov@gmail.com>
>> ---
>>  v2: use bitwise or for error flags before logical and. (Sergei Shtylyov).
>>
>>  drivers/usb/musb/musb_host.c | 12 +++++-------
>>  1 file changed, 5 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>> index c3d5fc9..2d9aa78 100644
>> --- a/drivers/usb/musb/musb_host.c
>> +++ b/drivers/usb/musb/musb_host.c
>> @@ -1592,14 +1592,12 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>
> What kernel do you use? This line # is away off from upstream kernel.
>

I did this patch for 4.1 but 4.6 has the same problem and patch
cleanly applies to the
latest torvalds/linux.git v4.6-rc5. This interrupt handler has the
same code.  And looks
like on 3.14 everything worked. I don't have a time to diff 2
versions. Might be regression.


>>
>>               /* stall; record URB status */
>>               status = -EPIPE;
>> +     } else if (rx_csr & (MUSB_RXCSR_DATAERROR | MUSB_RXCSR_H_ERROR)) {
>>
>> -     } else if (rx_csr & MUSB_RXCSR_H_ERROR) {
>> -             dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
>> -
>> -             status = -EPROTO;
>> -             musb_writeb(epio, MUSB_RXINTERVAL, 0);
>> -
>> -     } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>> +             if (rx_csr & MUSB_RXCSR_H_ERROR) {
>> +                     status = -EPROTO;
>> +                     musb_writeb(epio, MUSB_RXINTERVAL, 0);
>> +             }
>
> Please help me to understand how this change fixes the issue. I see the
> most effect of the change here is directly 'goto finish' so that 'done'
> flag is not set, then musb_advance_schedule() is not called. Is this the
> case or I missed other important pieces?
>

Right that is the goal. On this rxcsr_h_error kernel reschedules
current interrupt.
And that continues forever. For example adding msleep() can give some
time for other
processes. I'm not an expert in this chip but I think that right
solution in that case is not
try to reschedule and quick and allow hub to make reset and once again
init all devices
(in my case ppp/pppd also shutdowns and then I bring everything up
with script.). The
same behavior with dma and pio mode.

Regards,
Max.

> Thanks,
> -Bin.
>
>>
>>               if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>>                       dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
>> --
>> 1.9.1
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html



-- 
Best regards,
Maxim Uvarov

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Wed, Apr 27, 2016 at 09:26:10PM +0300, Maxim Uvarov wrote:
> 2016-04-27 18:46 GMT+03:00 Bin Liu <b-liu@ti.com>:
> > Hi,
> >
> > On Wed, Apr 27, 2016 at 09:51:58AM +0300, Max Uvarov wrote:
> >> Fix soft lockup when resetting remote device attached
> >> to usb host. Configuration:
> >> pppd -> musb hub -> usb-serial -> gsm modem
> >
> > I have heard a few reports similar to this symptom, but never been able
> > to reproduce it on my side.
> >
> 
> Ok, I can reproduce it almost very easy.
> 
> >> When gsm modem resets, musb rolls in incoming rx interrupts
> >> which does not give any time to other application as result
> >> it totally lock ups. Solution is to keep original logic for RXCSR_H_ERROR
> >
> > Have you looked where exact place in the interrupt routine the execution
> > has stuck in?
> >
> 
> It does not stuck. It goes to that line which print proto error over
> and over again and
> nothing stops that. After some time kernel reports lockup. But
> actually it's not stuck,
> all cpu time was eaten by executing that handlers.
> 
> 
> >> and merge RXCSR_DATAERROR and RXCSR_H_ERROR branches to call same code
> >> for setting rx stall with MUSB_RXCSR_H_WZC_BITS.
> >
> > MUSB_RXCSR_H_WZC_BITS itself does not set rx stall, it just ensures
> > MUSB_RXCSR_H_RXSTALL not to be cleared. Please check its comment in
> > musb_regs.h.
> >
> >>
> >> Signed-off-by: Max Uvarov <muvarov@gmail.com>
> >> ---
> >>  v2: use bitwise or for error flags before logical and. (Sergei Shtylyov).
> >>
> >>  drivers/usb/musb/musb_host.c | 12 +++++-------
> >>  1 file changed, 5 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> >> index c3d5fc9..2d9aa78 100644
> >> --- a/drivers/usb/musb/musb_host.c
> >> +++ b/drivers/usb/musb/musb_host.c
> >> @@ -1592,14 +1592,12 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> >
> > What kernel do you use? This line # is away off from upstream kernel.
> >
> 
> I did this patch for 4.1 but 4.6 has the same problem and patch
> cleanly applies to the latest torvalds/linux.git v4.6-rc5. This
> interrupt handler has the same code.  And looks like on 3.14

Yeah, this code hasn't been chaned for year. But in general, it is
prepfered to create patches on latest kernel to avoid other headache.

> everything worked. I don't have a time to diff 2 versions. Might be
> regression.
> 
> 
> >>
> >>               /* stall; record URB status */
> >>               status = -EPIPE;
> >> +     } else if (rx_csr & (MUSB_RXCSR_DATAERROR | MUSB_RXCSR_H_ERROR)) {
> >>
> >> -     } else if (rx_csr & MUSB_RXCSR_H_ERROR) {
> >> -             dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
> >> -
> >> -             status = -EPROTO;
> >> -             musb_writeb(epio, MUSB_RXINTERVAL, 0);
> >> -
> >> -     } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> >> +             if (rx_csr & MUSB_RXCSR_H_ERROR) {
> >> +                     status = -EPROTO;
> >> +                     musb_writeb(epio, MUSB_RXINTERVAL, 0);
> >> +             }
> >
> > Please help me to understand how this change fixes the issue. I see the
> > most effect of the change here is directly 'goto finish' so that 'done'
> > flag is not set, then musb_advance_schedule() is not called. Is this the
> > case or I missed other important pieces?
> >
> 
> Right that is the goal. On this rxcsr_h_error kernel reschedules
> current interrupt.  And that continues forever. For example adding

The MUSB Programming Guide says CPU should clear this MUSB_RXCSR_H_ERROR
bit, but the current driver doesn't. I am wondering if this causes the
controller keeps generating the same interrupt. Can you please try the
following change instead to see if the lockup goes away?

@@ -1870,6 +1870,9 @@ void musb_host_rx(struct musb *musb, u8 epnum)
                status = -EPROTO;
                musb_writeb(epio, MUSB_RXINTERVAL, 0);
 
+               rx_csr &= ~MUSB_RXCSR_H_ERROR;
+               musb_writew(epio, MUSB_RXCSR, rx_csr);
+
        } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
 
                if (USB_ENDPOINT_XFER_ISOC != qh->type) {

Regards,
-Bin.

> msleep() can give some time for other processes. I'm not an expert in
> this chip but I think that right solution in that case is not try to
> reschedule and quick and allow hub to make reset and once again init
> all devices (in my case ppp/pppd also shutdowns and then I bring
> everything up with script.). The same behavior with dma and pio mode.
> 
> Regards,
> Max.
> 
> > Thanks,
> > -Bin.
> >
> >>
> >>               if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> >>                       dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
> >> --
> >> 1.9.1
> >>
> >> --
> >> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> >> the body of a message to majordomo@vger.kernel.org
> >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 
> 
> -- 
> Best regards,
> Maxim Uvarov

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Wed, Apr 27, 2016 at 02:13:56PM -0500, Bin Liu wrote:
> Hi,
> 
> On Wed, Apr 27, 2016 at 09:26:10PM +0300, Maxim Uvarov wrote:
> > 2016-04-27 18:46 GMT+03:00 Bin Liu <b-liu@ti.com>:
> > > Hi,
> > >
> > > On Wed, Apr 27, 2016 at 09:51:58AM +0300, Max Uvarov wrote:
> > >> Fix soft lockup when resetting remote device attached
> > >> to usb host. Configuration:
> > >> pppd -> musb hub -> usb-serial -> gsm modem
> > >
> > > I have heard a few reports similar to this symptom, but never been able
> > > to reproduce it on my side.
> > >
> > 
> > Ok, I can reproduce it almost very easy.
> > 
> > >> When gsm modem resets, musb rolls in incoming rx interrupts
> > >> which does not give any time to other application as result
> > >> it totally lock ups. Solution is to keep original logic for RXCSR_H_ERROR
> > >
> > > Have you looked where exact place in the interrupt routine the execution
> > > has stuck in?
> > >
> > 
> > It does not stuck. It goes to that line which print proto error over
> > and over again and
> > nothing stops that. After some time kernel reports lockup. But
> > actually it's not stuck,
> > all cpu time was eaten by executing that handlers.
> > 
> > 
> > >> and merge RXCSR_DATAERROR and RXCSR_H_ERROR branches to call same code
> > >> for setting rx stall with MUSB_RXCSR_H_WZC_BITS.
> > >
> > > MUSB_RXCSR_H_WZC_BITS itself does not set rx stall, it just ensures
> > > MUSB_RXCSR_H_RXSTALL not to be cleared. Please check its comment in
> > > musb_regs.h.
> > >
> > >>
> > >> Signed-off-by: Max Uvarov <muvarov@gmail.com>
> > >> ---
> > >>  v2: use bitwise or for error flags before logical and. (Sergei Shtylyov).
> > >>
> > >>  drivers/usb/musb/musb_host.c | 12 +++++-------
> > >>  1 file changed, 5 insertions(+), 7 deletions(-)
> > >>
> > >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> > >> index c3d5fc9..2d9aa78 100644
> > >> --- a/drivers/usb/musb/musb_host.c
> > >> +++ b/drivers/usb/musb/musb_host.c
> > >> @@ -1592,14 +1592,12 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> > >
> > > What kernel do you use? This line # is away off from upstream kernel.
> > >
> > 
> > I did this patch for 4.1 but 4.6 has the same problem and patch
> > cleanly applies to the latest torvalds/linux.git v4.6-rc5. This
> > interrupt handler has the same code.  And looks like on 3.14
> 
> Yeah, this code hasn't been chaned for year. But in general, it is
> prepfered to create patches on latest kernel to avoid other headache.
> 
> > everything worked. I don't have a time to diff 2 versions. Might be
> > regression.
> > 
> > 
> > >>
> > >>               /* stall; record URB status */
> > >>               status = -EPIPE;
> > >> +     } else if (rx_csr & (MUSB_RXCSR_DATAERROR | MUSB_RXCSR_H_ERROR)) {
> > >>
> > >> -     } else if (rx_csr & MUSB_RXCSR_H_ERROR) {
> > >> -             dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
> > >> -
> > >> -             status = -EPROTO;
> > >> -             musb_writeb(epio, MUSB_RXINTERVAL, 0);
> > >> -
> > >> -     } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> > >> +             if (rx_csr & MUSB_RXCSR_H_ERROR) {
> > >> +                     status = -EPROTO;
> > >> +                     musb_writeb(epio, MUSB_RXINTERVAL, 0);
> > >> +             }
> > >
> > > Please help me to understand how this change fixes the issue. I see the
> > > most effect of the change here is directly 'goto finish' so that 'done'
> > > flag is not set, then musb_advance_schedule() is not called. Is this the
> > > case or I missed other important pieces?
> > >
> > 
> > Right that is the goal. On this rxcsr_h_error kernel reschedules
> > current interrupt.  And that continues forever. For example adding
> 
> The MUSB Programming Guide says CPU should clear this MUSB_RXCSR_H_ERROR
> bit, but the current driver doesn't. I am wondering if this causes the
> controller keeps generating the same interrupt. Can you please try the
> following change instead to see if the lockup goes away?
> 
> @@ -1870,6 +1870,9 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>                 status = -EPROTO;
>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
>  
> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> +               musb_writew(epio, MUSB_RXCSR, rx_csr);

+               goto finish;

Please also add the line above. I will spend more time to understand
what is happening...

First of all, I don't like the idea of merging the two branches, it
makes the code ugly.

Regards,
-Bin.

> +
>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>  
>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> 
> Regards,
> -Bin.
> 
> > msleep() can give some time for other processes. I'm not an expert in
> > this chip but I think that right solution in that case is not try to
> > reschedule and quick and allow hub to make reset and once again init
> > all devices (in my case ppp/pppd also shutdowns and then I bring
> > everything up with script.). The same behavior with dma and pio mode.
> > 
> > Regards,
> > Max.
> > 
> > > Thanks,
> > > -Bin.
> > >
> > >>
> > >>               if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> > >>                       dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
> > >> --
> > >> 1.9.1
> > >>
> > >> --
> > >> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> > >> the body of a message to majordomo@vger.kernel.org
> > >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > 
> > 
> > 
> > -- 
> > Best regards,
> > Maxim Uvarov

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Maxim Uvarov]

2016-04-28 0:28 GMT+03:00 Bin Liu <b-liu@ti.com>:
> Hi,
>
> On Wed, Apr 27, 2016 at 02:13:56PM -0500, Bin Liu wrote:
>> Hi,
>>
>> On Wed, Apr 27, 2016 at 09:26:10PM +0300, Maxim Uvarov wrote:
>> > 2016-04-27 18:46 GMT+03:00 Bin Liu <b-liu@ti.com>:
>> > > Hi,
>> > >
>> > > On Wed, Apr 27, 2016 at 09:51:58AM +0300, Max Uvarov wrote:
>> > >> Fix soft lockup when resetting remote device attached
>> > >> to usb host. Configuration:
>> > >> pppd -> musb hub -> usb-serial -> gsm modem
>> > >
>> > > I have heard a few reports similar to this symptom, but never been able
>> > > to reproduce it on my side.
>> > >
>> >
>> > Ok, I can reproduce it almost very easy.
>> >
>> > >> When gsm modem resets, musb rolls in incoming rx interrupts
>> > >> which does not give any time to other application as result
>> > >> it totally lock ups. Solution is to keep original logic for RXCSR_H_ERROR
>> > >
>> > > Have you looked where exact place in the interrupt routine the execution
>> > > has stuck in?
>> > >
>> >
>> > It does not stuck. It goes to that line which print proto error over
>> > and over again and
>> > nothing stops that. After some time kernel reports lockup. But
>> > actually it's not stuck,
>> > all cpu time was eaten by executing that handlers.
>> >
>> >
>> > >> and merge RXCSR_DATAERROR and RXCSR_H_ERROR branches to call same code
>> > >> for setting rx stall with MUSB_RXCSR_H_WZC_BITS.
>> > >
>> > > MUSB_RXCSR_H_WZC_BITS itself does not set rx stall, it just ensures
>> > > MUSB_RXCSR_H_RXSTALL not to be cleared. Please check its comment in
>> > > musb_regs.h.
>> > >
>> > >>
>> > >> Signed-off-by: Max Uvarov <muvarov@gmail.com>
>> > >> ---
>> > >>  v2: use bitwise or for error flags before logical and. (Sergei Shtylyov).
>> > >>
>> > >>  drivers/usb/musb/musb_host.c | 12 +++++-------
>> > >>  1 file changed, 5 insertions(+), 7 deletions(-)
>> > >>
>> > >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>> > >> index c3d5fc9..2d9aa78 100644
>> > >> --- a/drivers/usb/musb/musb_host.c
>> > >> +++ b/drivers/usb/musb/musb_host.c
>> > >> @@ -1592,14 +1592,12 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>> > >
>> > > What kernel do you use? This line # is away off from upstream kernel.
>> > >
>> >
>> > I did this patch for 4.1 but 4.6 has the same problem and patch
>> > cleanly applies to the latest torvalds/linux.git v4.6-rc5. This
>> > interrupt handler has the same code.  And looks like on 3.14
>>
>> Yeah, this code hasn't been chaned for year. But in general, it is
>> prepfered to create patches on latest kernel to avoid other headache.
>>
>> > everything worked. I don't have a time to diff 2 versions. Might be
>> > regression.
>> >
>> >
>> > >>
>> > >>               /* stall; record URB status */
>> > >>               status = -EPIPE;
>> > >> +     } else if (rx_csr & (MUSB_RXCSR_DATAERROR | MUSB_RXCSR_H_ERROR)) {
>> > >>
>> > >> -     } else if (rx_csr & MUSB_RXCSR_H_ERROR) {
>> > >> -             dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
>> > >> -
>> > >> -             status = -EPROTO;
>> > >> -             musb_writeb(epio, MUSB_RXINTERVAL, 0);
>> > >> -
>> > >> -     } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>> > >> +             if (rx_csr & MUSB_RXCSR_H_ERROR) {
>> > >> +                     status = -EPROTO;
>> > >> +                     musb_writeb(epio, MUSB_RXINTERVAL, 0);
>> > >> +             }
>> > >
>> > > Please help me to understand how this change fixes the issue. I see the
>> > > most effect of the change here is directly 'goto finish' so that 'done'
>> > > flag is not set, then musb_advance_schedule() is not called. Is this the
>> > > case or I missed other important pieces?
>> > >
>> >
>> > Right that is the goal. On this rxcsr_h_error kernel reschedules
>> > current interrupt.  And that continues forever. For example adding
>>
>> The MUSB Programming Guide says CPU should clear this MUSB_RXCSR_H_ERROR
>> bit, but the current driver doesn't. I am wondering if this causes the
>> controller keeps generating the same interrupt. Can you please try the
>> following change instead to see if the lockup goes away?
>>
>> @@ -1870,6 +1870,9 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>>                 status = -EPROTO;
>>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
>>
>> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>
> +               goto finish;
>
> Please also add the line above. I will spend more time to understand
> what is happening...
>

Hello Bin,

yes, it also works with that reset and go to finish:

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index c3d5fc9..8cd98e7 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
                status = -EPROTO;
                musb_writeb(epio, MUSB_RXINTERVAL, 0);

+               rx_csr &= ~MUSB_RXCSR_H_ERROR;
+               musb_writew(epio, MUSB_RXCSR, rx_csr);
+
+               goto finish;
        } else if (rx_csr & MUSB_RXCSR_DATAERROR) {

                if (USB_ENDPOINT_XFER_ISOC != qh->type) {


That I think a key thing, which is done in other error. If that change
is good for you than I'm also happy with it.

I also not sure if musb_writeb(epio, MUSB_RXINTERVAL, 0); is needed.
In my case it's the same result with it and without it.
In other scenarios might be reasonable...


> First of all, I don't like the idea of merging the two branches, it
> makes the code ugly.

Yes, I don't like that function at all, it's too long and difficult to
read if you first look on it first time. It will be good to split it
on 3 small functions for each big if.

Maxim.

>
> Regards,
> -Bin.
>
>> +
>>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>>
>>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>>
>> Regards,
>> -Bin.
>>
>> > msleep() can give some time for other processes. I'm not an expert in
>> > this chip but I think that right solution in that case is not try to
>> > reschedule and quick and allow hub to make reset and once again init
>> > all devices (in my case ppp/pppd also shutdowns and then I bring
>> > everything up with script.). The same behavior with dma and pio mode.
>> >
>> > Regards,
>> > Max.
>> >
>> > > Thanks,
>> > > -Bin.
>> > >
>> > >>
>> > >>               if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>> > >>                       dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
>> > >> --
>> > >> 1.9.1
>> > >>
>> > >> --
>> > >> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>> > >> the body of a message to majordomo@vger.kernel.org
>> > >> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> >
>> >
>> >
>> > --
>> > Best regards,
>> > Maxim Uvarov



-- 
Best regards,
Maxim Uvarov

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:

[snip]

> Hello Bin,
> 
> yes, it also works with that reset and go to finish:
> 
> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> index c3d5fc9..8cd98e7 100644
> --- a/drivers/usb/musb/musb_host.c
> +++ b/drivers/usb/musb/musb_host.c
> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>                 status = -EPROTO;
>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
> 
> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
> +
> +               goto finish;
>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> 
>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> 

Thanks for testing it.

> 
> That I think a key thing, which is done in other error. If that change
> is good for you than I'm also happy with it.

We need to understand why the controller keeps generating the same
interrupt to come out a proper fix.

I will take a look. But I can only use my spare time on this, so be
patient.

> 
> I also not sure if musb_writeb(epio, MUSB_RXINTERVAL, 0); is needed.
> In my case it's the same result with it and without it.
> In other scenarios might be reasonable...

It disables NAK timeout.

> 
> 
> > First of all, I don't like the idea of merging the two branches, it
> > makes the code ugly.
> 
> Yes, I don't like that function at all, it's too long and difficult to
> read if you first look on it first time. It will be good to split it
> on 3 small functions for each big if.

This particular function is not that hard to understand, but the driver
in general is messy. But I am not sure if anyone in the community can
refactory this driver. The community had some effort in the past to
clean up this driver, but it always broke usecases on different
platforms.

Regards,
-Bin.

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Yegor Yefremov]

On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
> Hi,
>
> On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
>
> [snip]
>
>> Hello Bin,
>>
>> yes, it also works with that reset and go to finish:
>>
>> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>> index c3d5fc9..8cd98e7 100644
>> --- a/drivers/usb/musb/musb_host.c
>> +++ b/drivers/usb/musb/musb_host.c
>> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>>                 status = -EPROTO;
>>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
>>
>> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>> +
>> +               goto finish;
>>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>>
>>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>>
>
> Thanks for testing it.

Have tested your patch and now both FT4232 and Huawei don't freeze on removal.

Bin, Max thanks for fixing this issue.

Tested-by: Yegor Yefremov <yegorslists@googlemail.com>

>> That I think a key thing, which is done in other error. If that change
>> is good for you than I'm also happy with it.
>
> We need to understand why the controller keeps generating the same
> interrupt to come out a proper fix.
>
> I will take a look. But I can only use my spare time on this, so be
> patient.
>
>>
>> I also not sure if musb_writeb(epio, MUSB_RXINTERVAL, 0); is needed.
>> In my case it's the same result with it and without it.
>> In other scenarios might be reasonable...
>
> It disables NAK timeout.
>
>>
>>
>> > First of all, I don't like the idea of merging the two branches, it
>> > makes the code ugly.
>>
>> Yes, I don't like that function at all, it's too long and difficult to
>> read if you first look on it first time. It will be good to split it
>> on 3 small functions for each big if.
>
> This particular function is not that hard to understand, but the driver
> in general is messy. But I am not sure if anyone in the community can
> refactory this driver. The community had some effort in the past to
> clean up this driver, but it always broke usecases on different
> platforms.
>
> Regards,
> -Bin.

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Tue, May 03, 2016 at 12:03:52PM +0200, Yegor Yefremov wrote:
> On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
> > Hi,
> >
> > On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
> >
> > [snip]
> >
> >> Hello Bin,
> >>
> >> yes, it also works with that reset and go to finish:
> >>
> >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> >> index c3d5fc9..8cd98e7 100644
> >> --- a/drivers/usb/musb/musb_host.c
> >> +++ b/drivers/usb/musb/musb_host.c
> >> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> >>                 status = -EPROTO;
> >>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
> >>
> >> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> >> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
> >> +
> >> +               goto finish;
> >>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> >>
> >>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> >>
> >
> > Thanks for testing it.
> 
> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
> 
> Bin, Max thanks for fixing this issue.
> 
> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>

Thanks for testing.

Can you please test the patch [1] instead? I'd like to use it as the
fix.

Regards,
-Bin.

[1] http://marc.info/?l=linux-usb&m=146222355213935&w=2

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Yegor Yefremov]

On Tue, May 3, 2016 at 3:48 PM, Bin Liu <b-liu@ti.com> wrote:
> Hi,
>
> On Tue, May 03, 2016 at 12:03:52PM +0200, Yegor Yefremov wrote:
>> On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
>> > Hi,
>> >
>> > On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
>> >
>> > [snip]
>> >
>> >> Hello Bin,
>> >>
>> >> yes, it also works with that reset and go to finish:
>> >>
>> >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>> >> index c3d5fc9..8cd98e7 100644
>> >> --- a/drivers/usb/musb/musb_host.c
>> >> +++ b/drivers/usb/musb/musb_host.c
>> >> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>> >>                 status = -EPROTO;
>> >>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
>> >>
>> >> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>> >> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>> >> +
>> >> +               goto finish;
>> >>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>> >>
>> >>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>> >>
>> >
>> > Thanks for testing it.
>>
>> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
>>
>> Bin, Max thanks for fixing this issue.
>>
>> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
>
> Thanks for testing.
>
> Can you please test the patch [1] instead? I'd like to use it as the
> fix.
>
> [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2

The patch behaves the same as the previous one.

Kernel: 4.6-rc6

Yegor

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Tue, May 03, 2016 at 04:25:58PM +0200, Yegor Yefremov wrote:
> On Tue, May 3, 2016 at 3:48 PM, Bin Liu <b-liu@ti.com> wrote:
> > Hi,
> >
> > On Tue, May 03, 2016 at 12:03:52PM +0200, Yegor Yefremov wrote:
> >> On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
> >> > Hi,
> >> >
> >> > On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
> >> >
> >> > [snip]
> >> >
> >> >> Hello Bin,
> >> >>
> >> >> yes, it also works with that reset and go to finish:
> >> >>
> >> >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> >> >> index c3d5fc9..8cd98e7 100644
> >> >> --- a/drivers/usb/musb/musb_host.c
> >> >> +++ b/drivers/usb/musb/musb_host.c
> >> >> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> >> >>                 status = -EPROTO;
> >> >>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
> >> >>
> >> >> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> >> >> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
> >> >> +
> >> >> +               goto finish;
> >> >>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> >> >>
> >> >>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> >> >>
> >> >
> >> > Thanks for testing it.
> >>
> >> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
> >>
> >> Bin, Max thanks for fixing this issue.
> >>
> >> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
> >
> > Thanks for testing.
> >
> > Can you please test the patch [1] instead? I'd like to use it as the
> > fix.
> >
> > [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
> 
> The patch behaves the same as the previous one.
> 
> Kernel: 4.6-rc6

Thanks for testing. I will add your Tested-by.

Regards,
-Bin.

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Yegor Yefremov]

On Tue, May 3, 2016 at 4:35 PM, Bin Liu <b-liu@ti.com> wrote:
> Hi,
>
> On Tue, May 03, 2016 at 04:25:58PM +0200, Yegor Yefremov wrote:
>> On Tue, May 3, 2016 at 3:48 PM, Bin Liu <b-liu@ti.com> wrote:
>> > Hi,
>> >
>> > On Tue, May 03, 2016 at 12:03:52PM +0200, Yegor Yefremov wrote:
>> >> On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
>> >> > Hi,
>> >> >
>> >> > On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
>> >> >
>> >> > [snip]
>> >> >
>> >> >> Hello Bin,
>> >> >>
>> >> >> yes, it also works with that reset and go to finish:
>> >> >>
>> >> >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>> >> >> index c3d5fc9..8cd98e7 100644
>> >> >> --- a/drivers/usb/musb/musb_host.c
>> >> >> +++ b/drivers/usb/musb/musb_host.c
>> >> >> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>> >> >>                 status = -EPROTO;
>> >> >>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
>> >> >>
>> >> >> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>> >> >> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>> >> >> +
>> >> >> +               goto finish;
>> >> >>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>> >> >>
>> >> >>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>> >> >>
>> >> >
>> >> > Thanks for testing it.
>> >>
>> >> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
>> >>
>> >> Bin, Max thanks for fixing this issue.
>> >>
>> >> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
>> >
>> > Thanks for testing.
>> >
>> > Can you please test the patch [1] instead? I'd like to use it as the
>> > fix.
>> >
>> > [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
>>
>> The patch behaves the same as the previous one.
>>
>> Kernel: 4.6-rc6
>
> Thanks for testing. I will add your Tested-by.

If you'll resend this patch, it would be good to add it to stable
kernels. I've tested 3.18.32 and it fixes the error too.

Yegor

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Wed, May 04, 2016 at 04:49:50PM +0200, Yegor Yefremov wrote:
> On Tue, May 3, 2016 at 4:35 PM, Bin Liu <b-liu@ti.com> wrote:
> > Hi,
> >
> > On Tue, May 03, 2016 at 04:25:58PM +0200, Yegor Yefremov wrote:
> >> On Tue, May 3, 2016 at 3:48 PM, Bin Liu <b-liu@ti.com> wrote:
> >> > Hi,
> >> >
> >> > On Tue, May 03, 2016 at 12:03:52PM +0200, Yegor Yefremov wrote:
> >> >> On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
> >> >> > Hi,
> >> >> >
> >> >> > On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
> >> >> >
> >> >> > [snip]
> >> >> >
> >> >> >> Hello Bin,
> >> >> >>
> >> >> >> yes, it also works with that reset and go to finish:
> >> >> >>
> >> >> >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> >> >> >> index c3d5fc9..8cd98e7 100644
> >> >> >> --- a/drivers/usb/musb/musb_host.c
> >> >> >> +++ b/drivers/usb/musb/musb_host.c
> >> >> >> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> >> >> >>                 status = -EPROTO;
> >> >> >>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
> >> >> >>
> >> >> >> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> >> >> >> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
> >> >> >> +
> >> >> >> +               goto finish;
> >> >> >>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> >> >> >>
> >> >> >>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> >> >> >>
> >> >> >
> >> >> > Thanks for testing it.
> >> >>
> >> >> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
> >> >>
> >> >> Bin, Max thanks for fixing this issue.
> >> >>
> >> >> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
> >> >
> >> > Thanks for testing.
> >> >
> >> > Can you please test the patch [1] instead? I'd like to use it as the
> >> > fix.
> >> >
> >> > [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
> >>
> >> The patch behaves the same as the previous one.
> >>
> >> Kernel: 4.6-rc6
> >
> > Thanks for testing. I will add your Tested-by.
> 
> If you'll resend this patch, it would be good to add it to stable
> kernels. I've tested 3.18.32 and it fixes the error too.
> 

Thanks for testing.

My plan is to not rush it into stable, but let it sit in v4.7 for a
while first.

Regards,
-Bin.

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Sergei Shtylyov]

Hello.

On 05/04/2016 09:56 PM, Bin Liu wrote:

>>>>>>>> yes, it also works with that reset and go to finish:
>>>>>>>>
>>>>>>>> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>>>>>>>> index c3d5fc9..8cd98e7 100644
>>>>>>>> --- a/drivers/usb/musb/musb_host.c
>>>>>>>> +++ b/drivers/usb/musb/musb_host.c
>>>>>>>> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>>>>>>>>                  status = -EPROTO;
>>>>>>>>                  musb_writeb(epio, MUSB_RXINTERVAL, 0);
>>>>>>>>
>>>>>>>> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>>>>>>>> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>>>>>>>> +
>>>>>>>> +               goto finish;
>>>>>>>>          } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>>>>>>>>
>>>>>>>>                  if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>>>>>>>>
>>>>>>>
>>>>>>> Thanks for testing it.
>>>>>>
>>>>>> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
>>>>>>
>>>>>> Bin, Max thanks for fixing this issue.
>>>>>>
>>>>>> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
>>>>>
>>>>> Thanks for testing.
>>>>>
>>>>> Can you please test the patch [1] instead? I'd like to use it as the
>>>>> fix.
>>>>>
>>>>> [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
>>>>
>>>> The patch behaves the same as the previous one.
>>>>
>>>> Kernel: 4.6-rc6
>>>
>>> Thanks for testing. I will add your Tested-by.
>>
>> If you'll resend this patch, it would be good to add it to stable
>> kernels. I've tested 3.18.32 and it fixes the error too.

> Thanks for testing.
>
> My plan is to not rush it into stable, but let it sit in v4.7 for a
> while first.

    Are you serious? Fixing interrupt storm due to not cleared interrupt bit 
will only be done in 4.7?

> Regards,
> -Bin.

MBR, Sergei

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Wed, May 04, 2016 at 10:02:16PM +0300, Sergei Shtylyov wrote:
> Hello.
> 
> On 05/04/2016 09:56 PM, Bin Liu wrote:
> 
> >>>>>>>>yes, it also works with that reset and go to finish:
> >>>>>>>>
> >>>>>>>>diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> >>>>>>>>index c3d5fc9..8cd98e7 100644
> >>>>>>>>--- a/drivers/usb/musb/musb_host.c
> >>>>>>>>+++ b/drivers/usb/musb/musb_host.c
> >>>>>>>>@@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> >>>>>>>>                 status = -EPROTO;
> >>>>>>>>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
> >>>>>>>>
> >>>>>>>>+               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> >>>>>>>>+               musb_writew(epio, MUSB_RXCSR, rx_csr);
> >>>>>>>>+
> >>>>>>>>+               goto finish;
> >>>>>>>>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> >>>>>>>>
> >>>>>>>>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> >>>>>>>>
> >>>>>>>
> >>>>>>>Thanks for testing it.
> >>>>>>
> >>>>>>Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
> >>>>>>
> >>>>>>Bin, Max thanks for fixing this issue.
> >>>>>>
> >>>>>>Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
> >>>>>
> >>>>>Thanks for testing.
> >>>>>
> >>>>>Can you please test the patch [1] instead? I'd like to use it as the
> >>>>>fix.
> >>>>>
> >>>>>[1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
> >>>>
> >>>>The patch behaves the same as the previous one.
> >>>>
> >>>>Kernel: 4.6-rc6
> >>>
> >>>Thanks for testing. I will add your Tested-by.
> >>
> >>If you'll resend this patch, it would be good to add it to stable
> >>kernels. I've tested 3.18.32 and it fixes the error too.
> 
> >Thanks for testing.
> >
> >My plan is to not rush it into stable, but let it sit in v4.7 for a
> >while first.
> 
>    Are you serious? Fixing interrupt storm due to not cleared
> interrupt bit will only be done in 4.7?

Well, I am new to maintianer's role, and thought there is only one week
away to v4.7 merge window, there is no big difference to let this patch
get into v4.7-rc1. If getting the fix into upstream as soon as possible
is important, I will send it for 4.6-rc7.

BTY, the issue is not because of not clearing interrupt bit, but the hub
has no chance to report the disconnect event, which causes the
controller keeps generating the interrupt for every new rx urb.

Regards,
-Bin.

> 
> >Regards,
> >-Bin.
> 
> MBR, Sergei
> 

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Greg KH]

On Wed, May 04, 2016 at 02:17:15PM -0500, Bin Liu wrote:
> Hi,
> 
> On Wed, May 04, 2016 at 10:02:16PM +0300, Sergei Shtylyov wrote:
> > Hello.
> > 
> > On 05/04/2016 09:56 PM, Bin Liu wrote:
> > 
> > >>>>>>>>yes, it also works with that reset and go to finish:
> > >>>>>>>>
> > >>>>>>>>diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> > >>>>>>>>index c3d5fc9..8cd98e7 100644
> > >>>>>>>>--- a/drivers/usb/musb/musb_host.c
> > >>>>>>>>+++ b/drivers/usb/musb/musb_host.c
> > >>>>>>>>@@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> > >>>>>>>>                 status = -EPROTO;
> > >>>>>>>>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
> > >>>>>>>>
> > >>>>>>>>+               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> > >>>>>>>>+               musb_writew(epio, MUSB_RXCSR, rx_csr);
> > >>>>>>>>+
> > >>>>>>>>+               goto finish;
> > >>>>>>>>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> > >>>>>>>>
> > >>>>>>>>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> > >>>>>>>>
> > >>>>>>>
> > >>>>>>>Thanks for testing it.
> > >>>>>>
> > >>>>>>Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
> > >>>>>>
> > >>>>>>Bin, Max thanks for fixing this issue.
> > >>>>>>
> > >>>>>>Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
> > >>>>>
> > >>>>>Thanks for testing.
> > >>>>>
> > >>>>>Can you please test the patch [1] instead? I'd like to use it as the
> > >>>>>fix.
> > >>>>>
> > >>>>>[1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
> > >>>>
> > >>>>The patch behaves the same as the previous one.
> > >>>>
> > >>>>Kernel: 4.6-rc6
> > >>>
> > >>>Thanks for testing. I will add your Tested-by.
> > >>
> > >>If you'll resend this patch, it would be good to add it to stable
> > >>kernels. I've tested 3.18.32 and it fixes the error too.
> > 
> > >Thanks for testing.
> > >
> > >My plan is to not rush it into stable, but let it sit in v4.7 for a
> > >while first.
> > 
> >    Are you serious? Fixing interrupt storm due to not cleared
> > interrupt bit will only be done in 4.7?
> 
> Well, I am new to maintianer's role, and thought there is only one week
> away to v4.7 merge window, there is no big difference to let this patch
> get into v4.7-rc1. If getting the fix into upstream as soon as possible
> is important, I will send it for 4.6-rc7.

No, your original idea of getting it into 4.7-rc1 first is the best, I
will not take this for 4.6-final right now, it's not a regression.

thanks,

greg k-h

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Wed, May 04, 2016 at 01:19:27PM -0700, Greg KH wrote:
> On Wed, May 04, 2016 at 02:17:15PM -0500, Bin Liu wrote:
> > Hi,
> > 
> > On Wed, May 04, 2016 at 10:02:16PM +0300, Sergei Shtylyov wrote:
> > > Hello.
> > > 
> > > On 05/04/2016 09:56 PM, Bin Liu wrote:
> > > 
> > > >>>>>>>>yes, it also works with that reset and go to finish:
> > > >>>>>>>>
> > > >>>>>>>>diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> > > >>>>>>>>index c3d5fc9..8cd98e7 100644
> > > >>>>>>>>--- a/drivers/usb/musb/musb_host.c
> > > >>>>>>>>+++ b/drivers/usb/musb/musb_host.c
> > > >>>>>>>>@@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> > > >>>>>>>>                 status = -EPROTO;
> > > >>>>>>>>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
> > > >>>>>>>>
> > > >>>>>>>>+               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> > > >>>>>>>>+               musb_writew(epio, MUSB_RXCSR, rx_csr);
> > > >>>>>>>>+
> > > >>>>>>>>+               goto finish;
> > > >>>>>>>>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> > > >>>>>>>>
> > > >>>>>>>>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> > > >>>>>>>>
> > > >>>>>>>
> > > >>>>>>>Thanks for testing it.
> > > >>>>>>
> > > >>>>>>Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
> > > >>>>>>
> > > >>>>>>Bin, Max thanks for fixing this issue.
> > > >>>>>>
> > > >>>>>>Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
> > > >>>>>
> > > >>>>>Thanks for testing.
> > > >>>>>
> > > >>>>>Can you please test the patch [1] instead? I'd like to use it as the
> > > >>>>>fix.
> > > >>>>>
> > > >>>>>[1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
> > > >>>>
> > > >>>>The patch behaves the same as the previous one.
> > > >>>>
> > > >>>>Kernel: 4.6-rc6
> > > >>>
> > > >>>Thanks for testing. I will add your Tested-by.
> > > >>
> > > >>If you'll resend this patch, it would be good to add it to stable
> > > >>kernels. I've tested 3.18.32 and it fixes the error too.
> > > 
> > > >Thanks for testing.
> > > >
> > > >My plan is to not rush it into stable, but let it sit in v4.7 for a
> > > >while first.
> > > 
> > >    Are you serious? Fixing interrupt storm due to not cleared
> > > interrupt bit will only be done in 4.7?
> > 
> > Well, I am new to maintianer's role, and thought there is only one week
> > away to v4.7 merge window, there is no big difference to let this patch
> > get into v4.7-rc1. If getting the fix into upstream as soon as possible
> > is important, I will send it for 4.6-rc7.
> 
> No, your original idea of getting it into 4.7-rc1 first is the best, I
> will not take this for 4.6-final right now, it's not a regression.

Ok, noted.

> 
> thanks,
> 
> greg k-h

Regards,
-Bin.

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Sergei Shtylyov]

Hello.

On 5/4/2016 10:17 PM, Bin Liu wrote:

>>>>>>>>>> yes, it also works with that reset and go to finish:
>>>>>>>>>>
>>>>>>>>>> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>>>>>>>>>> index c3d5fc9..8cd98e7 100644
>>>>>>>>>> --- a/drivers/usb/musb/musb_host.c
>>>>>>>>>> +++ b/drivers/usb/musb/musb_host.c
>>>>>>>>>> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>>>>>>>>>>                 status = -EPROTO;
>>>>>>>>>>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
>>>>>>>>>>
>>>>>>>>>> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>>>>>>>>>> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>>>>>>>>>> +
>>>>>>>>>> +               goto finish;
>>>>>>>>>>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>>>>>>>>>>
>>>>>>>>>>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Thanks for testing it.
>>>>>>>>
>>>>>>>> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
>>>>>>>>
>>>>>>>> Bin, Max thanks for fixing this issue.
>>>>>>>>
>>>>>>>> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
>>>>>>>
>>>>>>> Thanks for testing.
>>>>>>>
>>>>>>> Can you please test the patch [1] instead? I'd like to use it as the
>>>>>>> fix.
>>>>>>>
>>>>>>> [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
>>>>>>
>>>>>> The patch behaves the same as the previous one.
>>>>>>
>>>>>> Kernel: 4.6-rc6
>>>>>
>>>>> Thanks for testing. I will add your Tested-by.
>>>>
>>>> If you'll resend this patch, it would be good to add it to stable
>>>> kernels. I've tested 3.18.32 and it fixes the error too.
>>
>>> Thanks for testing.
>>>
>>> My plan is to not rush it into stable, but let it sit in v4.7 for a
>>> while first.
>>
>>    Are you serious? Fixing interrupt storm due to not cleared
>> interrupt bit will only be done in 4.7?
>
> Well, I am new to maintianer's role, and thought there is only one week
> away to v4.7 merge window, there is no big difference to let this patch
> get into v4.7-rc1. If getting the fix into upstream as soon as possible
> is important, I will send it for 4.6-rc7.
>
> BTY, the issue is not because of not clearing interrupt bit, but the hub
> has no chance to report the disconnect event, which causes the
> controller keeps generating the interrupt for every new rx urb.

    Sorry, looking at the Mentor manuals, I got the impression that whenever 
the RXCSR.Error is set, there's interrupt. Probably they meant that the 
interrupt is generated only on transition from 0 to 1....

> Regards,
> -Bin.

MBR, Sergei

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi,

On Thu, May 05, 2016 at 04:21:23PM +0300, Sergei Shtylyov wrote:
> Hello.
> 
> On 5/4/2016 10:17 PM, Bin Liu wrote:
> 
> >>>>>>>>>>yes, it also works with that reset and go to finish:
> >>>>>>>>>>
> >>>>>>>>>>diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> >>>>>>>>>>index c3d5fc9..8cd98e7 100644
> >>>>>>>>>>--- a/drivers/usb/musb/musb_host.c
> >>>>>>>>>>+++ b/drivers/usb/musb/musb_host.c
> >>>>>>>>>>@@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> >>>>>>>>>>                status = -EPROTO;
> >>>>>>>>>>                musb_writeb(epio, MUSB_RXINTERVAL, 0);
> >>>>>>>>>>
> >>>>>>>>>>+               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> >>>>>>>>>>+               musb_writew(epio, MUSB_RXCSR, rx_csr);
> >>>>>>>>>>+
> >>>>>>>>>>+               goto finish;
> >>>>>>>>>>        } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> >>>>>>>>>>
> >>>>>>>>>>                if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> >>>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>Thanks for testing it.
> >>>>>>>>
> >>>>>>>>Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
> >>>>>>>>
> >>>>>>>>Bin, Max thanks for fixing this issue.
> >>>>>>>>
> >>>>>>>>Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
> >>>>>>>
> >>>>>>>Thanks for testing.
> >>>>>>>
> >>>>>>>Can you please test the patch [1] instead? I'd like to use it as the
> >>>>>>>fix.
> >>>>>>>
> >>>>>>>[1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
> >>>>>>
> >>>>>>The patch behaves the same as the previous one.
> >>>>>>
> >>>>>>Kernel: 4.6-rc6
> >>>>>
> >>>>>Thanks for testing. I will add your Tested-by.
> >>>>
> >>>>If you'll resend this patch, it would be good to add it to stable
> >>>>kernels. I've tested 3.18.32 and it fixes the error too.
> >>
> >>>Thanks for testing.
> >>>
> >>>My plan is to not rush it into stable, but let it sit in v4.7 for a
> >>>while first.
> >>
> >>   Are you serious? Fixing interrupt storm due to not cleared
> >>interrupt bit will only be done in 4.7?
> >
> >Well, I am new to maintianer's role, and thought there is only one week
> >away to v4.7 merge window, there is no big difference to let this patch
> >get into v4.7-rc1. If getting the fix into upstream as soon as possible
> >is important, I will send it for 4.6-rc7.
> >
> >BTY, the issue is not because of not clearing interrupt bit, but the hub
> >has no chance to report the disconnect event, which causes the
> >controller keeps generating the interrupt for every new rx urb.
> 
>    Sorry, looking at the Mentor manuals, I got the impression that
> whenever the RXCSR.Error is set, there's interrupt. Probably they

This is my understanding of the manual too.

> meant that the interrupt is generated only on transition from 0 to
> 1....

What transition? the RXCSR bit? 'set' means from 0 to 1, 'clear' means 1
-> 0, right? I don't see you have any misunderstanding.

> 
> >Regards,
> >-Bin.
> 
> MBR, Sergei
> 

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Sergei Shtylyov]

On 5/5/2016 4:31 PM, Bin Liu wrote:

>>>>>>>>>>>> yes, it also works with that reset and go to finish:
>>>>>>>>>>>>
>>>>>>>>>>>> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>>>>>>>>>>>> index c3d5fc9..8cd98e7 100644
>>>>>>>>>>>> --- a/drivers/usb/musb/musb_host.c
>>>>>>>>>>>> +++ b/drivers/usb/musb/musb_host.c
>>>>>>>>>>>> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>>>>>>>>>>>>                status = -EPROTO;
>>>>>>>>>>>>                musb_writeb(epio, MUSB_RXINTERVAL, 0);
>>>>>>>>>>>>
>>>>>>>>>>>> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>>>>>>>>>>>> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>>>>>>>>>>>> +
>>>>>>>>>>>> +               goto finish;
>>>>>>>>>>>>        } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>>>>>>>>>>>>
>>>>>>>>>>>>                if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Thanks for testing it.
>>>>>>>>>>
>>>>>>>>>> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
>>>>>>>>>>
>>>>>>>>>> Bin, Max thanks for fixing this issue.
>>>>>>>>>>
>>>>>>>>>> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
>>>>>>>>>
>>>>>>>>> Thanks for testing.
>>>>>>>>>
>>>>>>>>> Can you please test the patch [1] instead? I'd like to use it as the
>>>>>>>>> fix.
>>>>>>>>>
>>>>>>>>> [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
>>>>>>>>
>>>>>>>> The patch behaves the same as the previous one.
>>>>>>>>
>>>>>>>> Kernel: 4.6-rc6
>>>>>>>
>>>>>>> Thanks for testing. I will add your Tested-by.
>>>>>>
>>>>>> If you'll resend this patch, it would be good to add it to stable
>>>>>> kernels. I've tested 3.18.32 and it fixes the error too.
>>>>
>>>>> Thanks for testing.
>>>>>
>>>>> My plan is to not rush it into stable, but let it sit in v4.7 for a
>>>>> while first.
>>>>
>>>>   Are you serious? Fixing interrupt storm due to not cleared
>>>> interrupt bit will only be done in 4.7?
>>>
>>> Well, I am new to maintianer's role, and thought there is only one week
>>> away to v4.7 merge window, there is no big difference to let this patch
>>> get into v4.7-rc1. If getting the fix into upstream as soon as possible
>>> is important, I will send it for 4.6-rc7.
>>>
>>> BTY, the issue is not because of not clearing interrupt bit, but the hub
>>> has no chance to report the disconnect event, which causes the
>>> controller keeps generating the interrupt for every new rx urb.
>>
>>    Sorry, looking at the Mentor manuals, I got the impression that
>> whenever the RXCSR.Error is set, there's interrupt. Probably they
>
> This is my understanding of the manual too.
>
>> meant that the interrupt is generated only on transition from 0 to
>> 1....
>
> What transition? the RXCSR bit?

    Of course.

> 'set' means from 0 to 1, 'clear' means 1 -> 0, right?

    Well, in my understanding "set" means 1 and "clear" means 0.

> I don't see you have any misunderstanding.

>>> Regards,
>>> -Bin.

MBR, Sergei

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

On Thu, May 05, 2016 at 04:39:06PM +0300, Sergei Shtylyov wrote:
> On 5/5/2016 4:31 PM, Bin Liu wrote:
> 
> >>>>>>>>>>>>yes, it also works with that reset and go to finish:
> >>>>>>>>>>>>
> >>>>>>>>>>>>diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> >>>>>>>>>>>>index c3d5fc9..8cd98e7 100644
> >>>>>>>>>>>>--- a/drivers/usb/musb/musb_host.c
> >>>>>>>>>>>>+++ b/drivers/usb/musb/musb_host.c
> >>>>>>>>>>>>@@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> >>>>>>>>>>>>               status = -EPROTO;
> >>>>>>>>>>>>               musb_writeb(epio, MUSB_RXINTERVAL, 0);
> >>>>>>>>>>>>
> >>>>>>>>>>>>+               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> >>>>>>>>>>>>+               musb_writew(epio, MUSB_RXCSR, rx_csr);
> >>>>>>>>>>>>+
> >>>>>>>>>>>>+               goto finish;
> >>>>>>>>>>>>       } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> >>>>>>>>>>>>
> >>>>>>>>>>>>               if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> >>>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>Thanks for testing it.
> >>>>>>>>>>
> >>>>>>>>>>Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
> >>>>>>>>>>
> >>>>>>>>>>Bin, Max thanks for fixing this issue.
> >>>>>>>>>>
> >>>>>>>>>>Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
> >>>>>>>>>
> >>>>>>>>>Thanks for testing.
> >>>>>>>>>
> >>>>>>>>>Can you please test the patch [1] instead? I'd like to use it as the
> >>>>>>>>>fix.
> >>>>>>>>>
> >>>>>>>>>[1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
> >>>>>>>>
> >>>>>>>>The patch behaves the same as the previous one.
> >>>>>>>>
> >>>>>>>>Kernel: 4.6-rc6
> >>>>>>>
> >>>>>>>Thanks for testing. I will add your Tested-by.
> >>>>>>
> >>>>>>If you'll resend this patch, it would be good to add it to stable
> >>>>>>kernels. I've tested 3.18.32 and it fixes the error too.
> >>>>
> >>>>>Thanks for testing.
> >>>>>
> >>>>>My plan is to not rush it into stable, but let it sit in v4.7 for a
> >>>>>while first.
> >>>>
> >>>>  Are you serious? Fixing interrupt storm due to not cleared
> >>>>interrupt bit will only be done in 4.7?
> >>>
> >>>Well, I am new to maintianer's role, and thought there is only one week
> >>>away to v4.7 merge window, there is no big difference to let this patch
> >>>get into v4.7-rc1. If getting the fix into upstream as soon as possible
> >>>is important, I will send it for 4.6-rc7.
> >>>
> >>>BTY, the issue is not because of not clearing interrupt bit, but the hub
> >>>has no chance to report the disconnect event, which causes the
> >>>controller keeps generating the interrupt for every new rx urb.
> >>
> >>   Sorry, looking at the Mentor manuals, I got the impression that
> >>whenever the RXCSR.Error is set, there's interrupt. Probably they
> >
> >This is my understanding of the manual too.
> >
> >>meant that the interrupt is generated only on transition from 0 to
> >>1....
> >
> >What transition? the RXCSR bit?
> 
>    Of course.
> 
> >'set' means from 0 to 1, 'clear' means 1 -> 0, right?
> 
>    Well, in my understanding "set" means 1 and "clear" means 0.

This is right. I didn't mean raising or falling edge when mentioning
0->1 or 1->0. We don't know when exactly the controller generates the
interrupt when CSR bit changes, and we/driver don't care.

> 
> >I don't see you have any misunderstanding.
> 
> >>>Regards,
> >>>-Bin.
> 
> MBR, Sergei
> 

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Hi Yegor and Max,

On Tue, May 03, 2016 at 04:25:58PM +0200, Yegor Yefremov wrote:
> On Tue, May 3, 2016 at 3:48 PM, Bin Liu <b-liu@ti.com> wrote:
> > Hi,
> >
> > On Tue, May 03, 2016 at 12:03:52PM +0200, Yegor Yefremov wrote:
> >> On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
> >> > Hi,
> >> >
> >> > On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
> >> >
> >> > [snip]
> >> >
> >> >> Hello Bin,
> >> >>
> >> >> yes, it also works with that reset and go to finish:
> >> >>
> >> >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> >> >> index c3d5fc9..8cd98e7 100644
> >> >> --- a/drivers/usb/musb/musb_host.c
> >> >> +++ b/drivers/usb/musb/musb_host.c
> >> >> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
> >> >>                 status = -EPROTO;
> >> >>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
> >> >>
> >> >> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
> >> >> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
> >> >> +
> >> >> +               goto finish;
> >> >>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
> >> >>
> >> >>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
> >> >>
> >> >
> >> > Thanks for testing it.
> >>
> >> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
> >>
> >> Bin, Max thanks for fixing this issue.
> >>
> >> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
> >
> > Thanks for testing.
> >
> > Can you please test the patch [1] instead? I'd like to use it as the
> > fix.
> >
> > [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
> 
> The patch behaves the same as the previous one.

Sorry for bringing up this old thread, but it seems to be too aggressive
to stop scheduling further urbs on errors [1]. So is it possible for you
to re-test your usecase by reverting commit

    dbac5d07d13e ("usb: musb: host: don't start next rx urb if current one failed")

to see if only commit

    b5801212229f ("usb: musb: host: clear rxcsr error bit if set")

itself solves your issue?

I know you have tested the patch in [2], which is similar to commit
b5801212229f, but tha latter doesn't have 'goto finish' which does dma
cleanup on errors, it makes more sense to me. But I'd like to have you
tested with reverting dbac5d07d13e to be sure.

[1] https://marc.info/?l=linux-usb&m=151689238420622&w=2
[2] https://marc.info/?l=linux-kernel&m=146185425805967&w=2

thanks,
-Bin.

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Maxim Uvarov]

[1] says that issue is with back ported driver to 3.12.10. Can the
latest kernel be tested on the same hw?

Maxim.

2018-01-25 18:45 GMT+03:00 Bin Liu <b-liu@ti.com>:
> Hi Yegor and Max,
>
> On Tue, May 03, 2016 at 04:25:58PM +0200, Yegor Yefremov wrote:
>> On Tue, May 3, 2016 at 3:48 PM, Bin Liu <b-liu@ti.com> wrote:
>> > Hi,
>> >
>> > On Tue, May 03, 2016 at 12:03:52PM +0200, Yegor Yefremov wrote:
>> >> On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
>> >> > Hi,
>> >> >
>> >> > On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
>> >> >
>> >> > [snip]
>> >> >
>> >> >> Hello Bin,
>> >> >>
>> >> >> yes, it also works with that reset and go to finish:
>> >> >>
>> >> >> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>> >> >> index c3d5fc9..8cd98e7 100644
>> >> >> --- a/drivers/usb/musb/musb_host.c
>> >> >> +++ b/drivers/usb/musb/musb_host.c
>> >> >> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>> >> >>                 status = -EPROTO;
>> >> >>                 musb_writeb(epio, MUSB_RXINTERVAL, 0);
>> >> >>
>> >> >> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>> >> >> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>> >> >> +
>> >> >> +               goto finish;
>> >> >>         } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>> >> >>
>> >> >>                 if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>> >> >>
>> >> >
>> >> > Thanks for testing it.
>> >>
>> >> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
>> >>
>> >> Bin, Max thanks for fixing this issue.
>> >>
>> >> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
>> >
>> > Thanks for testing.
>> >
>> > Can you please test the patch [1] instead? I'd like to use it as the
>> > fix.
>> >
>> > [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
>>
>> The patch behaves the same as the previous one.
>
> Sorry for bringing up this old thread, but it seems to be too aggressive
> to stop scheduling further urbs on errors [1]. So is it possible for you
> to re-test your usecase by reverting commit
>
>     dbac5d07d13e ("usb: musb: host: don't start next rx urb if current one failed")
>
> to see if only commit
>
>     b5801212229f ("usb: musb: host: clear rxcsr error bit if set")
>
> itself solves your issue?
>
> I know you have tested the patch in [2], which is similar to commit
> b5801212229f, but tha latter doesn't have 'goto finish' which does dma
> cleanup on errors, it makes more sense to me. But I'd like to have you
> tested with reverting dbac5d07d13e to be sure.
>
> [1] https://marc.info/?l=linux-usb&m=151689238420622&w=2
> [2] https://marc.info/?l=linux-kernel&m=146185425805967&w=2
>
> thanks,
> -Bin.
>



-- 
Best regards,
Maxim Uvarov

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Maxim,

On Thu, Jan 25, 2018 at 07:24:02PM +0300, Maxim Uvarov wrote:
> [1] says that issue is with back ported driver to 3.12.10. Can the
> latest kernel be tested on the same hw?

Agreed that it should be tested with the latest kernel. But my concern
now is if stopping scheduling urbs on errors is a right thing to do,
that is why I asked if you can re-test your usecase with reverting the
commit. I am unable to reproduce the original issue you had.

Thanks,
-Bin.

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Maxim Uvarov]

Bin,

I looked to my local git and code does not have this latest line "goto
finish".  It was tested without it and everything worked. Right now I
can not get access to that hardware to check with and without. But
only can confirm that without "goto finish" function works with bunch
of drivers (usb ethernet, hids, hdd).

Best regards,
Maxim.

2018-01-25 19:31 GMT+03:00 Bin Liu <b-liu@ti.com>:
> Maxim,
>
> On Thu, Jan 25, 2018 at 07:24:02PM +0300, Maxim Uvarov wrote:
>> [1] says that issue is with back ported driver to 3.12.10. Can the
>> latest kernel be tested on the same hw?
>
> Agreed that it should be tested with the latest kernel. But my concern
> now is if stopping scheduling urbs on errors is a right thing to do,
> that is why I asked if you can re-test your usecase with reverting the
> commit. I am unable to reproduce the original issue you had.
>
> Thanks,
> -Bin.



-- 
Best regards,
Maxim Uvarov

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Bin Liu]

Maxim,

On Fri, Jan 26, 2018 at 12:24:54PM +0300, Maxim Uvarov wrote:
> Bin,
> 
> I looked to my local git and code does not have this latest line "goto
> finish".  It was tested without it and everything worked. Right now I
> can not get access to that hardware to check with and without. But
> only can confirm that without "goto finish" function works with bunch
> of drivers (usb ethernet, hids, hdd).

Thanks for the confirmation. The revert patch has been sent out.

Regards,
-Bin.

> 
> Best regards,
> Maxim.
> 
> 2018-01-25 19:31 GMT+03:00 Bin Liu <b-liu@ti.com>:
> > Maxim,
> >
> > On Thu, Jan 25, 2018 at 07:24:02PM +0300, Maxim Uvarov wrote:
> >> [1] says that issue is with back ported driver to 3.12.10. Can the
> >> latest kernel be tested on the same hw?
> >
> > Agreed that it should be tested with the latest kernel. But my concern
> > now is if stopping scheduling urbs on errors is a right thing to do,
> > that is why I asked if you can re-test your usecase with reverting the
> > commit. I am unable to reproduce the original issue you had.
> >
> > Thanks,
> > -Bin.
> 
> 
> 
> -- 
> Best regards,
> Maxim Uvarov

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Tomas Paukrt]

Hi Maxim,

unfortunately we cannot test the latest kernel right now, because we 
have custom drivers and additional changes that need to be ported, but 
the MUSB driver in our kernel should contain all fixes from 
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/log/drivers/usb/musb

Best regards

Tomas


Dne 25.1.2018 v 17:24 Maxim Uvarov napsal(a):
> [1] says that issue is with back ported driver to 3.12.10. Can the
> latest kernel be tested on the same hw?
>
> Maxim.
>
> 2018-01-25 18:45 GMT+03:00 Bin Liu <b-liu@ti.com>:
>> Hi Yegor and Max,
>>
>> On Tue, May 03, 2016 at 04:25:58PM +0200, Yegor Yefremov wrote:
>>> On Tue, May 3, 2016 at 3:48 PM, Bin Liu <b-liu@ti.com> wrote:
>>>> Hi,
>>>>
>>>> On Tue, May 03, 2016 at 12:03:52PM +0200, Yegor Yefremov wrote:
>>>>> On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
>>>>>> Hi,
>>>>>>
>>>>>> On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
>>>>>>
>>>>>> [snip]
>>>>>>
>>>>>>> Hello Bin,
>>>>>>>
>>>>>>> yes, it also works with that reset and go to finish:
>>>>>>>
>>>>>>> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
>>>>>>> index c3d5fc9..8cd98e7 100644
>>>>>>> --- a/drivers/usb/musb/musb_host.c
>>>>>>> +++ b/drivers/usb/musb/musb_host.c
>>>>>>> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 epnum)
>>>>>>>                  status = -EPROTO;
>>>>>>>                  musb_writeb(epio, MUSB_RXINTERVAL, 0);
>>>>>>>
>>>>>>> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>>>>>>> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>>>>>>> +
>>>>>>> +               goto finish;
>>>>>>>          } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>>>>>>>
>>>>>>>                  if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>>>>>>>
>>>>>> Thanks for testing it.
>>>>> Have tested your patch and now both FT4232 and Huawei don't freeze on removal.
>>>>>
>>>>> Bin, Max thanks for fixing this issue.
>>>>>
>>>>> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
>>>> Thanks for testing.
>>>>
>>>> Can you please test the patch [1] instead? I'd like to use it as the
>>>> fix.
>>>>
>>>> [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
>>> The patch behaves the same as the previous one.
>> Sorry for bringing up this old thread, but it seems to be too aggressive
>> to stop scheduling further urbs on errors [1]. So is it possible for you
>> to re-test your usecase by reverting commit
>>
>>      dbac5d07d13e ("usb: musb: host: don't start next rx urb if current one failed")
>>
>> to see if only commit
>>
>>      b5801212229f ("usb: musb: host: clear rxcsr error bit if set")
>>
>> itself solves your issue?
>>
>> I know you have tested the patch in [2], which is similar to commit
>> b5801212229f, but tha latter doesn't have 'goto finish' which does dma
>> cleanup on errors, it makes more sense to me. But I'd like to have you
>> tested with reverting dbac5d07d13e to be sure.
>>
>> [1] https://marc.info/?l=linux-usb&m=151689238420622&w=2
>> [2] https://marc.info/?l=linux-kernel&m=146185425805967&w=2
>>
>> thanks,
>> -Bin.
>>
>
>

Re: [PATCHv2] musb_host: fix lockup on rxcsr_h_error

[Tomas Paukrt]

Hi Maxim and Bin,

I would like to reopen this issue, because we have moved to 4.12.24 and 
restarting two cellular modules using AT+CFUN=1,1 command at the same 
time leads to system freeze, because RX ISR is repeatedly invoked. Maybe 
*musb_start_urb* should be always called from *musb_advance_schedule* 
after a random communication error, but should not be called repeatedly 
if the device has been disconnected.

Best regards

Tomas


Dne 26.1.2018 v 11:42 Tomas Paukrt napsal(a):
> Hi Maxim,
>
> unfortunately we cannot test the latest kernel right now, because we 
> have custom drivers and additional changes that need to be ported, but 
> the MUSB driver in our kernel should contain all fixes from 
> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/log/drivers/usb/musb
>
> Best regards
>
> Tomas
>
>
> Dne 25.1.2018 v 17:24 Maxim Uvarov napsal(a):
>> [1] says that issue is with back ported driver to 3.12.10. Can the
>> latest kernel be tested on the same hw?
>>
>> Maxim.
>>
>> 2018-01-25 18:45 GMT+03:00 Bin Liu <b-liu@ti.com>:
>>> Hi Yegor and Max,
>>>
>>> On Tue, May 03, 2016 at 04:25:58PM +0200, Yegor Yefremov wrote:
>>>> On Tue, May 3, 2016 at 3:48 PM, Bin Liu <b-liu@ti.com> wrote:
>>>>> Hi,
>>>>>
>>>>> On Tue, May 03, 2016 at 12:03:52PM +0200, Yegor Yefremov wrote:
>>>>>> On Thu, Apr 28, 2016 at 4:37 PM, Bin Liu <b-liu@ti.com> wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> On Thu, Apr 28, 2016 at 09:51:37AM +0300, Maxim Uvarov wrote:
>>>>>>>
>>>>>>> [snip]
>>>>>>>
>>>>>>>> Hello Bin,
>>>>>>>>
>>>>>>>> yes, it also works with that reset and go to finish:
>>>>>>>>
>>>>>>>> diff --git a/drivers/usb/musb/musb_host.c 
>>>>>>>> b/drivers/usb/musb/musb_host.c
>>>>>>>> index c3d5fc9..8cd98e7 100644
>>>>>>>> --- a/drivers/usb/musb/musb_host.c
>>>>>>>> +++ b/drivers/usb/musb/musb_host.c
>>>>>>>> @@ -1599,6 +1599,10 @@ void musb_host_rx(struct musb *musb, u8 
>>>>>>>> epnum)
>>>>>>>>                  status = -EPROTO;
>>>>>>>>                  musb_writeb(epio, MUSB_RXINTERVAL, 0);
>>>>>>>>
>>>>>>>> +               rx_csr &= ~MUSB_RXCSR_H_ERROR;
>>>>>>>> +               musb_writew(epio, MUSB_RXCSR, rx_csr);
>>>>>>>> +
>>>>>>>> +               goto finish;
>>>>>>>>          } else if (rx_csr & MUSB_RXCSR_DATAERROR) {
>>>>>>>>
>>>>>>>>                  if (USB_ENDPOINT_XFER_ISOC != qh->type) {
>>>>>>>>
>>>>>>> Thanks for testing it.
>>>>>> Have tested your patch and now both FT4232 and Huawei don't 
>>>>>> freeze on removal.
>>>>>>
>>>>>> Bin, Max thanks for fixing this issue.
>>>>>>
>>>>>> Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
>>>>> Thanks for testing.
>>>>>
>>>>> Can you please test the patch [1] instead? I'd like to use it as the
>>>>> fix.
>>>>>
>>>>> [1] http://marc.info/?l=linux-usb&m=146222355213935&w=2
>>>> The patch behaves the same as the previous one.
>>> Sorry for bringing up this old thread, but it seems to be too 
>>> aggressive
>>> to stop scheduling further urbs on errors [1]. So is it possible for 
>>> you
>>> to re-test your usecase by reverting commit
>>>
>>>      dbac5d07d13e ("usb: musb: host: don't start next rx urb if 
>>> current one failed")
>>>
>>> to see if only commit
>>>
>>>      b5801212229f ("usb: musb: host: clear rxcsr error bit if set")
>>>
>>> itself solves your issue?
>>>
>>> I know you have tested the patch in [2], which is similar to commit
>>> b5801212229f, but tha latter doesn't have 'goto finish' which does dma
>>> cleanup on errors, it makes more sense to me. But I'd like to have you
>>> tested with reverting dbac5d07d13e to be sure.
>>>
>>> [1] https://marc.info/?l=linux-usb&m=151689238420622&w=2
>>> [2] https://marc.info/?l=linux-kernel&m=146185425805967&w=2
>>>
>>> thanks,
>>> -Bin.
>>>
>>
>>
>