Re: [PATCH 11/18] spi: qup: properly detect extra interrupts

[Sricharan R]

Hi Andy,

On 6/15/2017 1:29 AM, Andy Gross wrote:
> On Wed, Jun 14, 2017 at 12:57:25PM +0530, Sricharan R wrote:
>> Hi Varada,
>>
>> On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
>>> It's possible for a SPI transaction to complete and get another
>>> interrupt and have it processed on the same spi_transfer before the
>>> transfer_one can set it to NULL.
>>>
>>> This masks unexpected interrupts, so let's set the spi_transfer to
>>> NULL in the interrupt once the transaction is done. So we can
>>> properly detect these bad interrupts and print warning messages.
>>>
>>> Signed-off-by: Matthew McClintock 
>>> Signed-off-by: Varadarajan Narayanan 
>>> ---
>>>  drivers/spi/spi-qup.c | 20 +++-
>>>  1 file changed, 11 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
>>> index bd53e82..1a2a9d9 100644
>>> --- a/drivers/spi/spi-qup.c
>>> +++ b/drivers/spi/spi-qup.c
>>> @@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
>>> *dev_id)
>>> struct spi_qup *controller = dev_id;
>>> struct spi_transfer *xfer;
>>> u32 opflags, qup_err, spi_err;
>>> -   unsigned long flags;
>>> int error = 0;
>>> +   bool done = 0;
>>>  
>>> -   spin_lock_irqsave(>lock, flags);
>>> +   spin_lock(>lock);
>>> xfer = controller->xfer;
>>> controller->xfer = NULL;
>>> -   spin_unlock_irqrestore(>lock, flags);
>>> +   spin_unlock(>lock);
>>
>>  Why change the locking here ?
>>
>>>  
>>> qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
>>> spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
>>> @@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
>>> *dev_id)
>>> spi_qup_write(controller, xfer);
>>> }
>>>  
>>> -   spin_lock_irqsave(>lock, flags);
>>> -   controller->error = error;
>>> -   controller->xfer = xfer;
>>> -   spin_unlock_irqrestore(>lock, flags);
>>> -
>>> /* re-read opflags as flags may have changed due to actions above */
>>> opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
>>>  
>>> if ((controller->rx_bytes == xfer->len &&
>>> (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
>>> +   done = true;
>>> +
>>> +   spin_lock(>lock);
>>> +   controller->error = error;
>>> +   controller->xfer = done ? NULL : xfer;
>>> +   spin_unlock(>lock);
>>> +
>>> +   if (done)
>>> complete(>done);
>>>  
>>   Its not clear, why the driver is setting the controller->xfer = NULL
>>   and restoring it inside the irq. This patch seems to fix things on
>>   top of that.
> 
> I think the original intent was to make sure that the irqhandler knew that 
> there
> was no outstanding transaction.  This begs the question of why that would ever
> be necessary.  I think it would suffice to rework all of that to remove that
> behavior and perhaps enable/disable the irq as we need to during transactions.
> 
> I've never been a fan of the controller->xfer being set to NULL.

 Agree, that part needs fixing in the original code. Also patch #10 changing the
 behavior to acknowledge the interrupts only when its spurious does not look
 correct. Trying to fix the original should simplify or avoid the spurious case
 itself.

Regards,
 Sricharan 

-- 
"QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of 
Code Aurora Forum, hosted by The Linux Foundation

Re: [PATCH 11/18] spi: qup: properly detect extra interrupts

[Sricharan R]

Hi Andy,

On 6/15/2017 1:29 AM, Andy Gross wrote:
> On Wed, Jun 14, 2017 at 12:57:25PM +0530, Sricharan R wrote:
>> Hi Varada,
>>
>> On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
>>> It's possible for a SPI transaction to complete and get another
>>> interrupt and have it processed on the same spi_transfer before the
>>> transfer_one can set it to NULL.
>>>
>>> This masks unexpected interrupts, so let's set the spi_transfer to
>>> NULL in the interrupt once the transaction is done. So we can
>>> properly detect these bad interrupts and print warning messages.
>>>
>>> Signed-off-by: Matthew McClintock 
>>> Signed-off-by: Varadarajan Narayanan 
>>> ---
>>>  drivers/spi/spi-qup.c | 20 +++-
>>>  1 file changed, 11 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
>>> index bd53e82..1a2a9d9 100644
>>> --- a/drivers/spi/spi-qup.c
>>> +++ b/drivers/spi/spi-qup.c
>>> @@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
>>> *dev_id)
>>> struct spi_qup *controller = dev_id;
>>> struct spi_transfer *xfer;
>>> u32 opflags, qup_err, spi_err;
>>> -   unsigned long flags;
>>> int error = 0;
>>> +   bool done = 0;
>>>  
>>> -   spin_lock_irqsave(>lock, flags);
>>> +   spin_lock(>lock);
>>> xfer = controller->xfer;
>>> controller->xfer = NULL;
>>> -   spin_unlock_irqrestore(>lock, flags);
>>> +   spin_unlock(>lock);
>>
>>  Why change the locking here ?
>>
>>>  
>>> qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
>>> spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
>>> @@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
>>> *dev_id)
>>> spi_qup_write(controller, xfer);
>>> }
>>>  
>>> -   spin_lock_irqsave(>lock, flags);
>>> -   controller->error = error;
>>> -   controller->xfer = xfer;
>>> -   spin_unlock_irqrestore(>lock, flags);
>>> -
>>> /* re-read opflags as flags may have changed due to actions above */
>>> opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
>>>  
>>> if ((controller->rx_bytes == xfer->len &&
>>> (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
>>> +   done = true;
>>> +
>>> +   spin_lock(>lock);
>>> +   controller->error = error;
>>> +   controller->xfer = done ? NULL : xfer;
>>> +   spin_unlock(>lock);
>>> +
>>> +   if (done)
>>> complete(>done);
>>>  
>>   Its not clear, why the driver is setting the controller->xfer = NULL
>>   and restoring it inside the irq. This patch seems to fix things on
>>   top of that.
> 
> I think the original intent was to make sure that the irqhandler knew that 
> there
> was no outstanding transaction.  This begs the question of why that would ever
> be necessary.  I think it would suffice to rework all of that to remove that
> behavior and perhaps enable/disable the irq as we need to during transactions.
> 
> I've never been a fan of the controller->xfer being set to NULL.

 Agree, that part needs fixing in the original code. Also patch #10 changing the
 behavior to acknowledge the interrupts only when its spurious does not look
 correct. Trying to fix the original should simplify or avoid the spurious case
 itself.

Regards,
 Sricharan 

-- 
"QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of 
Code Aurora Forum, hosted by The Linux Foundation

Re: [PATCH 11/18] spi: qup: properly detect extra interrupts

[Matthew McClintock]

On Wed, Jun 14, 2017 at 2:59 PM, Andy Gross  wrote:
> On Wed, Jun 14, 2017 at 12:57:25PM +0530, Sricharan R wrote:
>> Hi Varada,
>>
>> On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
>> > It's possible for a SPI transaction to complete and get another
>> > interrupt and have it processed on the same spi_transfer before the
>> > transfer_one can set it to NULL.
>> >
>> > This masks unexpected interrupts, so let's set the spi_transfer to
>> > NULL in the interrupt once the transaction is done. So we can
>> > properly detect these bad interrupts and print warning messages.
>> >
>> > Signed-off-by: Matthew McClintock 
>> > Signed-off-by: Varadarajan Narayanan 
>> > ---
>> >  drivers/spi/spi-qup.c | 20 +++-
>> >  1 file changed, 11 insertions(+), 9 deletions(-)
>> >
>> > diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
>> > index bd53e82..1a2a9d9 100644
>> > --- a/drivers/spi/spi-qup.c
>> > +++ b/drivers/spi/spi-qup.c
>> > @@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
>> > *dev_id)
>> > struct spi_qup *controller = dev_id;
>> > struct spi_transfer *xfer;
>> > u32 opflags, qup_err, spi_err;
>> > -   unsigned long flags;
>> > int error = 0;
>> > +   bool done = 0;
>> >
>> > -   spin_lock_irqsave(>lock, flags);
>> > +   spin_lock(>lock);
>> > xfer = controller->xfer;
>> > controller->xfer = NULL;
>> > -   spin_unlock_irqrestore(>lock, flags);
>> > +   spin_unlock(>lock);
>>
>>  Why change the locking here ?
>>
>> >
>> > qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
>> > spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
>> > @@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
>> > *dev_id)
>> > spi_qup_write(controller, xfer);
>> > }
>> >
>> > -   spin_lock_irqsave(>lock, flags);
>> > -   controller->error = error;
>> > -   controller->xfer = xfer;
>> > -   spin_unlock_irqrestore(>lock, flags);
>> > -
>> > /* re-read opflags as flags may have changed due to actions above */
>> > opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
>> >
>> > if ((controller->rx_bytes == xfer->len &&
>> > (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
>> > +   done = true;
>> > +
>> > +   spin_lock(>lock);
>> > +   controller->error = error;
>> > +   controller->xfer = done ? NULL : xfer;
>> > +   spin_unlock(>lock);
>> > +
>> > +   if (done)
>> > complete(>done);
>> >
>>   Its not clear, why the driver is setting the controller->xfer = NULL
>>   and restoring it inside the irq. This patch seems to fix things on
>>   top of that.
>
> I think the original intent was to make sure that the irqhandler knew that 
> there
> was no outstanding transaction.  This begs the question of why that would ever
> be necessary.  I think it would suffice to rework all of that to remove that
> behavior and perhaps enable/disable the irq as we need to during transactions.
>
> I've never been a fan of the controller->xfer being set to NULL.

Also, this patch presumably fixes an issue seen on Dakota SoCs,
doesn't add or remote the NULL bits.

-M

Re: [PATCH 11/18] spi: qup: properly detect extra interrupts

[Matthew McClintock]

On Wed, Jun 14, 2017 at 2:59 PM, Andy Gross  wrote:
> On Wed, Jun 14, 2017 at 12:57:25PM +0530, Sricharan R wrote:
>> Hi Varada,
>>
>> On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
>> > It's possible for a SPI transaction to complete and get another
>> > interrupt and have it processed on the same spi_transfer before the
>> > transfer_one can set it to NULL.
>> >
>> > This masks unexpected interrupts, so let's set the spi_transfer to
>> > NULL in the interrupt once the transaction is done. So we can
>> > properly detect these bad interrupts and print warning messages.
>> >
>> > Signed-off-by: Matthew McClintock 
>> > Signed-off-by: Varadarajan Narayanan 
>> > ---
>> >  drivers/spi/spi-qup.c | 20 +++-
>> >  1 file changed, 11 insertions(+), 9 deletions(-)
>> >
>> > diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
>> > index bd53e82..1a2a9d9 100644
>> > --- a/drivers/spi/spi-qup.c
>> > +++ b/drivers/spi/spi-qup.c
>> > @@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
>> > *dev_id)
>> > struct spi_qup *controller = dev_id;
>> > struct spi_transfer *xfer;
>> > u32 opflags, qup_err, spi_err;
>> > -   unsigned long flags;
>> > int error = 0;
>> > +   bool done = 0;
>> >
>> > -   spin_lock_irqsave(>lock, flags);
>> > +   spin_lock(>lock);
>> > xfer = controller->xfer;
>> > controller->xfer = NULL;
>> > -   spin_unlock_irqrestore(>lock, flags);
>> > +   spin_unlock(>lock);
>>
>>  Why change the locking here ?
>>
>> >
>> > qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
>> > spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
>> > @@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
>> > *dev_id)
>> > spi_qup_write(controller, xfer);
>> > }
>> >
>> > -   spin_lock_irqsave(>lock, flags);
>> > -   controller->error = error;
>> > -   controller->xfer = xfer;
>> > -   spin_unlock_irqrestore(>lock, flags);
>> > -
>> > /* re-read opflags as flags may have changed due to actions above */
>> > opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
>> >
>> > if ((controller->rx_bytes == xfer->len &&
>> > (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
>> > +   done = true;
>> > +
>> > +   spin_lock(>lock);
>> > +   controller->error = error;
>> > +   controller->xfer = done ? NULL : xfer;
>> > +   spin_unlock(>lock);
>> > +
>> > +   if (done)
>> > complete(>done);
>> >
>>   Its not clear, why the driver is setting the controller->xfer = NULL
>>   and restoring it inside the irq. This patch seems to fix things on
>>   top of that.
>
> I think the original intent was to make sure that the irqhandler knew that 
> there
> was no outstanding transaction.  This begs the question of why that would ever
> be necessary.  I think it would suffice to rework all of that to remove that
> behavior and perhaps enable/disable the irq as we need to during transactions.
>
> I've never been a fan of the controller->xfer being set to NULL.

Also, this patch presumably fixes an issue seen on Dakota SoCs,
doesn't add or remote the NULL bits.

-M

Re: [PATCH 11/18] spi: qup: properly detect extra interrupts

[Andy Gross]

On Wed, Jun 14, 2017 at 12:57:25PM +0530, Sricharan R wrote:
> Hi Varada,
> 
> On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
> > It's possible for a SPI transaction to complete and get another
> > interrupt and have it processed on the same spi_transfer before the
> > transfer_one can set it to NULL.
> > 
> > This masks unexpected interrupts, so let's set the spi_transfer to
> > NULL in the interrupt once the transaction is done. So we can
> > properly detect these bad interrupts and print warning messages.
> > 
> > Signed-off-by: Matthew McClintock 
> > Signed-off-by: Varadarajan Narayanan 
> > ---
> >  drivers/spi/spi-qup.c | 20 +++-
> >  1 file changed, 11 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
> > index bd53e82..1a2a9d9 100644
> > --- a/drivers/spi/spi-qup.c
> > +++ b/drivers/spi/spi-qup.c
> > @@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
> > *dev_id)
> > struct spi_qup *controller = dev_id;
> > struct spi_transfer *xfer;
> > u32 opflags, qup_err, spi_err;
> > -   unsigned long flags;
> > int error = 0;
> > +   bool done = 0;
> >  
> > -   spin_lock_irqsave(>lock, flags);
> > +   spin_lock(>lock);
> > xfer = controller->xfer;
> > controller->xfer = NULL;
> > -   spin_unlock_irqrestore(>lock, flags);
> > +   spin_unlock(>lock);
> 
>  Why change the locking here ?
> 
> >  
> > qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
> > spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
> > @@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
> > *dev_id)
> > spi_qup_write(controller, xfer);
> > }
> >  
> > -   spin_lock_irqsave(>lock, flags);
> > -   controller->error = error;
> > -   controller->xfer = xfer;
> > -   spin_unlock_irqrestore(>lock, flags);
> > -
> > /* re-read opflags as flags may have changed due to actions above */
> > opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
> >  
> > if ((controller->rx_bytes == xfer->len &&
> > (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
> > +   done = true;
> > +
> > +   spin_lock(>lock);
> > +   controller->error = error;
> > +   controller->xfer = done ? NULL : xfer;
> > +   spin_unlock(>lock);
> > +
> > +   if (done)
> > complete(>done);
> >  
>   Its not clear, why the driver is setting the controller->xfer = NULL
>   and restoring it inside the irq. This patch seems to fix things on
>   top of that.

I think the original intent was to make sure that the irqhandler knew that there
was no outstanding transaction.  This begs the question of why that would ever
be necessary.  I think it would suffice to rework all of that to remove that
behavior and perhaps enable/disable the irq as we need to during transactions.

I've never been a fan of the controller->xfer being set to NULL.


Regards,

Andy

Re: [PATCH 11/18] spi: qup: properly detect extra interrupts

[Andy Gross]

On Wed, Jun 14, 2017 at 12:57:25PM +0530, Sricharan R wrote:
> Hi Varada,
> 
> On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
> > It's possible for a SPI transaction to complete and get another
> > interrupt and have it processed on the same spi_transfer before the
> > transfer_one can set it to NULL.
> > 
> > This masks unexpected interrupts, so let's set the spi_transfer to
> > NULL in the interrupt once the transaction is done. So we can
> > properly detect these bad interrupts and print warning messages.
> > 
> > Signed-off-by: Matthew McClintock 
> > Signed-off-by: Varadarajan Narayanan 
> > ---
> >  drivers/spi/spi-qup.c | 20 +++-
> >  1 file changed, 11 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
> > index bd53e82..1a2a9d9 100644
> > --- a/drivers/spi/spi-qup.c
> > +++ b/drivers/spi/spi-qup.c
> > @@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
> > *dev_id)
> > struct spi_qup *controller = dev_id;
> > struct spi_transfer *xfer;
> > u32 opflags, qup_err, spi_err;
> > -   unsigned long flags;
> > int error = 0;
> > +   bool done = 0;
> >  
> > -   spin_lock_irqsave(>lock, flags);
> > +   spin_lock(>lock);
> > xfer = controller->xfer;
> > controller->xfer = NULL;
> > -   spin_unlock_irqrestore(>lock, flags);
> > +   spin_unlock(>lock);
> 
>  Why change the locking here ?
> 
> >  
> > qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
> > spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
> > @@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
> > *dev_id)
> > spi_qup_write(controller, xfer);
> > }
> >  
> > -   spin_lock_irqsave(>lock, flags);
> > -   controller->error = error;
> > -   controller->xfer = xfer;
> > -   spin_unlock_irqrestore(>lock, flags);
> > -
> > /* re-read opflags as flags may have changed due to actions above */
> > opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
> >  
> > if ((controller->rx_bytes == xfer->len &&
> > (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
> > +   done = true;
> > +
> > +   spin_lock(>lock);
> > +   controller->error = error;
> > +   controller->xfer = done ? NULL : xfer;
> > +   spin_unlock(>lock);
> > +
> > +   if (done)
> > complete(>done);
> >  
>   Its not clear, why the driver is setting the controller->xfer = NULL
>   and restoring it inside the irq. This patch seems to fix things on
>   top of that.

I think the original intent was to make sure that the irqhandler knew that there
was no outstanding transaction.  This begs the question of why that would ever
be necessary.  I think it would suffice to rework all of that to remove that
behavior and perhaps enable/disable the irq as we need to during transactions.

I've never been a fan of the controller->xfer being set to NULL.


Regards,

Andy

Re: [PATCH 11/18] spi: qup: properly detect extra interrupts

[Sricharan R]

Hi Varada,

On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
> It's possible for a SPI transaction to complete and get another
> interrupt and have it processed on the same spi_transfer before the
> transfer_one can set it to NULL.
> 
> This masks unexpected interrupts, so let's set the spi_transfer to
> NULL in the interrupt once the transaction is done. So we can
> properly detect these bad interrupts and print warning messages.
> 
> Signed-off-by: Matthew McClintock 
> Signed-off-by: Varadarajan Narayanan 
> ---
>  drivers/spi/spi-qup.c | 20 +++-
>  1 file changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
> index bd53e82..1a2a9d9 100644
> --- a/drivers/spi/spi-qup.c
> +++ b/drivers/spi/spi-qup.c
> @@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
> *dev_id)
>   struct spi_qup *controller = dev_id;
>   struct spi_transfer *xfer;
>   u32 opflags, qup_err, spi_err;
> - unsigned long flags;
>   int error = 0;
> + bool done = 0;
>  
> - spin_lock_irqsave(>lock, flags);
> + spin_lock(>lock);
>   xfer = controller->xfer;
>   controller->xfer = NULL;
> - spin_unlock_irqrestore(>lock, flags);
> + spin_unlock(>lock);

 Why change the locking here ?

>  
>   qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
>   spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
> @@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
> *dev_id)
>   spi_qup_write(controller, xfer);
>   }
>  
> - spin_lock_irqsave(>lock, flags);
> - controller->error = error;
> - controller->xfer = xfer;
> - spin_unlock_irqrestore(>lock, flags);
> -
>   /* re-read opflags as flags may have changed due to actions above */
>   opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
>  
>   if ((controller->rx_bytes == xfer->len &&
>   (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
> + done = true;
> +
> + spin_lock(>lock);
> + controller->error = error;
> + controller->xfer = done ? NULL : xfer;
> + spin_unlock(>lock);
> +
> + if (done)
>   complete(>done);
>  
  Its not clear, why the driver is setting the controller->xfer = NULL
  and restoring it inside the irq. This patch seems to fix things on
  top of that.

Regards,
 Sricharan

-- 
"QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of 
Code Aurora Forum, hosted by The Linux Foundation

Re: [PATCH 11/18] spi: qup: properly detect extra interrupts

[Sricharan R]

Hi Varada,

On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
> It's possible for a SPI transaction to complete and get another
> interrupt and have it processed on the same spi_transfer before the
> transfer_one can set it to NULL.
> 
> This masks unexpected interrupts, so let's set the spi_transfer to
> NULL in the interrupt once the transaction is done. So we can
> properly detect these bad interrupts and print warning messages.
> 
> Signed-off-by: Matthew McClintock 
> Signed-off-by: Varadarajan Narayanan 
> ---
>  drivers/spi/spi-qup.c | 20 +++-
>  1 file changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
> index bd53e82..1a2a9d9 100644
> --- a/drivers/spi/spi-qup.c
> +++ b/drivers/spi/spi-qup.c
> @@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
> *dev_id)
>   struct spi_qup *controller = dev_id;
>   struct spi_transfer *xfer;
>   u32 opflags, qup_err, spi_err;
> - unsigned long flags;
>   int error = 0;
> + bool done = 0;
>  
> - spin_lock_irqsave(>lock, flags);
> + spin_lock(>lock);
>   xfer = controller->xfer;
>   controller->xfer = NULL;
> - spin_unlock_irqrestore(>lock, flags);
> + spin_unlock(>lock);

 Why change the locking here ?

>  
>   qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
>   spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
> @@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void 
> *dev_id)
>   spi_qup_write(controller, xfer);
>   }
>  
> - spin_lock_irqsave(>lock, flags);
> - controller->error = error;
> - controller->xfer = xfer;
> - spin_unlock_irqrestore(>lock, flags);
> -
>   /* re-read opflags as flags may have changed due to actions above */
>   opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
>  
>   if ((controller->rx_bytes == xfer->len &&
>   (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
> + done = true;
> +
> + spin_lock(>lock);
> + controller->error = error;
> + controller->xfer = done ? NULL : xfer;
> + spin_unlock(>lock);
> +
> + if (done)
>   complete(>done);
>  
  Its not clear, why the driver is setting the controller->xfer = NULL
  and restoring it inside the irq. This patch seems to fix things on
  top of that.

Regards,
 Sricharan

-- 
"QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of 
Code Aurora Forum, hosted by The Linux Foundation

[PATCH 11/18] spi: qup: properly detect extra interrupts

[Varadarajan Narayanan]

It's possible for a SPI transaction to complete and get another
interrupt and have it processed on the same spi_transfer before the
transfer_one can set it to NULL.

This masks unexpected interrupts, so let's set the spi_transfer to
NULL in the interrupt once the transaction is done. So we can
properly detect these bad interrupts and print warning messages.

Signed-off-by: Matthew McClintock 
Signed-off-by: Varadarajan Narayanan 
---
 drivers/spi/spi-qup.c | 20 +++-
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
index bd53e82..1a2a9d9 100644
--- a/drivers/spi/spi-qup.c
+++ b/drivers/spi/spi-qup.c
@@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
struct spi_qup *controller = dev_id;
struct spi_transfer *xfer;
u32 opflags, qup_err, spi_err;
-   unsigned long flags;
int error = 0;
+   bool done = 0;
 
-   spin_lock_irqsave(>lock, flags);
+   spin_lock(>lock);
xfer = controller->xfer;
controller->xfer = NULL;
-   spin_unlock_irqrestore(>lock, flags);
+   spin_unlock(>lock);
 
qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
@@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
spi_qup_write(controller, xfer);
}
 
-   spin_lock_irqsave(>lock, flags);
-   controller->error = error;
-   controller->xfer = xfer;
-   spin_unlock_irqrestore(>lock, flags);
-
/* re-read opflags as flags may have changed due to actions above */
opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
 
if ((controller->rx_bytes == xfer->len &&
(opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
+   done = true;
+
+   spin_lock(>lock);
+   controller->error = error;
+   controller->xfer = done ? NULL : xfer;
+   spin_unlock(>lock);
+
+   if (done)
complete(>done);
 
return IRQ_HANDLED;
@@ -765,7 +768,6 @@ static int spi_qup_transfer_one(struct spi_master *master,
 exit:
spi_qup_set_state(controller, QUP_STATE_RESET);
spin_lock_irqsave(>lock, flags);
-   controller->xfer = NULL;
if (!ret)
ret = controller->error;
spin_unlock_irqrestore(>lock, flags);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of 
Code Aurora Forum, hosted by The Linux Foundation

[PATCH 11/18] spi: qup: properly detect extra interrupts

[Varadarajan Narayanan]

It's possible for a SPI transaction to complete and get another
interrupt and have it processed on the same spi_transfer before the
transfer_one can set it to NULL.

This masks unexpected interrupts, so let's set the spi_transfer to
NULL in the interrupt once the transaction is done. So we can
properly detect these bad interrupts and print warning messages.

Signed-off-by: Matthew McClintock 
Signed-off-by: Varadarajan Narayanan 
---
 drivers/spi/spi-qup.c | 20 +++-
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
index bd53e82..1a2a9d9 100644
--- a/drivers/spi/spi-qup.c
+++ b/drivers/spi/spi-qup.c
@@ -496,13 +496,13 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
struct spi_qup *controller = dev_id;
struct spi_transfer *xfer;
u32 opflags, qup_err, spi_err;
-   unsigned long flags;
int error = 0;
+   bool done = 0;
 
-   spin_lock_irqsave(>lock, flags);
+   spin_lock(>lock);
xfer = controller->xfer;
controller->xfer = NULL;
-   spin_unlock_irqrestore(>lock, flags);
+   spin_unlock(>lock);
 
qup_err = readl_relaxed(controller->base + QUP_ERROR_FLAGS);
spi_err = readl_relaxed(controller->base + SPI_ERROR_FLAGS);
@@ -556,16 +556,19 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
spi_qup_write(controller, xfer);
}
 
-   spin_lock_irqsave(>lock, flags);
-   controller->error = error;
-   controller->xfer = xfer;
-   spin_unlock_irqrestore(>lock, flags);
-
/* re-read opflags as flags may have changed due to actions above */
opflags = readl_relaxed(controller->base + QUP_OPERATIONAL);
 
if ((controller->rx_bytes == xfer->len &&
(opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) ||  error)
+   done = true;
+
+   spin_lock(>lock);
+   controller->error = error;
+   controller->xfer = done ? NULL : xfer;
+   spin_unlock(>lock);
+
+   if (done)
complete(>done);
 
return IRQ_HANDLED;
@@ -765,7 +768,6 @@ static int spi_qup_transfer_one(struct spi_master *master,
 exit:
spi_qup_set_state(controller, QUP_STATE_RESET);
spin_lock_irqsave(>lock, flags);
-   controller->xfer = NULL;
if (!ret)
ret = controller->error;
spin_unlock_irqrestore(>lock, flags);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of 
Code Aurora Forum, hosted by The Linux Foundation