diff mbox

[10/18] spi: qup: Fix DMA mode interrupt handling

Message ID 1497419551-21834-11-git-send-email-varada@codeaurora.org (mailing list archive)
State New, archived
Headers show

Commit Message

Varadarajan Narayanan June 14, 2017, 5:52 a.m. UTC
This is needed for v1, where the i/o completion is not
handled in the dma driver.

Signed-off-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Varadarajan Narayanan <varada@codeaurora.org>
---
 drivers/spi/spi-qup.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

Comments

Sricharan Ramabadhran June 14, 2017, 7:21 a.m. UTC | #1
Hi Varada,

On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
> This is needed for v1, where the i/o completion is not
> handled in the dma driver.
> 
> Signed-off-by: Andy Gross <andy.gross@linaro.org>
> Signed-off-by: Varadarajan Narayanan <varada@codeaurora.org>
> ---
>  drivers/spi/spi-qup.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
> index 872de28..bd53e82 100644
> --- a/drivers/spi/spi-qup.c
> +++ b/drivers/spi/spi-qup.c
> @@ -510,9 +510,9 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
>  
>  	writel_relaxed(qup_err, controller->base + QUP_ERROR_FLAGS);
>  	writel_relaxed(spi_err, controller->base + SPI_ERROR_FLAGS);
> -	writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
>  
>  	if (!xfer) {
> +		writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);

 This does look correct to remove acknowledging the QUP in normal case and
  do it conditionally only when xfer = NULL.

>  		dev_err_ratelimited(controller->dev, "unexpected irq %08x %08x %08x\n",
>  				    qup_err, spi_err, opflags);
>  		return IRQ_HANDLED;
> @@ -540,7 +540,15 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
>  		error = -EIO;
>  	}
>  
> -	if (!spi_qup_is_dma_xfer(controller->mode)) {
> +	if (spi_qup_is_dma_xfer(controller->mode)) {
> +		writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
> +		if (opflags & QUP_OP_IN_SERVICE_FLAG &&
> +		    opflags & QUP_OP_MAX_INPUT_DONE_FLAG)
> +			complete(&controller->rxc);
> +		if (opflags & QUP_OP_OUT_SERVICE_FLAG &&
> +		    opflags & QUP_OP_MAX_OUTPUT_DONE_FLAG)
> +			complete(&controller->txc);
> +	} else {

 Is this because in patch #8 that we do not populate the dma callback
 for v1. If that is done, this should not be required at all, as the
 complete would be signalled from the dma callback.

Regards,
 Sricharan
Andy Gross June 14, 2017, 8:06 p.m. UTC | #2
On Wed, Jun 14, 2017 at 12:51:11PM +0530, Sricharan R wrote:
> Hi Varada,
> 
> On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
> > This is needed for v1, where the i/o completion is not
> > handled in the dma driver.
> > 
> > Signed-off-by: Andy Gross <andy.gross@linaro.org>
> > Signed-off-by: Varadarajan Narayanan <varada@codeaurora.org>
> > ---
> >  drivers/spi/spi-qup.c | 15 +++++++++++++--
> >  1 file changed, 13 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
> > index 872de28..bd53e82 100644
> > --- a/drivers/spi/spi-qup.c
> > +++ b/drivers/spi/spi-qup.c
> > @@ -510,9 +510,9 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
> >  
> >  	writel_relaxed(qup_err, controller->base + QUP_ERROR_FLAGS);
> >  	writel_relaxed(spi_err, controller->base + SPI_ERROR_FLAGS);
> > -	writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
> >  
> >  	if (!xfer) {
> > +		writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
> 
>  This does look correct to remove acknowledging the QUP in normal case and
>   do it conditionally only when xfer = NULL.

This is to probably mask the issue of getting erroneous/spurious IRQs.

> 
> >  		dev_err_ratelimited(controller->dev, "unexpected irq %08x %08x %08x\n",
> >  				    qup_err, spi_err, opflags);
> >  		return IRQ_HANDLED;
> > @@ -540,7 +540,15 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
> >  		error = -EIO;
> >  	}
> >  
> > -	if (!spi_qup_is_dma_xfer(controller->mode)) {
> > +	if (spi_qup_is_dma_xfer(controller->mode)) {
> > +		writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
> > +		if (opflags & QUP_OP_IN_SERVICE_FLAG &&
> > +		    opflags & QUP_OP_MAX_INPUT_DONE_FLAG)
> > +			complete(&controller->rxc);
> > +		if (opflags & QUP_OP_OUT_SERVICE_FLAG &&
> > +		    opflags & QUP_OP_MAX_OUTPUT_DONE_FLAG)
> > +			complete(&controller->txc);
> > +	} else {
> 
>  Is this because in patch #8 that we do not populate the dma callback
>  for v1. If that is done, this should not be required at all, as the
>  complete would be signalled from the dma callback.

I believe that is true.  There shouldn't be any IRQs for DMA enabled
transactions (at least BAM-dma).
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Sricharan Ramabadhran June 15, 2017, 5:52 a.m. UTC | #3
Hi Andy,

On 6/15/2017 1:36 AM, Andy Gross wrote:
> On Wed, Jun 14, 2017 at 12:51:11PM +0530, Sricharan R wrote:
>> Hi Varada,
>>
>> On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote:
>>> This is needed for v1, where the i/o completion is not
>>> handled in the dma driver.
>>>
>>> Signed-off-by: Andy Gross <andy.gross@linaro.org>
>>> Signed-off-by: Varadarajan Narayanan <varada@codeaurora.org>
>>> ---
>>>  drivers/spi/spi-qup.c | 15 +++++++++++++--
>>>  1 file changed, 13 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
>>> index 872de28..bd53e82 100644
>>> --- a/drivers/spi/spi-qup.c
>>> +++ b/drivers/spi/spi-qup.c
>>> @@ -510,9 +510,9 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
>>>  
>>>  	writel_relaxed(qup_err, controller->base + QUP_ERROR_FLAGS);
>>>  	writel_relaxed(spi_err, controller->base + SPI_ERROR_FLAGS);
>>> -	writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
>>>  
>>>  	if (!xfer) {
>>> +		writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
>>
>>  This does look correct to remove acknowledging the QUP in normal case and
>>   do it conditionally only when xfer = NULL.
> 
> This is to probably mask the issue of getting erroneous/spurious IRQs.
> 

 hmm, now the QUP_OPERATIONAL is not written to acknowledge the interrupts in
 normal case seems to be wrong.

>>
>>>  		dev_err_ratelimited(controller->dev, "unexpected irq %08x %08x %08x\n",
>>>  				    qup_err, spi_err, opflags);
>>>  		return IRQ_HANDLED;
>>> @@ -540,7 +540,15 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
>>>  		error = -EIO;
>>>  	}
>>>  
>>> -	if (!spi_qup_is_dma_xfer(controller->mode)) {
>>> +	if (spi_qup_is_dma_xfer(controller->mode)) {
>>> +		writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
>>> +		if (opflags & QUP_OP_IN_SERVICE_FLAG &&
>>> +		    opflags & QUP_OP_MAX_INPUT_DONE_FLAG)
>>> +			complete(&controller->rxc);
>>> +		if (opflags & QUP_OP_OUT_SERVICE_FLAG &&
>>> +		    opflags & QUP_OP_MAX_OUTPUT_DONE_FLAG)
>>> +			complete(&controller->txc);
>>> +	} else {
>>
>>  Is this because in patch #8 that we do not populate the dma callback
>>  for v1. If that is done, this should not be required at all, as the
>>  complete would be signalled from the dma callback.
> 
> I believe that is true.  There shouldn't be any IRQs for DMA enabled
> transactions (at least BAM-dma).

 yeah, the above hunk looks like is ADM specific, not sure why ADM cannot
 work with dma callbacks.

Regards,
 Sricharan
diff mbox

Patch

diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
index 872de28..bd53e82 100644
--- a/drivers/spi/spi-qup.c
+++ b/drivers/spi/spi-qup.c
@@ -510,9 +510,9 @@  static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
 
 	writel_relaxed(qup_err, controller->base + QUP_ERROR_FLAGS);
 	writel_relaxed(spi_err, controller->base + SPI_ERROR_FLAGS);
-	writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
 
 	if (!xfer) {
+		writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
 		dev_err_ratelimited(controller->dev, "unexpected irq %08x %08x %08x\n",
 				    qup_err, spi_err, opflags);
 		return IRQ_HANDLED;
@@ -540,7 +540,15 @@  static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
 		error = -EIO;
 	}
 
-	if (!spi_qup_is_dma_xfer(controller->mode)) {
+	if (spi_qup_is_dma_xfer(controller->mode)) {
+		writel_relaxed(opflags, controller->base + QUP_OPERATIONAL);
+		if (opflags & QUP_OP_IN_SERVICE_FLAG &&
+		    opflags & QUP_OP_MAX_INPUT_DONE_FLAG)
+			complete(&controller->rxc);
+		if (opflags & QUP_OP_OUT_SERVICE_FLAG &&
+		    opflags & QUP_OP_MAX_OUTPUT_DONE_FLAG)
+			complete(&controller->txc);
+	} else {
 		if (opflags & QUP_OP_IN_SERVICE_FLAG)
 			spi_qup_read(controller, xfer);
 
@@ -553,6 +561,9 @@  static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id)
 	controller->xfer = xfer;
 	spin_unlock_irqrestore(&controller->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)
 		complete(&controller->done);