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 <mmccl...@codeaurora.org> > Signed-off-by: Varadarajan Narayanan <var...@codeaurora.org> > --- > 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(&controller->lock, flags); > + spin_lock(&controller->lock); > xfer = controller->xfer; > controller->xfer = NULL; > - spin_unlock_irqrestore(&controller->lock, flags); > + spin_unlock(&controller->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(&controller->lock, flags); > - controller->error = error; > - 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) > + done = true; > + > + spin_lock(&controller->lock); > + controller->error = error; > + controller->xfer = done ? NULL : xfer; > + spin_unlock(&controller->lock); > + > + if (done) > complete(&controller->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
