[PATCH 11/18] spi: qup: properly detect extra interrupts
From: Varadarajan Narayanan <hidden>
Date: 2017-06-14 05:54:03
Also in:
linux-arm-msm, linux-spi, lkml
Subsystem:
arm/qualcomm mailing list, spi subsystem, the rest · Maintainers:
Mark Brown, Linus Torvalds
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 <redacted> Signed-off-by: Varadarajan Narayanan <redacted> --- 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); 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); 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(&controller->lock, flags); - controller->xfer = NULL; if (!ret) ret = controller->error; spin_unlock_irqrestore(&controller->lock, flags);
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation