From mboxrd@z Thu Jan 1 00:00:00 1970 From: Varadarajan Narayanan Subject: [PATCH 11/18] spi: qup: properly detect extra interrupts Date: Wed, 14 Jun 2017 11:22:24 +0530 Message-ID: <1497419551-21834-12-git-send-email-varada@codeaurora.org> References: <1497419551-21834-1-git-send-email-varada@codeaurora.org> Cc: Varadarajan Narayanan , Matthew McClintock To: broonie@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, andy.gross@linaro.org, david.brown@linaro.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org Return-path: In-Reply-To: <1497419551-21834-1-git-send-email-varada@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org 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(&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